Maximising the use of recycled andsecondary aggregates: examples fromHampshire

Prepared for Partners in Innovation Programme, Department

of Trade and Industry

J M Reid, J Pittman, C R Sowerby and J Hibbert

TRL Report TRL651

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First Published 2006ISSN 0968-4107ISBN 1-84608-650-7Copyright TRL Limited 2006.

This report has been produced by TRL Limited, under/as partof a contract placed by the Department of Trade and Industry.Any views expressed in it are not necessarily those of theDepartment.

TRL is committed to optimising energy efficiency, reducingwaste and promoting recycling and re-use. In support of theseenvironmental goals, this report has been printed on recycledpaper, comprising 100% post-consumer waste, manufacturedusing a TCF (totally chlorine free) process.

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CONTENTS

Page

Executive Summary 1

1 Introduction 3

1.1 Sustainability and local authorities 3

1.2 Who should read this report? 3

1.3 Project aims and objectives 3

1.4 Structure of the report 4

2 Implementing sustainability in Hampshire 4

2.1 Highway maintenance in Hampshire 4

2.2 Minerals and waste in Hampshire: an integrated approach 5

3 Availability of recycled and secondary aggregates in Hampshire 6

3.1 Current use of aggregates in Hampshire 6

3.2 Potential future use of recycled and secondary aggregates 7

3.3 Actions required to achieve the ‘stretching best practice’scenario targets 8

3.3.1 Infrastructure 9

3.3.2 Market development 9

3.3.3 Standards and specifications 10

4 Use of recycled and secondary aggregates in Hampshire:demonstration projects 11

4.1 Demonstration projects 11

4.1.1 Demonstration Project 1: Embankment stabilisationon the A325 at Alice Holt 11

4.1.2 Demonstration Project 2: Recycled asphalt in footwayworks, B3047 at Martyr Worthy 12

4.1.3 Demonstration Project 3: Recycled surface dressingsweepings at sites across Hampshire 13

4.1.4 Demonstration Project 4: Bar End Household WasteRecycling Centre (HWRC) 13

4.1.5 Demonstration Project 5: A3 Bus Priority Corridor,Portsmouth to Clanfield 13

4.1.6 Demonstration Project 6: North Popley development,Basingstoke 14

4.2 Factors influencing the use of recycled and secondaryaggregates in the demonstration projects 14

4.3 Benefits from the use of recycled and secondaryaggregates in the demonstration projects 15

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5 Planning: minerals and waste development framework 15

5.1 Principles 15

5.2 Policies 20

5.3 Provision of recycling capacity 20

5.4 Supply of minerals 21

5.5 Conclusion 22

6 Issues, guidance and actions: Recycling in transportinfrastructure revisited 22

6.1 Issues 22

6.1.1 Specifications 22

6.1.2 Test methods 22

6.1.3 Reliability and quality control 22

6.1.4 Environmental concerns 25

6.1.5 Waste management regulations 27

6.1.6 Conditions of contract 27

6.1.7 Planning 28

6.1.8 Supply and demand 28

6.1.9 Economics 29

6.1.10 Lack of awareness 29

6.2 Summary: progress and the way forward 31

7 Conclusions 31

8 Acknowledgements 32

9 References 32

Abstract 34

Related publications 34

Appendix A: Summary versions of demonstration Appendix A – 1projects

Appendix B: Demonstration projects: full case Appendix B – 1studies

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Executive Summary

! Spent railway ballast.

! Incinerator bottom ash aggregate from three waste-to-energy plants in Hampshire.

! Recycled glass, plastic and tyres.

Current (2004) use of recycled and secondaryaggregates in Hampshire was estimated to be 686,000tonnes per year, approximately 13.4% of the totalaggregate use. Most of this was recycled aggregates frominert CD&EW, with significant contributions from spentrailway ballast and highway works, and most of it wasused as relatively low value unbound granular fill. Underthe ‘stretching best practice’ scenario of the MRS thiscould rise to 1,104,530 tonnes per year by 2020, 21.6% oftotal aggregate use. This arises from greater use ofrecycled aggregates from inert CD&EW, more recycling inhighway works and use of incinerator bottom ashaggregate. Up to 20% of the aggregates should be used inhigh value applications such as concrete and asphalt. Thesefigures were fed into the MRS process.

In order to achieve these targets, a number of actionswill be required. Additional infrastructure will be requiredto process the recycled and secondary materials intoacceptable aggregates; quality protocols and specificationswill need to be enforced to ensure the materials are usedappropriately; education and market development will berequired; and the planning system will need to encouragerecycling through tools such as the Demolition Protocoland the Sustainable Building Code of Practice. HampshireCounty Council and other major clients can set an exampleby maximising recycling in their operations andencouraging it in others.

Six demonstration projects were developed to illustratehow the use of recycled and secondary aggregates can bemaximised in Hampshire:

! Demonstration Project 1: Embankment Stabilisation onA325 at Alice Holt.

! Demonstration Project 2: Recycled Asphalt in FootwayWorks on B3047 at Martyr Worthy.

! Demonstration Project 3: Recycled Surface DressingSweepings.

! Demonstration Project 4: Bar End Household WasteRecycling Centre.

! Demonstration Project 5: A3 Bus Priority Corridor,Portsmouth to Clanfield.

! Demonstration Project 6: North Popley Development,Basingstoke.

A wide range of applications were covered, fromgeneral and selected granular fill, capping and unboundsub-base, through to cement stabilised sub-base, coldrecycled bitumen bound material, surface dressing andstructural concrete. The demonstration projects covermany of the potential applications for recycled andsecondary aggregates in Hampshire.

One of the ways in which sustainable construction can beachieved is by the use of recycled and secondary aggregatesinstead of primary aggregates. This has advantages in termsof preservation of natural resources and protection of theenvironment, two of the pillars that underlie the concept ofsustainability. There have been many developments inrecent years in terms of standards, specifications andprotocols that permit the use of recycled and secondaryaggregates, but experience has shown that the critical factoris often the active involvement of the client. Localauthorities are major construction clients, particularly inareas such as highways, and hence are able to exert aconsiderable influence on the use of construction materialsin their area. They are also responsible for a number ofrelated activities, such as waste management and planning,that can have a significant effect on the extent to whichrecycling of all kinds takes place. This report describes theexperience of Hampshire County Council, and shows how alocal authority that is committed to sustainability andprepared to take action to implement its principles canachieve considerable success in maximising the use ofrecycled and secondary aggregates.

Hampshire County Council has a firm commitment tosustainability, embodied in Aim 2 of its corporate strategy,which is to protect the environment by promoting theprinciples of environmental sustainability. These principlesare embodied in formal council policies that directly affectthe activities of its departments, including the HighwaysGroup. The delivery of highway maintenance services inHampshire is achieved through a partnership between theCounty Council, Raynesway Construction Southern Ltd(RCS) and Foster Yeoman Limited.

Other sustainability-related initiatives include ProjectIntegra, Hampshire’s integrated household waste strategyand the Hampshire Natural Resources Initiative, which aimsto achieve a step change in the way natural resources areperceived and used in Hampshire. Bringing all theseinitiatives together is the Material Resources Strategy(MRS), a stakeholder process involving community andindustry representatives working in partnership withHampshire County Council, Portsmouth and SouthamptonCity Councils and Project Integra. This integrated approachaims to change the way material resources are used tomaximise efficiency and minimise waste. As part of theMRS process, estimates had to be made of current levels ofrecycling for a range of materials, including aggregates, andpotential levels estimated for 2010 and 2020 under twoscenarios: business as usual; and stretching best practice.

TRL Limited carried out assessments for a number ofrecycled and secondary aggregates that were relevant forHampshire, and compared this with the expectedproduction of primary aggregates and overall demand foraggregates. The materials considered were:

! Recycled aggregates from inert construction demolitionand excavation waste (CD&EW).

! Highway maintenance and new construction.

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A number of factors were critical for the success ofrecycled and secondary aggregate use in Hampshire:

! There was a clear lead from the client and coordinationwith other recycling initiatives.

! There was early involvement of contractors and otherrelevant stakeholders.

! Logistical arrangements were put in place, e.g. storagedepots and recycling plants.

! Locally available materials were used.

! Modern specifications, design guides and qualityprotocols were used and new ones were developedwhere necessary.

The use of recycled and secondary aggregates not onlyresulted in environmental gains, such as reduced use ofprimary aggregates, reduced disposal of materials to landfilland reduced emissions of CO

2, but also reduced costs in

most cases. The experience of Hampshire County Council isthus an example for other local authorities of how to tacklesustainability issues in an integrated way that will yieldbenefits for local residents and the country as a whole.

A number of issues were identified as key to increaseduse of recycled and secondary aggregates in a TRLpublication ‘Recycling in transport infrastructure’ in 2001.These issues were reviewed and it was found that there hadbeen considerable progress on a number of the issues,particularly in the greater use of partnering and earlycontractor involvement, updating of specifications,standards and quality protocols, resolution of conflicts withthe Waste Management Licensing regime and addressingthe lack of awareness among construction professionals andmajor clients. The WRAP Aggregates Programme has madea very significant contribution to this, particularly throughtheir web site www.aggregain.org.uk.

A number of areas remain where obstacles to recyclingcould still occur, such as obtaining planning permission forrecycling facilities, developing protocols for secondaryaggregates and addressing the lack of awareness issue forthe Small to Medium Enterprises (SME) sector. It isimportant that use of recycled and secondary aggregates isseen as part of an overall programme on sustainability andco-ordinated with other activities. The MRS approachadopted by Hampshire County Council, Portsmouth andSouthampton City Councils provides a good example ofhow this can be achieved.

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1 Introduction

1.1 Sustainability and local authorities

Sustainability has become a key concept world-wide inrecent years, and has been incorporated in UK governmentpolicy through a number of documents (DETR, 1999;2000). It was originally defined in the Brundtland Reportas ‘development which meets the needs of the presentwithout compromising the ability of future generations tomeet their own needs’ (World Commission onEnvironmental Development, 1987). It covers a widerange of activities which are inter-related and should notbe addressed in isolation, including resource use, wasteproduction and disposal, energy, emissions and social andeconomic issues. In the UK they have been grouped intofour objectives (DETR, 1999):

! Social progress which recognises the needs of everyone.

! Effective protection of the environment.

! Prudent use of natural resources.

! Maintenance of high and stable levels of economicgrowth and employment.

One of the ways in which sustainability can beimplemented in construction is by the use of recycled andsecondary aggregates in place of primary aggregates. Thisis consistent with the objectives of ‘prudent use of naturalresources’ and ‘effective protection of the environment’.One of the major uses of aggregates in the UK is in roadconstruction and maintenance, and this area offers manyopportunities for use of recycled and secondary aggregates(Sherwood, 1995; Reid and Chandler, 2001).

Local authorities have been at the forefront ofinterpreting what this new philosophy is about andimplementing it in their activities. In England and Wales,county councils, unitary authorities and metropolitanboroughs have a wide range of responsibilities wheresustainability issues are relevant, including wastecollection and disposal and construction-related activitiessuch as highway maintenance, schools and housing. Theyare also planning authorities with responsibilities includingdeciding applications for new mineral workings, wastedisposal and recycling facilities or extensions to existingfacilities, new developments and redevelopment ofexisting sites and making provision to meet centralgovernment targets for mineral production and wastedisposal. They thus have a very large influence onactivities in their area, both as client and enforcingauthority, and can affect the extent to which the principlesof sustainability are implemented.

Most local authorities have some reference tosustainability in their high level strategic objectives. Successin delivery of these objectives relies on establishing a linkbetween these strategic goals and what happens on theground. This requires a clear lead from the top and theestablishment of policies that translate the objectives intoaction. It also requires a major change in culture and attitudeon the part of the staff of the council and those oforganisations working for them. If these conditions are met,major advances in sustainability can be achieved.

By being proactive in increasing the use of recycled andsecondary aggregates, Hampshire County Council andother local authorities are responding to communityconcerns about the impact of mineral working and wastedisposal and community desire for a more sustainableapproach to use of material resources. The role of localauthorities and the public sector generally in responding tocommunity concerns and desires – closing the loop – is akey driver for change. This involves linking functions suchas minerals and waste, procurement and highways to createmarket demand for products such as recycled andsecondary aggregates. This forms part of the broaderagenda for sustainable consumption and production, inwhich local authorities are heavily involved.

1.2 Who should read this report?

This report deals with the activities of Hampshire CountyCouncil and the neighbouring City Councils ofSouthampton and Portsmouth, their partners, contractors,suppliers and other relevant stakeholders and their efforts toimplement sustainability in their activities, particularly inincreasing the use of recycled and secondary aggregates inplace of primary aggregates. The emphasis is mainly onhighway maintenance, new construction and relatedactivities, but these are dealt with in the wider context ofoverall waste and material use. It illustrates how theintegrated approach adopted by Hampshire, Southamptonand Portsmouth can lead to significant increases in the useof recycled and secondary aggregates.

The report should be read by local authority personnelwho are interested in implementing the principles ofsustainability in their operations, particularly those involvedin highway maintenance and construction. It will also be ofinterest to contractors, designers and suppliers working forlocal authority highways departments and planners andwaste management officers in local authorities.

1.3 Project aims and objectives

The work described in this report was carried out by TRLLimited under a Partners in Innovation project funded by theDepartment of Trade and Industry, with in-kind contributionsfrom a range of individuals and organisations includingHampshire County Council, Raynesway ConstructionSouthern, Foster Yeoman, the Environment Agency, Dean &Dyball and the Institution of Civil Engineers.

The aim of the project was to provide technicalinformation to enable the maximum use to be made ofrecycled and secondary aggregates (RSA) in the County ofHampshire1 and the associated urban areas of Southamptonand Portsmouth. It was a linked research, development anddemonstration project which proceeded in two stages:

! Stage 1: A review of information on current andpotential use of recycled and secondary aggregates andthe technical and regulatory mechanisms by which theseare controlled, leading to identification of requirements

1 In this report, ‘Hampshire’ is used to denote the county of Hampshireand the urban areas of Portsmouth and Southampton.

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for processing and other infrastructure to enable themaximum potential use to be achieved.

! Stage 2: A series of research and demonstration projectsinvolving the use of recycled and secondary aggregatesin a variety of applications that will illustrate how thepotential can be achieved and how obstacles can beovercome.

This is the final report for the project and summarisesthe work carried out in both stages of the project. Thework carried out in Stage 1 is described in detail bySowerby et al. (2005).

1.4 Structure of the report

In Chapter 2 the integrated approach to sustainabilityadopted by Hampshire County Council is described, withparticular emphasis on highway maintenance and mineraland waste policy. The current and potential futureavailability of recycled and secondary aggregates inHampshire, and the contribution they can make to theoverall aggregate requirements of the county are describedin Chapter 3. The ways in which these aggregates can beused are described by means of a number of demonstrationprojects in Chapter 4, and the effect on the minerals andwaste development framework are described in Chapter 5.In Chapter 6 a number of potential drivers and obstacles togreater use of recycled and secondary aggregates arediscussed and conclusions are given in Chapter 7.Summary and full versions of the demonstration projectsare give in Appendices A and B respectively.

2 Implementing sustainability inHampshire

2.1 Highway maintenance in Hampshire

Hampshire is a county on the south coast of England,roughly half way between the east and west ends of thecountry. It has a population of 1,240,000 and covers anarea of 367,680 hectares, making it one of the largest non-metropolitan or ‘shire’ counties in England(www.hants.gov.uk/abouthnt.html). Most of the county iswithin 1-2 hours of London by main-line rail services ormotorways. The major cities of Southampton andPortsmouth, on the south coast, are not part of the countybut are covered by the respective city councils. The countyis partly rural but many areas are heavily developed,particularly around Basingstoke and the towns of urbansouth Hampshire (Eastleigh, Fareham, Gosport, Havant).

In England and Wales, county councils are responsiblefor the maintenance of public highways with theexception of trunk roads and motorways. This covers awide range of situations, from lightly trafficked roads inrural areas and housing estates to major principal roads(‘A’ roads) that are very heavily trafficked and connectwith the trunk road and motorway network. Highwaymaintenance covers a wide range of operations, frompatching and surface dressing to complete reconstructionof life-expired carriageways. The county councils are

also involved in new construction, from ensuring thatnew roads in housing and industrial estates areconstructed in accordance with the local authoritiesadoption specifications to major schemes such asbypasses. County councils are thus in a very powerfulposition to influence the amount of recycling and the useof recycled and secondary aggregates in highwaymaintenance and new construction in their areas.

Hampshire County Council is responsible for maintainingmore than 6,000 miles of road and a similar length offootways. The maintenance of Hampshire’s road network iscarried out to ensure that the highways are safe and that thepublic can use them without obstruction. The HampshireHighways Group, a branch of the County Council’sEnvironment Department, carries this out in accordancewith set policies. Hampshire has been at the forefront ofdeveloping a systematic approach to the maintenance andmanagement of the highway network and was influential inthe development of the local authorities association’s Codeof Practice for Highway Maintenance (Anon, 2005).

Hampshire County Council has a firm commitment tosustainability. Aim 2 of the council’s corporate strategy isto protect the environment by promoting the principles ofenvironmental sustainability. Sustainable developmentimplies the following principles which can be adopted forhighway maintenance operations:

! A reduction in the consumption of natural resources,including energy. Non-renewable resources should besubstituted with renewable resources.

! Waste should be reduced.

! Waste should be reused or recycled.

! Biodiversity should be preserved or enhanced.

! Valuable natural and physical assets and amenitiesshould be preserved and protected.

These principles are embodied in a formal councilpolicy which states that Hampshire County Council, as thehighway authority, shall consider environmental factorswhenever designing a maintenance scheme or planning amaintenance operation. The choice of materials andprocesses that preserve or enhance the environment shouldhave due regard to the health and safety of the road user.This policy drives the actions of the HampshireEnvironment Department and clearly favours recyclingand the use of recycled and secondary aggregates,provided this does not adversely affect the performance orsafety of the highway network.

As part of its commitment to sustainability, HampshireCounty Council signed a Public Service Agreement (PSA)with the Government in April 2002 covering the period upto March 2005. The Public Service Agreement requiresHampshire County Council to achieve more demandingperformance targets than would otherwise be expected.One of the targets was to recycle an additional 40,000tonnes per annum of household, commercial and industrialwaste through development of a natural resourcemanagement approach. Highway maintenance and newconstruction were identified as key areas which couldcontribute significantly to meeting this target.

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The delivery of highway maintenance services inHampshire is achieved through a partnership between theCounty Council, Raynesway Construction Southern Ltd(RCS) and Foster Yeoman Limited. The partnership has anumber of benefits including a shared feeling of projectownership, agreed priorities and common goals by all thestakeholders. Stable relationships are developed betweenthe partners, which generates and stimulates strategicthinking. The arrangement allows efficiencies inprogramming by linking project clusters to projectpartners. It enables the development of new materials andspecifications, with input and advice from theEnvironment Agency where necessary. The project has thefollowing sustainability related objectives:

! Identify opportunities for changing working practices onhighway maintenance to optimise reuse and recycling ofconstruction waste.

! Reduce construction waste and use recycled andsecondary aggregates.

! Draw on each others strengths for the mutual benefit ofthe partners and the people of Hampshire.

The partnership covers routine highway maintenancework. Large capital projects, such as major maintenanceschemes, are let by competitive tender.

2.2 Minerals and waste in Hampshire: an integratedapproach

The Hampshire, Portsmouth and Southampton Mineralsand Waste Local Plan was adopted by the three councils inDecember 1998. The plan period was to December 2001with provision for a seven year land bank for sand andgravel to 2008. A review of the Plan commenced, and thethree authorities reconsidered the approach to the review inthe light of comments arising from the stakeholderdialogue and the implications of the Planning andCompulsory Purchase Bill. They agreed that a review ofwaste policies should be urgently progressed and that anintegrated Hampshire Minerals and Waste DevelopmentFramework (HMWDF) be prepared.

As part of the process of producing a context for theHMWDF, the joint municipal waste management strategyand work through the Natural Resources Initiative onsocietal change, the councils instigated a stakeholderconsultation process called the Material ResourcesStrategy (MRS). This involved community and industryrepresentatives working in partnership with HampshireCounty Council, Portsmouth and Southampton CityCouncils and Project Integra (Hampshire’s integratedhousehold waste strategy) and the Hampshire NaturalResources Initiative (HNRI), which aims to achieve a stepchange in the way natural resources are perceived and usedin Hampshire. Details of Project Integra and HNRI can befound at the web sites www.integra.org.uk andwww.hnri.co.uk respectively.

The MRS addressed the use of all material resources,including municipal, construction, commercial andagricultural waste in Hampshire. The philosophy was toregard arisings of all materials as a resource rather than awaste, to maximise reuse, recycling and recovery,

minimise arisings of waste and minimise the amount goingto landfill. A key part of the strategy was to minimiseextraction of primary resources, such as aggregates, bybetter process and product design and by maximising theuse of recycled and secondary aggregates.

The MRS proceeded by means of a series of stakeholderworkshops, in parallel with which a review was undertakenof all the main material and waste streams arising inHampshire. For each material stream, estimates were madeof the current level of arisings and recycling, and potentiallevels in 2010 and 2020 under two scenarios:

! A ‘business as usual’ scenario that had regard toessential change, e.g. the requirements of existing andnew legislation, regulations and statutory targets.

! A ‘stretching best practice’ scenario that set out the bestthat could reasonably be achieved with a concertedeffort, having regard to ‘state of the art’ approachesoverseas and in the UK.

The estimates for each material were reviewed by anindependent panel of interested stakeholders and subjectedto an independent validation review before beingincorporated into the MRS. TRL was already preparingestimates for a range of recycled and secondary aggregatesunder the PII project (see 1.4 above), and the form inwhich the information was collected was adapted tocomply with the requirements for the MRS. In addition toestimates of quantities under the two scenarios, issues suchas collection and infrastructure requirements, marketdevelopment, education, financial issues, risks and widerissues were addressed. A separate report on constructionwaste and soil was produced specifically for the MRS(Sowerby and Reid, 2005). The findings of these studiesare discussed in Chapter 3.

The outcome of the MRS process was published as‘More from Less’ in March 2005 on behalf of thecommunity stakeholders by Hampshire County Council,Portsmouth and Southampton City Councils and ProjectIntegra. It is intended as a primary reference point to guideand integrate three key work areas:

! Production of the statutory joint minerals and wastedevelopment framework.

! Development of plans for managing municipal wasteunder Project Integra.

! Implementation of societal change objectives via theHampshire Natural Resources Initiative.

The document reviews a number of topics, includingresource efficiency and reducing wastage, maximisingreuse, recycling and composting, dealing with unavoidablewastes, meeting the need for minerals and the need for newinfrastructure and sites. For each topic the current situationis reviewed, ways forward are suggested, actions listed andtargets set. The overall vision of ‘More from Less’ is that:we will change the way we use material resources tomaximise efficiency and minimise wastage. To deliver thisthey have identified four aims:

! To extract primary materials only where it can be shownthat the need cannot be met in a more sustainable way.

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! To change minds and behaviours to use all resourcesefficiently and minimise wastage at all stages ofproduction and consumption.

! Where waste is produced to maximise opportunities forbusiness and the community to reuse, recycle andcompost such waste to produce sustainable products.

! To recover value from and dispose of unavoidable wasteusing sustainable means, as far as possible avoiding thelandfilling of biodegradable/recyclable waste.

Clearly, increasing the use of recycled and secondaryaggregates in activities such as highway maintenance is acrucial part of achieving these aims. Details of how thiscan be carried out are given in Chapter 4. It is important toremember that this is part of an overall strategy for dealingwith minerals and waste, and not an end in itself.

3 Availability of recycled and secondaryaggregates in Hampshire

3.1 Current use of aggregates in Hampshire

Hampshire is a county with no reserves of hard rock, butwith extensive deposits of sand and gravel which havebeen worked for many years. Marine dredged sand andgravel is available from the English Channel, and is landedat a number of wharves in Portsmouth and Southampton.Crushed rock is imported into the county through thesewharves, and is also delivered by rail to several depots inthe Southampton and Portsmouth area. Good quality dataare available on the amounts of these primary aggregatesproduced each year. These are published in the annualAggregates Monitoring (AM) reports produced by theSouth East England Regional Assembly. The data for 2002are summarised in Table 1. The total arisings of primaryaggregates were estimated to be 4,944,000 tonnes per

annum, of which 4,434,500 tonnes (90%) was used in thecounty, with the balance exported to neighbouringcounties and London.

These primary aggregates are supplemented by recycledand secondary aggregates from a variety of sources. ForHampshire, the potentially significant materials werefound to be:

! Recycled aggregates from inert construction demolitionand excavation waste (CD&EW).

! Recycled aggregates and asphalt from highwaymaintenance and new works.

! Spent railway ballast.

! Incinerator bottom ash aggregate (IBAA) fromprocessing of incinerator bottom ash (IBA).

Data on the current use and potential availability ofthese materials was much less accurate than for theprimary aggregates. Estimates of production of recycledaggregates from CD&EW are available at national andregional level from surveys carried out every two years forthe Office of the Deputy Prime Minister (ODPM, 2002aand 2004). The data has large error margins and cannot bebroken down to county level. Estimates of CD&EWrecycled at licensed waste management sites in Hampshirewere obtained from data collected by the EnvironmentAgency. This data is subject to a number of uncertaintiesdue to the way it is recorded by the site operators(Sowerby et al., 2005). It also underestimates the totalamount of recycled CD&EW because it does not includerecycling at sites exempt from the waste managementlicensing regulations. This category includesredevelopment projects where materials are produced,processed and reused on site. Discussions with suppliers ofrecycled aggregates and other stakeholders helped toprovide estimates of the quantity of inert CD&EWpotentially recyclable as aggregate and the amount actually

Table 1 Current aggregate use in Hampshire (tonnes/year)

Amount arising in Hampshire(produced in Hampshire

Material or imported into the county) Amount used in Hampshire

PrimaryLand based sand and gravel 2,193,000 2,010,500Marine dredged sand and gravel 1,715,000 1,638,000Rail import of crushed rock 600,000 500,000Marine imports of crushed rock 436,000 286,000Total sand and gravel 3,908,000 3,648,500Total crushed rock 1,036,000 786,000Total primary aggregates 4,944,000 4,434,500

Recycled and secondary aggregates Amount suitable for use as aggregates Amount used as aggregates

Recycled aggregate from inert CD&EW 750,000 500,000Highways new works and maintenance Not known 45,000Spent railway ballast 140,000 140,000Incinerator bottom ash aggregate (IBAA) 30,000 1,000Recycled glass 36,500 0Recycled plastics 33,500 0Recycled tyres 10,400 0Total recycled and secondary aggregates 1,000,400 686,000Total aggregate use in Hampshire – 5,119,500Proportion of recycled and secondary aggregates – 13.4%

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recycled as aggregate. These were estimated as 750,000and 500,000 tonnes per annum respectively. The figuresare shown in Table 1. This is by far the largest source ofrecycled aggregates in Hampshire.

The total amount of inert CD&EW produced in Hampshirewas estimated to be about 1,540,000 tonnes per annum. Ofthis about half, 750,000 tonnes is estimated to be potentiallyrecyclable as aggregate. The remainder is thought to consistof excavation waste, largely clay, silt and chalk which cannotbe recycled as aggregate, or mixed waste in which potentiallyrecyclable material is mixed with soil or excessive amounts ofmaterial such as timber, plasterboard, plastic or metal. Aboutone third of the total inert CD&EW, 500,000 tonnes iscurrently recycled as aggregate. This is similar to a nationalsurvey which found an overall rate of recycling of inertCD&EW as aggregate of about 36% in the South East Regionin 2001 (ODPM, 2002a).

Highway maintenance works are a major potentialsource of recycled aggregates, in the form of asphaltplanings, concrete kerbs, granular sub-base and subsoil. Anumber of techniques are available for recycling thesematerials (see Chapter 4) and these have been increasinglyused in Hampshire in recent years; the proportion ofhighway maintenance arisings recycled by HampshireCounty Council rose from 10% in 1997/98 to 66% in2000/01 (Reid and Chandler, 2001). The estimate for theamount recycled in 2003/04 is 45,000 tonnes, and this isshown in Table 1. The total arisings were not known.These figures were supplied by Hampshire County CouncilHighways Group.

Another major source of recycled aggregates inHampshire is spent railway ballast. This comes in to therail depots in South Hampshire from all over the SouthEast of England and is predominantly primary aggregatesuch as granite mixed with soil and sub-ballast material. Itis mainly used as capping material, sub-base and generalfill. All the railway ballast is handled by Foster YeomanLtd; they provided the figure in Table 1 and indicated thatthe supply is fairly constant. The total arisings are about140,000 tonnes per annum, and all of this is used asrecycled aggregate.

The only other material that is potentially significant asaggregate in Hampshire is incinerator bottom ash aggregate(IBAA). Hampshire has developed three Energy from Wastefacilities as part of an integrated strategy to handlemunicipal waste; now that they are fully operational, theywill produce a total of about 100,000 tonnes of incineratorbottom ash per year. This can be processed and used asaggregate (IBAA), otherwise it has to be disposed of tolandfill. A trial was carried out in 2004 using 1,000 tonnesof IBAA in a road construction (see Chapter 4), and thisfigure is shown in Table 1. At the time only one Energyfrom Waste plant was operational, producing about 30,000tonnes of incinerator bottom ash per year.

Other materials that could potentially be used asaggregate include glass, plastic and tyres. Estimates for theamounts of these materials that are potentially suitable forrecycling as aggregate are shown in Table 1. None of thesematerials are currently used as aggregates in Hampshire.Glass is collected by Midland Glass in Southampton and is

recycled into new glass, which is a higher valueapplication than use as aggregates, although the use ofground glass as bedding sand and as aggregate in asphalt iswell established. Plastic and tyres can also be used asaggregates, but it is expensive to process them for theseapplications compared to other end uses, and compared tousing other primary, recycled or secondary aggregates forthe same applications.

The figures indicate that the total use of aggregates inHampshire is about 5,119,500 tonnes per annum of which686,000 tonnes (13.4%) are recycled and secondaryaggregates. Overall figures for aggregate use in Englandfor 2001 (Barritt, 2003) suggest that recycled andsecondary aggregates account for about 23% of totalaggregate use. The reason for the discrepancy is not clear.The estimate of recycled aggregates produced from inertCD&EW for Hampshire may be an underestimate becauseit does not include material recycled at exempt sites, but itis thought that this could not account for all the difference.The figures should be viewed as indicative, with largemargins of uncertainty, not as accurate estimates. Thisdifference between the amounts predicted from nationalsurveys and the amounts that were actually found to beavailable at county level has important implications whenconsidering Hampshire’s allocations of recycled andsecondary aggregates in statutory minerals plans in thefuture (see Chapter 5).

The end use of most recycled and secondary aggregateswas found to be mainly as relatively low value unboundgranular materials, with some being used as capping andsub-base but only very small amounts in higher valuebound applications such as concrete and asphalt. Thisagrees with the findings of Barritt (2003) that recycled andsecondary aggregates in England are mostly used in lowvalue unbound applications.

3.2 Potential future use of recycled and secondaryaggregates

The survey of existing use found that there wasconsiderable scope for increasing the quantities of recycledand secondary aggregates used in Hampshire, and also forusing them in higher value applications. In conjunctionwith the development of the MRS, estimates for potentialuse in 2010 and 2020 were made under the ‘stretching bestpractice’ and ‘business as usual’ scenarios described inChapter 2.2. The results are presented in Table 2.

National demand for aggregates has been assumed to beeffectively constant across the period to 2020, in line withODPM guidance (ODPM, 2002b). The arisings of recycledand secondary aggregates are assumed to increase at aslow rate over the period to 2010 and 2020 in line withpopulation estimates for Hampshire, Portsmouth andSouthampton (ONS, 2003) except where specificinformation was available. An average increase of 2.5%was chosen for both the periods 2004 to 2010 and 2010 to2020. Details of the calculations are given in Sowerby et al.(2005). Based on these estimates, the proportion ofrecycled and secondary aggregates used in Hampshirecould rise to 19.6% by 2010 and 21.6% by 2020 under the‘stretching best practice’ scenario.

8

The largest source of recycled aggregates remains theprocessing of inert CD&EW. Under the stretching bestpractice scenario, this would rise from the current level ofabout 66% of the potentially recyclable material to 95% by2020. Estimates were also made of the amount that couldbe used in higher value applications (concrete, asphalt).This is currently effectively zero, but it estimated that 10%(65,400 tonnes) of the recycled aggregates from thissource could be used in higher value applications by 2010and 20% (150,000 tonnes) by 2020.

For highway maintenance arisings, it is estimated that arapid increase in recycling up to about 100,000 tonnes perannum could take place by 2010, building on initiativesthat have already begun under the PSA and partnershipwith Raynesway Construction Southern and FosterYeoman. This is considered to be about the maximum thatcan be achieved, and a slow growth in line with populationis predicted from 2010 to 2020.

The arisings of spent railway ballast are thought likely toremain relatively constant to 2020. This is all currentlyrecycled, approximately 90,000 tonnes (64%) as unboundgranular fill and 50,000 tonnes (36%) as capping.Potentially some of this material could be used as aggregatein concrete and asphalt, and more could be used as sub-baseand less as general fill. The stretching best practice estimatestherefore predict 10,000 tonnes (7%) in bound applicationsby 2010, rising to 25,000 tonnes (18%) by 2020, with theamount used as sub-base rising to 90,000 tonnes (64%) by2010 and then remaining constant to 2020. The amount usedas general fill will decrease proportionately.

At the time of the survey, only one Energy from Wasteplant was operational, at Chineham near Basingstoke. Theother two plants, at Marchwood and Portsmouth, should beoperational by the end of 2005. When all three plants areoperational they will generate about 100,000 tonnes ofincinerator bottom ash per annum. It is considered thatabout 90,000 tonnes (90%) will be suitable for processingto form incinerator bottom ash aggregate. This represents avaluable source of aggregate for Hampshire. It is likelythat this will be used almost entirely in bound form,principally as coarse aggregate in asphalt or blocks, toavoid any concerns about environmental risks if it wasused as unbound granular fill.

Some allowance has been made for the use of recycledglass, plastic and tyres as aggregates or as substitutes foraggregates in the period to 2020. Expansion of collectionschemes for glass, including flat glass, will result in morematerial becoming available, and some use in asphalt or asbedding sand is likely, particularly in urban SouthHampshire. Recycled tyres may be used as rubber inasphalt, as aggregate in concrete, or as tyre bales in avariety of applications (Hylands and Shulman, 2003).Plastics are probably least likely to be used as aggregates.

3.3 Actions required to achieve the ‘stretching bestpractice’ scenario targets

The ‘stretching best practice’ scenario implies that changeshave to be made to existing practices to achieve the targetsin Table 2. The increase in recycling under the ‘business asusual’ scenario is much smaller and will not enable

Table 2 Estimates of future use of recycled and secondary materials as aggregates in Hampshire

Estimated amount Estimated amount Estimated amountrecycled in 2004 recycled in 2010 recycled in 2020

Material (tonnes per year) Scenario (tonnes per year) (tonnes per year)

Recycled aggregates (from inert CD&EW) 500,000 Stretching best practice 654,000 750,000Business as usual 525,000 550,000

Highway new works and maintenance 45,000 Stretching best practice 100,000 102,000Business as usual 47,500 50,000

Railway ballast 140,000 Stretching best practice 140,000 140,000Business as usual 140,000 140,000

Incinerator bottom ash aggregate 1,000 Stretching best practice 90,000 90,000Business as usual 2,000 5,000

Recycled glass 0 Stretching best practice 15,000 15,400Business as usual 0 0

Recycled plastic 0 Stretching best practice 1,000 2,000Business as usual 0 0

Recycled tyres 0 Stretching best practice 5,000 5,130Business as usual 0 0

Totals 686,000 Stretching best practice 1,005,000 1,104,530Business as usual 714,500 745,000

Total aggregate use in Hampshire 5,119,500 Zero growth in total aggregate use assumed 5,119,500 5,119,500

Proportion of recycled and secondary aggregates 13.4% Stretching best practice 19.6% 21.6%Business as usual 14.0% 14.6%

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Hampshire to meet its goals under the MRS. The overallphilosophy is set out in ‘More from Less’ (HampshireCounty Council, 2005). The particular changes and actionsthat are required to achieve the targets for recycled andsecondary aggregates are discussed here.

3.3.1 Infrastructure

The proposed increase in recycled aggregates will requirethe development of additional CD&EW Recycling Centresto produce the material. The current distribution ofCD&EW Recycling Centres shows them mainly aroundthe periphery of the Southampton–Portsmouth andAldershot areas (Figure 1). Several areas appear underprovided in relation to their population, such asBasingstoke, Andover and Winchester, though there arewaste transfer stations in these areas that collect CD&EWand send it on to CD&EW Recycling Centres elsewhere.New CD&EW Recycling Centres will have to meet strictrequirements on control of noise, dust, vibration, trafficand visual impact. They will also have to operateaccording to quality control protocols if they are toproduce aggregates that are acceptable under modernspecifications. CD&EW Recycling Centres should belocated close to where the material arises and to theproposed market, in accordance with the proximityprinciple. Excessive transport distances will also make thematerials uneconomic in relation to primary aggregates.

There will also be a requirement for a site to enable theincinerator bottom ash from the three incinerators inHampshire to be weathered and processed into aggregate.This should ideally be located centrally to the incinerators,

so that the product would be available to all parts of thecounty without excessive transport distances. The sitewould need to be at least 4 ha in size and would need tohave arrangements to contain the drainage water from theIBAA during the weathering phase. This would form partof a strategic network of recycling centres for Hampshire.This is discussed in more detail in Chapter 5.3.

3.3.2 Market developmentThere is need for market development in several areas,particularly for the use of recycled and secondaryaggregates in bound applications. The use of thesematerials can be encouraged by the use of targets incontracts and planning controls, but the most productiveapproach is likely to be the development of partnershipssuch as the existing one for highway maintenance, whereall parties can feel ownership of the project and worktowards common goals. This arrangement could usefullybe extended to other areas.

A tool that can be used by the planning system toincrease the amount of recycling in redevelopment projectsis the Demolition Protocol (EnviroCentre, 2004). Underthe protocol, a pre-demolition audit is carried out and thequantity of material that can be recycled is calculated; thisis called the Demolition Recovery Index (DRI). It appliesnot only to aggregates, but also to other recyclablematerials such as metal, glass, plasterboard, timber andornamental stone. These quantities are then carriedforward into the design of the new development as theNew Build Recovery Index (NBRI) and are itemised in theBill of Quantities. The material does not have to be

CD&EW Recycling Centres

Figure 1 Location of CD&EW Recycling Centres in Hampshire

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recycled on site; it can be sent to recycling centres at thetime of demolition and replaced by equivalent quantities ofrecycled materials when the new structure is built. Thisdoes not put undue limitations on the developer in terms ofthe type of new structure or the timescale forredevelopment, but ensures a high level of recycledcontent in the new development. The protocol is intendedto be used as part of the planning process, with its usebeing one of the conditions of planning permission for thenew development.

Another factor that will encourage greater recycling isthe Code for Sustainable Building, which is expected to belaunched by the UK Government (DTI) in 2006. It is likelythat this will include a minimum value for recycledmaterial content in new projects, possibly 10% of thematerial value. This will only apply for projects above acertain value, but the level has not been decided. Use ofrecycled aggregates is one way in which developers canrapidly increase the recycled content of their projects,particularly by their use in concrete blocks and structuralconcrete which are high value products. They can also beused in pipe bedding and backfill, general oversite, fillbelow floor slabs and in access roads.

Education is a major requirement if the targets forRecycled and Secondary Aggregates use are to be met.This is partly a case of dissemination of information aboutspecifications, quality control, regulations and what ispossible with the materials, and partly making the businesscase for recycling. There is a need to target all sectors ofthe construction industry and the public with appropriatemessages. Some of these may be best done on a nationalbasis, but local initiatives will also be important.

3.3.3 Standards and specificationsStandards and specifications are not a barrier. Mostnational specifications have been updated in recent yearsto allow the use of recycled and secondary aggregates (seeTable 3) and a protocol has been developed to ensurequality control. The problem is more often one ofperception. People may equate the mixed rubble in abuilder’s skip with recycled aggregates, or may beworking to outdated specifications that did not permit theuse of recycled or secondary aggregates. There may alsobe environmental concerns about the use of somematerials, such as incinerator bottom ash aggregate,especially in a county like Hampshire large parts of whichare underlain by a major aquifer. Hence a programme ofeducation is required, and one of the best ways of doingthis is by demonstration projects that illustrate what can beachieved and the environmental and economic benefitsthat can be realised. This theme is taken up in Chapter 4.

Another common perception is that recycled andsecondary aggregates will be more expensive than primaryaggregates. The reverse is more often the case, as thedemonstration projects illustrate.

There is considerable potential for increasing both theamount of recycled and secondary aggregates used inHampshire and the value of the applications for which theyare used. The targets should not be regarded as preciseestimates but as goals to aim for, which should be reviewed

Table 3 Specifications and standards that permit theuse of recycled and secondary aggregates

! Specification for Highway Works (SHW), updatedquarterly:

– Pipe bedding and filter material.

– Earthworks (general and selected granular fill,capping, etc).

– Unbound sub-base.

– Cement and other hydraulically bound materials.

– Asphalt base and binder course.

– Pavement quality concrete.

! HD 35/04 Conservation and the use of secondary andrecycled materials, 2004:

– Updated from original version of 1995.

– Volume 7 Part 1 Section 2 of the Design Manual forRoads and Bridges.

– Includes new materials including recycled glass andincinerator bottom ash.

– Extends potential use of materials beyond the currentSHW.

! BS 8500: Concrete 2002:

– Defines recycled aggregate (RA) and recycledconcrete aggregate (RCA).

– Permits their use in various grades of concrete and inmixtures with primary aggregates.

– Permits use of blast furnace slag.

! Specification for the Reinstatement of Openings inHighways, 2nd edition 2002:

– Permits use of recycled and secondary aggregates.

– Provided meet defined performance characteristics.

– Local authority approval needed.

! Civil Engineering Specification for the Water Industry,6th edition 2004:

– Extends use of recycled aggregates.

! European harmonised standards for aggregates, 2004:

– Do not differentiate between primary, recycled andmanufactured aggregates.

– Have to be called up by national specifications.

! WRAP quality protocol for the production of recycledaggregates from inert waste:

– Framework document for producers of recycledaggregates.

– Quality control plan to meet specificationrequirements.

– If followed, demonstrates wastes have been fullyrecovered.

– Called up by the Specification for Highway Works.

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! Demonstration Project 3: Recycled Surface DressingSweepings.

! Demonstration Project 4: Bar End Household WasteRecycling Centre.

! Demonstration Project 5: A3 Bus Priority Corridor,Portsmouth to Clanfield.

! Demonstration Project 6: North Popley Development,Basingstoke.

The projects were chosen to give a good geographicspread across the county and represent the main areas ofhighway and infrastructure construction and maintenancewhere recycled and secondary aggregates can readily beused in Hampshire. Hampshire County Council was theclient for all the projects, but they cover a wide range ofsituations and a number of different departments wereinvolved.

4.1.1 Demonstration Project 1: Embankment stabilisationon the A325 at Alice Holt

This project was a major maintenance scheme contractedout from Hampshire County Council (HCC). The projectwas a three phase operation with RCS being involved inphase two, which involved the stabilisation of the A325near Alice Holt, over a distance of about 1.8km. The worksare shown schematically on Figure 3. The embankmentwas made up of poor quality clay at a variable slope andhad been suffering from instability. The excavated materialwas replaced with Class 6F5 selected granular fill. Theembankment ranged from 0.8m to 5.0m in height and theworks required a total of 29,000 tonnes of imported fill.

periodically. Recycling should not be seen as an end in itselfbut as part of the overall process of developing a moresustainable construction industry, which will benefitindustry and the general public. This is exemplified by theMRS process carried out by Hampshire County Council andthe City Councils of Portsmouth and Southampton.

4 Use of recycled and secondaryaggregates in Hampshire:demonstration projects

4.1 Demonstration projects

The use of recycled and secondary aggregates has becomemuch more widespread in recent years and applicationshave been described from a wide range of constructionscenarios; see Reid and Chandler (2001) or the numerouscase studies on the AggRegain web site(www.aggregain.org.uk). As part of this project, a total ofsix demonstration projects were developed over the periodJuly 2004 to June 2005. The projects are described brieflybelow, summary versions are given in Appendix A and thefull case studies in Appendix B. The main points aresummarised in Table 4, and the locations of the projectsare shown in Figure 2. The case studies were numberedand are listed below:

! Demonstration Project 1: Embankment Stabilisation onA325 at Alice Holt.

! Demonstration Project 2: Recycled Asphalt in FootwayWorks on B3047 at Martyr Worthy.

Table 4 Summary table for demonstration projects

No. Title ApproximateActivity Applications Materials amount used

1 Embankment Stabilisation on A325 at Alice HoltEarthworks. Selected granular fill. Recycled aggregate. 29,000 tonnes

2 Recycled Asphalt in Footway Works, B3047 at Martyr WorthyFootways. Cold recycled bitumen bound material. Recycled asphalt. 300 tonnes

3 Recycled Surface Dressing Sweepings at sites across HampshireSurface dressing. Reuse of surplus surface dressing material. Recycled asphalt. 4,000 tonnes

4 Bar End Household Waste Recycling CentreAccess road. General granular fill. Recycled aggregate. 12,000 tonnesFootway. Selected granular fill. Recycled asphalt.Concrete base slab. Capping. Recycled railway ballast.Retaining walls. Unbound sub-base. Incinerator bottom ash aggregate.

Cold recycled bitumen bound material.Structural concrete.

5 A3 Bus Priority Corridor, Portsmouth to ClanfieldRoad widening and reconstruction. General granular fill. Recycled asphalt. 4,000 tonnes

Lower trench fill. Recycled concrete (crushed kerbs).Capping. Subsoil and topsoil.Unbound sub-base.

6 North Popley Development, BasingstokeAccess road for new school on General granular fill. Chalk. 2,600 tonnesgreenfield site. Cement bound sub-base and trench backfill. Recycled asphalt.

Cold recycled bitumen bound material.

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The new embankment was built at a uniform slope of 1:3.The imported fill was supplied by recycled aggregatesderived from processing construction and demolitionmaterial from Day Aggregates Ltd, TJ Transport fromSelborne, and Wessex Construction Ltd (sited in Adsdean,Sussex), thus avoiding the use of primary aggregates.

4.1.2 Demonstration Project 2: Recycled asphalt infootway works, B3047 at Martyr Worthy

This case study dealt with the use of cold recycled bitumenbound material in routine highway maintenance works,with a particular focus on one example of innovative use

of the material in a footway renovation project. Theparticular form of cold recycled bitumen bound materialused involved the use of foamed bitumen as the mainbinder, usually with asphalt planings from other highwayworks as the coarse aggregate. Foster Yeoman set up amobile plant at their depot at Micheldever to produce thismaterial (commonly known as ‘Foamix®’) and it has beenwidely used across the county. Use of a single layer ofFoamix® can replace separate layers of sub-base and basein road construction (Figure 4), resulting in a thinnerpavement. The cold recycling technique also saves energyand emissions of CO

2 compared to conventional hot

New 1:3 slope being constructed

Existing soft clay fill

removed

Steps dug out from existing embankment

ROAD

Existing slope

Backfill of 6F5 material

Embankment height varies from 0.8m to 5m high

Note: The surface dressing projectwas carried out at a number ofsites across Hampshire; these arenot shown on the map.

Figure 2 Locations of demonstration projects

Figure 3 Cross section of embankment works at Alice Holt

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asphalt. In the particular example featured in the casestudy, cold recycled bitumen bound material was used torepair sub-base and as combined base and binder course inthe renovation of some 700 m of footway. The use of thismaterial meant that only a surface dressing was requiredon top, instead of a full surface course as would have beenrequired under a conventional reinstatement.

4.1.3 Demonstration Project 3: Recycled surface dressingsweepings at sites across Hampshire

In surface dressing operations on highways, there are alwayssome surplus unused materials. After the surface dressinghas been laid, further surplus material is generated assweepings of loose material from the road surface. InHampshire there are a number of remote sites where unusedsurface dressing chippings have been stockpiled for anumber of years. These sites are now receiving post surfacedressing sweepings as well as the unused material. Thesurface dressing sweepings would previously have been sentto landfill or used on farm tracks. In 2003 these stockpileswere estimated to be in excess of 4,000 tonnes. HampshireCounty Council and their surfacing contractor RoadMaintenance Service Ltd (RMS) wanted to find a use for theexcess surface dressing chippings and sweepings. Thematerial was dry screened, lightly coated with bitumen andused in new surface dressing operations. About 4,000 tonneswas successfully laid between May and August 2004. Thematerial has been monitored and performance has been verysatisfactory. This has saved the import of primaryaggregates and also resulted in significant cost savings.

4.1.4 Demonstration Project 4: Bar End HouseholdWaste Recycling Centre (HWRC)

This was a capital project undertaken for the WasteManagement Group of Hampshire County Council to builda new household waste recycling centre (HWRC) to servethe Winchester area. The project involved upgrading ofsome 300 m of access road to the site, construction of abase slab for the containers for recycled waste, retainingwalls and a one-way road system round the slab, togetherwith associated drainage and landscaping works.Sustainability was built into the design from the start, withmaximum use of recycled aggregates and asphalt from

existing buildings, access road and car park on the site. Asustainable urban drainage system (SUDS) was included inthe design. Where additional aggregates were required,they were supplied by recycled aggregates and spentrailway ballast from the local area. The base slab for theHWRC included recycled aggregate as 15% of the coarseaggregate. Cold recycled bitumen bound material from theFoster Yeoman plant at Micheldever was used for the baseand binder course of the access road and perimeter roadround the slab. The coarse aggregate was incineratorbottom ash aggregate from the Energy from Waste plant atChineham. A cross section of the access road is shown onFigure 5, showing the use of recycled and secondaryaggregates. The use of all the recycled and secondaryaggregates was successful, and the project is intended to bean example of how sustainability can be maximised infuture projects for this type of facility.

4.1.5 Demonstration Project 5: A3 Bus Priority Corridor,Portsmouth to Clanfield

The A3 Bus Priority Corridor Project is included inHampshire County Council’s (HCC) Local Transport Plan2001-6. It is managed under a partnership between HCC,Portsmouth City Council (PCC), Havant Borough Council(HBC), East Hampshire District Council (EHDC) and thebus operator First. It will provide high quality, reliablepublic transport by offering passengers a priority busservice along the A3 corridor from Gunwharf Quays,Portsmouth to Clanfield, a village north of Horndean. Theworks affect a 12km long stretch of road and involve roadwidening, carriageway and footway reconditioning,diversion of statutory undertakers utilities, drainage,replacement street lighting and new/upgraded pedestriancrossings (puffins and toucans). To ensure the project isdelivered in a sustainable way a best practice checklistwith supporting tools is under development. Currently onlybeing used in-house on a few trial schemes, the checklistand tools are intended to be cascaded to other sections inthe Environment Department at HCC. Specific aspectsinvolving recycling include the use of recycled asphaltplanings and crushed concrete kerbs as capping and sub-base for the widened road and new footways andexcavated subsoil as general fill and landscaping.

Normal Classified road Classified road using Foamix

40mm surface course

60mm binder

40mm surface course

60mm binder

150mm road base210mm Foamix

200mm sub-base

Figure 4 The layers found in a normal classified road and a classified road using Foamix®

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4.1.6 Demonstration Project 6: North Popleydevelopment, Basingstoke

North Popley is a major new mixed use development on agreen field site on the north side of Basingstoke. The site isowned by Hampshire County Council (HCC), who carriedout preliminary infrastructure works to provide a spine roadand services across the site. Preliminary works includedprovision of a 250 m access road for a new school. Inaccordance with HCC’s corporate policies on sustainability,opportunities were sought to maximise recycling and the useof recycled and secondary aggregates in the construction.Any methods that were shown to work successfully could beextended to the much larger spine road and associatedworks. Two main techniques were used:

! Cement stabilisation of in situ chalk to form a cementbound sub-base.

! Cold recycled bitumen bound material as the base forthe road pavement.

HCCs specification was revised to include clauses oncement stabilisation and cold recycling, in particular totake advantage of new developments described in therecently published TRL Report TRL611 (Merrill et al.,2004). The cold recycled bitumen bound material usedfoamed bitumen as the binder and recycled asphalt fromthe A325 Alice Holt project as the coarse aggregate. It wassupplied by Foster Yeoman from the plant at Micheldever.The project was very successful and resulted in over 2,000tonnes of chalk being reused on site in a variety ofapplications, plus the use of about 600 tonnes of recycledasphalt in the cold recycled road pavement.

4.2 Factors influencing the use of recycled andsecondary aggregates in the demonstration projects

The demonstration projects illustrate how recycling andthe use of recycled and secondary aggregates can be

maximised in highway maintenance and new constructionworks. A number of factors are critical for the success ofthis in Hampshire:

! There has to be a clear lead and commitment from theclient. In this case it arises from Hampshire CountyCouncil’s corporate objectives, which include an aim toprotect the environment through the promotion of theprinciples of environmental sustainability. This has beenworked through in the context of highway maintenanceand drives the day-to-day activities in the county.

! There has to be early involvement of all the keystakeholders, including contractors and suppliers.Hampshire County Council has enabled this through thepartnership it has set up with Raynesway ConstructionSouthern and Foster Yeoman for highway maintenance.However, it is possible to achieve this early input underother contractual arrangements.

! All parties have to be fully committed to the project andwork as a team sharing common goals. In thisenvironment innovation can flourish and new methodsand materials can be developed and trialed.

! Logistical arrangements have to be made and facilitiesprovided to enable arisings to be processed and reusedin the highest value applications. In Hampshire, thisinvolved setting up two segregation plants for highwayarisings, establishing relationships with a recyclingcontractor and establishing a cold recycling plant.

! Opportunities should be sought to take advantage oflocally available recycled and secondary aggregates. InHampshire this involved use of recycled aggregates,recycled asphalt and spent railway ballast and exploringthe potential of a large material stream of incineratorbottom ash aggregate.

! Most applications involving recycling and the use ofrecycled and secondary aggregates are already covered

Surface course45mm

Sub-base(recycled aggregates)

150mm

Capping ~200mm

Foamix baseand binder

course70-300mm

SUDS

Rain

Water table0.9m-2.9m

below ground level

Existing roadstructure

160mmFoamix

FootpathKerbandgully

Figure 5 Cross section of access road to Bar End Household Waste Recycling Centre

15

by the UK Specification for Highway Works and designguides such as TRL Report TRL611 (Merrill et al.,2004). However, to take advantage of locally availablematerials it may be necessary to develop new methodsand specifications, such as for the use of incineratorbottom ash aggregate in the base and binder course atBar End and cement stabilisation at North Popley.

The projects had an emphasis on sustainability in anumber of ways, not just in the use of recycled andsecondary aggregates. Examples of this include theprovision of a sustainable drainage system at Bar End andthe use of a long-life surface dressing on the A3 BusPriority Corridor.

The demonstration projects also show the use ofinnovative plant, such as a quiet kerb crusher on the A3Bus Priority Corridor and the cold recycled bitumen boundmaterial mixing plant at Micheldever, which supplied coldrecycled bitumen bound material for the Martyr Worthy,Bar End and North Popley sites. Innovative designmethods included the use of the recently published TRLReport TRL611 (Merrill et al., 2004), the development ofa method statement for the use of incinerator bottom ashaggregate in cold recycled bitumen bound material and theuse of cold recycled bitumen bound material in footwayswith only a surface dressing rather than a full surfacecourse. Hampshire County Council adapted theirspecification to enable the use of TRL611 and the use ofcement stabilisation of chalk at North Popley. Material UseSheets are being introduced on projects to allow linking ofsurplus materials from one site to another and reduce theneed for primary aggregates.

The demonstration projects cover a wide range ofapplications and materials, but they do not cover all theuses of recycled and secondary aggregates that arepossible. Other applications could include:

! Processing and reuse of materials on demolition andredevelopment sites.

! Use of recycled aggregate and recycled concreteaggregate in concrete.

! Use of recycled aggregates and incinerator bottom ashaggregate in block manufacture.

! Use of recycled aggregate in concrete haunch repairs.

! Use of recycled asphalt in new hot asphalt materials.

! Use of recycled glass in asphalt base and binder courses.

! Use of recycled glass as bedding sand for pavers andpipes.

! Use of tyre bales in roads over soft ground or flooddefence applications.

! Import of china clay sand for fill, pipe and paverbedding and concrete.

Achieving the routine use of recycled and secondaryaggregates in these applications as well as those illustratedby the demonstration projects, will be key to reaching thetargets set for 2010 and 2020 under the ‘stretching bestpractice’ scenario.

4.3 Benefits from the use of recycled and secondaryaggregates in the demonstration projects

The recycled and secondary aggregates in thedemonstration projects performed as well as equivalentprimary aggregates, so there was no technical disbenefitfrom their use. In a number of cases there were significantbenefits, as it enabled the use of material generated on sitethat might otherwise have gone to landfill, such as thechalk arisings at North Popley. Reduced thicknesses ofpavement layers can be achieved by the use of coldrecycled bitumen bound material and stabilisation withcement and other materials. Significant cost savings canalso be made by the use of recycled and secondaryaggregates. The reuse of recycled surface dressingsweepings is estimated to have led to cost savings of over£28,000. There are also significant environmental benefits:

! Reduced consumption of primary aggregates.

! Reduced disposal of material to landfill.

! Reduced haulage and associated fuel use.

! Reduced energy use and CO2 emissions by the use of

cold recycled bitumen bound material rather than hotasphalt.

The demonstration projects also made a significantcontribution towards Hampshire’s PSA targets.

County councils are particularly well placed to driveincreased recycling because the scale of their operations issufficiently large to give them the opportunities to pursuethese options and to justify the initial effort needed to setup the systems to make the approach work in practice. Inthis respect Hampshire is an exemplar local authority, andthe approach Hampshire has adopted could usefully befollowed by other local authorities in similar positions. Theeffort that has been put in has more than amply beenrepaid by cost savings and visible improvements in thesustainability of its highway operations, which in turnreflects the concerns of residents and government for amore sustainable future.

5 Planning: minerals and wastedevelopment framework

5.1 Principles

The principles set out in ‘More from Less’ are being takenforward in a number of ways by Hampshire County Council,Portsmouth and Southampton City Councils, Project Integraand the Hampshire Natural Resources Initiative. One of theseis the statutory Hampshire Minerals and Waste DevelopmentFramework. The core planning strategy document(Hampshire County Council, 2005) for this was published forconsultation at the end of September 2005.

The strategy builds on the work described in this reportin a number of ways. It is based on the overall vision of‘More from Less’ that

‘We will change the way we use material resources tomaximise efficiency and minimise wastage.’

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Demonstration Project 1: Compacting recycled aggregates as embankment fill at Alice Holt

Demonstration Project 2: Footway at Martyr Worthy with surface dressing over cold recycled bitumen bound base

17

Demonstration Project 3: Screening surface dressing chippings for reuse

Demonstration Project 3: Rural road with recycled surface dressing

18

Demonstration Project 4: Recycled aggregate sub-base in access road to Bar End Household Waste Recycling Centre

Demonstration Project 4: Cold recycled bitumen bound base with incinerator bottom ashaggregate over recycled aggregate sub-base, Bar End Household Waste Recycling Centre

19

Demonstration Project 6: Chalk stabilised with cement in situ as sub-base for access road to newschool, North Popley Development. Bituminous tack coat applied to project stabilised material

Demonstration Project 6: Cold recycled bitumen bound base being placed and compacted, North Popley Development

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This vision has three key elements relevant to the Plan:

! Changing behaviour.

! Resource efficiency.

! Minimising waste.

The preferred option developed from this visionincludes, among other outcomes:

! An overall recycling rate of 60% by 2020.

! Materials and energy recovery maximised fromunavoidable waste.

! Use of landfill for all waste materials reduced to aminimum practicable level by 2020.

! Demand for new minerals reduced to minimumpracticable levels, with extraction of land-won sand andgravel reduced as far as practicable.

! New sites and facilities provided to meet needs in asustainable efficient way.

! A supportive policy framework and all sectors of thecommunity involved in delivering solutions and change.

5.2 Policies

The strategy recognises that fundamental changes toexisting practices and attitudes are required in order tomeet the targets and achieve the vision. This includessuggestions that the following sustainable design elementsshould be reflected in city, district and borough councils’Local Development Frameworks:

! Using recycled or secondary materials in builtdevelopment as far as possible, especially in associatedroad building and hard surfacing.

! Where demolition needs to take place beforeconstruction, recovering or recycling the demolitionwaste as far as possible, preferably on-site.

The North Popley demonstration project gives anexample of how the first objective can be achieved, andthe Demolition Protocol and forthcoming Code forSustainable Building will be useful tools to help achievethe second.

The strategy includes an overall recycling target of 60%for all waste by 2020, with specific targets for CD&EW of50% for 2010 and 60% for 2020. The figures quoted inChapter 3 indicate that in 2004 about 33% of all CD&EWwas recycled as aggregate. Estimates under the ‘stretchingbest practice’ scenario for recycling as aggregate wereabout 40% by 2010 and 50% by 2020, this being themaximum that is thought to be recyclable in this way.Achieving the overall recycling rate of 60% will thereforerequire recycling of other fractions of the CD&EW. Thiscan be achieved by recycling excavation waste and othermaterials as soil, mixed with green waste compost, and byrecovering other components of the waste stream such astimber, plasterboard, metal, glass and plastic.

5.3 Provision of recycling capacity

Recycled and secondary materials require processing beforethey can be used as aggregates, and the provision of adequatefacilities is essential if the targets for recycled and secondary

aggregate use are to be met. Such facilities should be locatedso as to minimise the transport distances from where thematerials arise and where they are to be used; these will notnecessarily be the same, particularly with the development ofseveral large areas of new housing on greenfield land. Thesedevelopments offer many opportunities for the use ofrecycled and secondary aggregates.

Long term development in Hampshire is to be met bylarge scale Major Development Areas (MDAs) in fourareas: Waterlooville, Eastleigh, Basingstoke and Andover.The development areas are shown in Figure 6. Thesedevelopments will incorporate housing, roads, andindustrial and commercial development. In addition, largeareas of MoD land in the Aldershot/Farnborough area arelikely to be released for development in the near future.

The MDAs provide particular opportunities for the useof recycled and secondary aggregates as they are to bedeveloped according to sustainability principles. However,most CD&EW arises from the older urban areas ofPortsmouth and Southampton, as shown by the location ofexisting recycling centres on Figure 1.

The strategy states that siting issues have to be addressedfor facilities for an additional 750,000 tonnes per year ofstrategic CD&EW recycling. Appropriate regionaldistribution is necessary, so that the recycled aggregates areavailable where they will be needed, not just in some partsof the county. A separate table gives a breakdown ofindicative recycling capacity requirements for Hampshire,with the county split into three sub-county areas:

! Urban South Hampshire (including Portsmouth andSouthampton).

! Forest and downland.

! Hampshire’s part of the western corridor (northHampshire including Basingstoke).

The bulk of the recycling capacity is indicated for UrbanSouth Hampshire. Indicative capacities are given for 2010,2015 and 2020. The overall indicative capacity for 2020 isa little over twice the target figure of an additional 750,000tonnes per year.

The strategy also recognises the need for facilities andcapacity for 90,000 tonnes of incinerator bottom ashrecycling, in line with the estimates for the amount of thismaterial that will be available for recycling as aggregate inTable 2. Provision is also made for a ‘soil hospital’ to treat35,000 tonnes of contaminated soil; at least some of thetreated material would potentially be available to use asrecycled aggregates.

The strategy does not identify particular sites for therecycling facilities, but lists criteria that should be appliedwhen deciding on the suitability of individual sites,including the proximity principle and closeness to theStrategic Transport Network. Co-location of recyclingfacilities with other related activities, such as ResourceRecovery Parks, is suggested as a way of identifyingsuitable sites. It is suggested that there should be severallarge strategic facilities for producing recycled aggregatesfrom CD&EW to the standards required by the constructionindustry, with several smaller scale facilities such as skipwaste transfer and recycling stations. It is suggested that the

21

incinerator bottom ash recycling plant should be close to theMarchwood and Portsmouth facilities, as these producemore ash, offer connection to sustainable transport optionssuch as rail, and be within 0.5 km of the road networklinking the three plants. The soil hospital should be locatedin Urban South Hampshire, since this is where thecontaminated soils predominantly arise.

An important point that emerged during the MRSprocess was the need for permanent planning permissionfor CD&EW recycling facilities in order to attractsufficient investment from operators to install equipmentto process materials to the standards required for highvalue applications. Often planning permissions for suchsites are given on a temporary basis and are a disincentiveto investment. The strategy recognises the need to addressthis issue. This is essential if the stretching best practicetargets are to be met.

The strategy also provides for safeguarding the existingwharves and rail depots that are used for importingaggregates into Hampshire.

5.4 Supply of minerals

The strategy quotes the South East Plan which sets out therequirements for planning for minerals as follows:

‘The supply of construction aggregates in the South Eastshould be met from a significant increase in supplies ofsecondary and recycled materials, a reduced contributionfrom primary land-won resources and an increase inimports of marine-dredged aggregates.’

The South East Plan provides a sub-regionalapportionment of 2.63 million tonnes per annum (mtpa) of

land-won sand and gravel for Hampshire, Portsmouth andSouthampton. This is higher than the current level of about2.19 mtpa (Table 1). According to the strategy, the supplyof land-won aggregate has shown a generally decreasingtrend over the last decade despite increased economicgrowth. Although there has been a small increase frommarine sources, the general trend in aggregate supply hasbeen static.

It is proposed to limit the amount of land-won sand andgravel by increased use of recycled and secondaryaggregates. However, there are limitations to this. In mostof the applications where recycled and secondaryaggregates are used at present, they are substituting forcrushed rock rather than sand and gravel, so the effect ondemand for sand and gravel is limited. Sand is inparticularly short supply in Hampshire, but most recycledand secondary aggregates are relatively coarse grained,and do not directly substitute for natural sand.

At present (Table 2) recycled and secondary aggregatesare thought to account for only about 13% of theaggregates used in Hampshire, and even under the‘stretching best practice’ scenario that only rises to about22% by 2020. Recycled and secondary aggregates cannotcompletely replace primary aggregates. However, everyeffort should be made to increase the extent to which theyare used, especially to increase their use in high valueapplications such as concrete, where they would directlyreplace sand and gravel.

At present there is no sub-regional apportionment forrecycled and secondary aggregates. However, there is aregional apportionment of 118 million tonnes for the SouthEast to cover the period 2001 - 2016. Assuming this is

Figure 6 Proposed major development areas

Development area

22

apportioned sub-regionally by population, this wouldequate to a target of about 1.5 mtpa for Hampshire. Thiscompares to present levels of about 0.69 mtpa andstretching best practice targets of 1.0 mtpa by 2010 and1.1 mtpa by 2020 (Table 2). There is considerableuncertainty about all figures connected with recycled andsecondary aggregates, but the discrepancy is too large tobe explained purely by statistical uncertainty. It may bepartly explained by the lack of information on materialrecycled on site during redevelopment. However, ifincreased use of recycled and secondary aggregates is tobe relied on then the reasons for the discrepancy should beinvestigated.

A further complication is that to date there has been norequirement for producers of recycled aggregate to record thequantities of materials they have sold, unlike primaryaggregates. It is therefore very difficult to get accurate figures.This could make it difficult to tell whether targets for recycledand secondary aggregate use are being met. In the presentproject, estimates of amounts recycled were made fromreturns from operators of licensed waste managementfacilities to the Environment Agency; these were difficult tointerpret, and were not designed to record recycling. Newrequirements for operators of exempt sites were introducedfrom July 2005, which should make it easier to obtain data onthe amounts of material that are proposed to be recycled ordeposited on these sites, but collating the information is likelyto be a labour-intensive task.

5.5 Conclusion

The strategy addresses the issues that are relevant if theproposed increases in recycled and secondary aggregateuse are to be achieved. Further work will be required insome areas. The MRS has worked by getting all thestakeholders involved in the process and discussing theissues openly. If this approach is continued, it is likely thatmost of the obstacles can be overcome.

6 Issues, guidance and actions: Recyclingin transport infrastructure revisited

In October 2001, TRL published ‘Recycling in transportinfrastructure’ (Reid and Chandler, 2001), a guidancedocument on increasing the amount of recycling and use ofalternative materials in transport infrastructure renewalworks. The publication was the result of an extensivereview of the topic by TRL, supported by a steering groupwith cross-industry representation. The report identifiedthe main issues, summarised guidance that was alreadyavailable and recommended actions for the main groups ofstakeholders. The conclusions were summarised in a table,reproduced here as Table 5. It is instructive to look at theseissues and recommended actions in the context of thepresent project, to see what progress has been made andwhether any other issues have emerged as significant inrecycling in construction. An updated version of thesummary table is included as Table 6.

6.1 Issues

Ten areas where there were potential obstacles to the useof recycled and secondary aggregates were identified. Theissues, available guidance and recommended actions arereviewed briefly below.

6.1.1 SpecificationsAt the time of ‘Recycling in transport infrastructure’, theMay 2001 amendments to the Specification for HighwayWorks had just been issued. These greatly extended thescope for use of recycled and secondary aggregates andrecycling techniques, but a number of other specificationsstill excluded them. Since then, most of thesespecifications have been updated (Table 3) and it is nowpossible to use most commonly available materials in mostapplications, provided they meet the requirements forengineering properties. Specifications are thus not a barrierto the use of recycled and secondary aggregates, providedup-to-date specifications are used.

6.1.2 Test methodsThe same test methods were being used for primary,recycled and secondary aggregates, although researchshowed that some of the test methods for primaryaggregates were not appropriate for some recycled andsecondary aggregates. This remains the case; harmonisedEuropean Standards for aggregates, introduced in the UKin 2004, cover all aggregates, whatever their origin, andrequire the same tests to be carried out on them. Theadvantages this has in placing recycled and secondaryaggregates on the same level as primary aggregatesoutweighs any disadvantages in applying inappropriate testmethods to a small number of materials. Work is underwayin Europe towards producing bespoke test methods forrecycled and secondary aggregates, particularly throughthe collaborative European research project SAMARIS(Sustainable and Advanced Materials for RoadInfraStructure). Information on SAMARIS can be obtainedfrom the web site www.samaris.zag.si.

‘Recycling in transport infrastructure’ alsorecommended that more performance-based test methodsand specifications be developed. These take the focusaway from the origin of a material and focus on itsperformance. Work has continued on development ofperformance-based test methods and specifications in theUK, Europe and elsewhere (Merrill et al., 2004; Nunn,2004), but implementation on a large scale is likely to beseveral years ahead.

Overall, test methods only provide a small barrier toparticular uses of a few materials, and do not significantlyinhibit their use.

6.1.3 Reliability and quality controlThis was identified as a key factor in determining theacceptability of recycled and secondary aggregates in2001. The perception of recycled and secondaryaggregates as highly variable and of low quality haschanged somewhat, particularly with public sector clients

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Table 5 Summary of issues relating to recycling in transport infrastructure, 2001

Issue Description Available guidance Recommended action required

Specifications. Some materials and methods are A number of specifications for Update existing specifications to accommodateexcluded from existing specifications. alternative materials and methods new developments more quickly, or write new

are available. Specifications for particular applications.

Test methods. Existing test methods developed for A number of tests have been assessed as Move to performance-based test methodsnatural materials are not suitable for suitable for alternative materials. and specifications.some alternative materials.

Reliability and quality control. Alternative materials perceived as Utilise or adapt existing quality control Demonstrate quality of materials producedhighly variable and of low quality. systems to produce a consistent, under a quality plan, upgrade processing

fit-for-purpose material. plant to produce higher quality material.

Environmental concerns. Potential long term leaching of Assess behaviour using leaching tests Agreement between environmentalcontaminants into controlled waters; dust and existing models where necessary; regulators and material producers on use ofand noise during construction. CDM/COSHH legislation. materials in construction.

Waste regulation including Unclear whether materials are waste or Use available guidance on waste Approach environmental regulators for advice atwastemanagement licensing covered by exemptions, potential long permitting system. early stage in design of project. DEFRA areand PPC regime. time scale required by waste permitting reviewing exemption system to ensure alternative

processes. materials can be used in construction.

Conditions of contract. Some forms of contract may create an Use appropriate forms of contract and Review standard conditions of contract toenvironment where there is no incentive adopt partnering. rectify any clauses discriminating againstfor innovation. innovative materials or methods.

Planning. Difficulties getting planning permission Guidance for planners and applicants Ensure an adequate supply of recyclingfor recycling centres in or near urban areas. has been produced by DETR. centres is available to meet local needs.

Supply and demand. Difficulty in matching supply and demand Plan in advance and stockpile material Develop long term partnering agreements tofor some alternative materials. if necessary; use existing databases to enable better prediction of material

source materials. requirements.

Economics. Alternative materials and methods may be Ensure comparing like with like; use Adjust aggregates levy and landfill tax asmore expensive than conventional ones. whole life costing to ensure best practical necessary to ensure alternative materials

environmental option selected. remain competitive.

Lack of awareness. Many individuals and organisations Disseminate existing information from Develop strategies to reach resistant sectorsunaware of the possibilities, or only aware CIRIA, EA, TRL, BRE, AAS and others. of industry and infrastructure owners.of potential problems.

24 Table 6 Summary of issues relating to recycling in transport infrastructure, 2005

Issue Description Available guidance Recommended action required

Specifications. Some materials and methods are excluded from Most specifications and standards now cover use Update specifications in line with new developments.existing specifications. of recycled and secondary aggregates (see 6.1.1).

Test methods. Existing test methods developed for natural materials Some performance based test methods are available; Move to performance-based test methods and specifications.are not suitable for some alternative materials. test methods being developed via EC project

SAMARIS (see 6.1.2).

Reliability and quality control. Alternative materials perceived as highly WRAP quality protocol for production of aggregates Demonstrate quality of materials produced under a quality plan,variable and of low quality. from inert wastes (see 6.1.3). upgrade processing plant to produce higher quality material.

Environmental concerns. Potential long term leaching of contaminants into Assess behaviour using leaching tests and existing Develop protocols for secondary aggregates.controlled waters; dust and noise during construction. models where necessary (see 6.1.4); CDM/COSHH

legislation.

Waste regulation including Unclear whether materials are waste or covered by Use guidance in waste management regulations Continued liaison between industry, WRAP, the Environmentwaste management licensing exemptions, potential long time scale required module on www.aggregain.org.uk (see 6.1.5). Agency and DEFRA to avoid conflicts in the future.and PPC Regime. by waste permitting processes.

Conditions of contract. Some forms of contract may create an environment Use appropriate forms of contract and adopt Monitor effectiveness of forms of contract and adaptwhere there is no incentive for innovation. partnering and early contractor involvement to where necessary.

stimulate innovation (see 6.1.6).

Planning. Difficulties getting planning permission for Include requirements for facilities in minerals and Ensure an adequate supply of recycling centres is available toaggregate recycling centres. waste development frameworks; use guidance in meet local needs; engage stakeholders in consultation at an early

planning module on www.aggregain.org.uk (see 6.1.7). stage.

Supply and demand. Difficulty in matching supply and demand for Provide necessary facilities for storage and treatment Long term partnering agreements to enable better prediction ofsome alternative materials. of materials; divert recyclable material from exempt material requirements; divert recyclable material from exempt

sites (see 6.1.8). sites.

Economics. Alternative materials and methods may be more Use case studies on www.aggregain.org.uk to Adjust aggregates levy and landfill tax as necessary to ensureexpensive than conventional ones. demonstrate that recycled aggregates are often alternative materials remain competitive.

cheaper than primary ones (see 6.1.9).

Lack of awareness. Many individuals and organisations unaware of the Disseminate existing information from WRAP, Develop strategies to reach SME sector; continue to addresspossibilities, or only aware of potential problems. CIRIA, EA, TRL, BRE and others (see 6.1.10). major clients and construction professionals.

25

such as local authorities, as a result of governmentinitiatives on sustainability and increased experience oftheir satisfactory use. It remains a problem with manyprivate clients and developers, particularly for the Small toMedium Enterprises (SME) sector.

BR392 ‘Quality control: the production of recycledaggregates’ was referenced in ‘Recycling in transportinfrastructure’. This proved very successful in ensuring thequality of recycled aggregates, and was used successfullyon major projects such as the widening of the M25between J12 and 15 (see the case study onwww.aggregain.org.uk). In 2004 BR 392 was supersededby the WRAP quality protocol for the production ofaggregates from inert waste (Waste and Resources ActionProgramme, 2004), which incorporated the newharmonised European Standards for aggregates andincluded clarification on the issue of when materialsceased to be waste (see 6.1.5). The WRAP quality protocolhas been very successful and provides a framework forproducers to confirm that their products are fit for purposeand have been fully recovered. It is important for clients toinsist that producers use this protocol. This will force upstandards in the recycling industry and defeat the problemof ‘cowboy’ recyclers who provide material of low qualityand bring the industry into disrepute.

The quality protocol was developed by WRAP throughdiscussions with the Environment Agency and the QuarryProducts Association. Following the successful productionof this protocol, work started on similar protocols forpulverised fuel ash (PFA), steel slag and incineratorbottom ash aggregate. These secondary aggregates areextensively used in construction and there is considerablepotential to increase their use, so protocols for thesematerials would be very valuable. However, we understandthat there is little likelihood of these protocols beingfinalised in the near future. This is an important area andwe would urge that higher priority should be given toagreeing protocols for these materials.

6.1.4 Environmental concernsThis was raised as an area of potential concern,particularly for materials with potentially leachableconstituents when used in sensitive areas such as majoraquifers. The WRAP quality protocol has helped; as it isfor the production of aggregates from inert waste, bydefinition they are unlikely to give rise to environmentalproblems. Consideration should always be given tospecific circumstances however. Recycled concreteaggregate often has a high pH, for example, and should notbe used below water near to sensitive groundwater orsurface water receptors.

Similar protocols for other secondary aggregates wouldbe very helpful in defining where they could and could notbe used, as noted in the previous section. Use of materialsin bound form, such as asphalt or concrete, is likely to bemuch less contentious than use in unbound form, becausethe potential for release of contaminants is greatly reduced.

Case study: use of incinerator bottom ash aggregate inbound formThe use of incinerator bottom ash aggregate (IBAA) inbound form in the Bar End HWRC case study illustrateswhat can be achieved when all parties work together. TheEnvironment Agency were very supportive of the use ofIBAA in this application, as a constructive use of amaterial that would otherwise be landfilled, but theyrequired a risk assessment and leaching tests to be carriedout on the IBAA itself and on the asphalt containing theIBAA. The risk assessment concluded that the proposeduse of IBAA in the base and binder of the path androadway up to the waste transfer station was unlikely tohave any adverse health or environmental effects.However, a programme of testing and monitoring was setup to provide reassurance on this point; this is reproducedin Figure 7.

The BS EN 12457: Part 3 two-stage batch leaching testwas carried out on the IBAA and the results compared toWaste Acceptance Criteria (WAC) for granular stable non-reactive hazardous waste (Statutory Instrument 2004 No.1375). This was to ensure that the IBAA had been properlyprocessed before incorporation into the asphalt. Freshincinerator bottom ash (IBA) is strongly alkaline andproduces leachate with very high concentrations of metals,sometimes in excess of the WAC for hazardous waste.Fresh IBA should not be used as aggregate, either in boundor unbound form. Weathering the material for at least sixweeks allows hydration and carbonation reactions to occur,the pH drops and the solubility of metals and othercontaminants is greatly reduced. The leaching test was aquality control test to ensure that the material had beenweathered properly before being used in asphalt.

150 mm cube samples of the asphalt were taken at thetime it was placed, cured for 28 days then subjected to atank leaching test according to the Dutch Standard NEN7345 as a check on the leachability of the final product. Thecumulative release of all species from the cube samples wasvery low and did not give any cause for concern.

The procedures adopted for the Bar End site confirmedthat when used properly IBAA can be incorporated inasphalt pavement layers other than the surface coursewithout any significant risk to the environment. Havingestablished this principle, it should be possible to use thismaterial widely without having to carry out all the leachingtests on each occasion. However, it is important to ensurethat the materials are properly weathered before use, and aregular programme of batch leaching tests should becarried out by the producer to provide reassurance on thispoint. It is also important that the material is placed andcompacted properly to ensure that there is no risk ofrelease of contaminants. This can be demonstrated bystandard engineering tests such as density and stiffness,which are carried out on the material to ensure it meets theengineering requirements for the application.

Statutory Instrument 2004 No. 1375 contains WAC forinert, granular stable non-reactive hazardous waste andhazardous waste, based on chemical analyses of a fewparameters on the solid waste and the cumulative leachingresults using the BS EN 12457: Part 3 two-stage batch

26

Tests on IBA Site Monitoring

Carry out BS EN12457-3 test on weathered IBA

Results below WAC for

SNRHZW?

Continue weathering

materialNo

Yes

Use IBA in foamix: construct in accordance with Method

Statement

Confirm physical properties by

engineering tests during construction

Carry out tank tests on foamix in accordance with NEN 7345

Results below WAC for SNRHZW for

monolithic waste?

Yes

Extract cores after one year and test according to NEN 7345

Results below WAC for SNRHZW for

monolithic waste ?

Yes

No further action unless monitoring of balancing pond or River Itchen

indicates that some release of contaminants may have taken place

Take baseline samples from balancing pond

and River Itchen

No

Extract cores and carry out tank tests to

NEN 7345:Increase frequency of

monitoring of balancing pond and River ItchenCarry out quantitative

risk analysis

Routine monitoring of balancing pond and River

Itchen

Results within relevant water

quality standards (to be defined)No

Monitoring of balancing pond and River Itchen

after one year.

Yes

Results below water quality

standards (to be defined)?

Yes

Reduce frequency of monitoring. No further action unless results exceed water

quality standards (to be defined).

NoNo

Increase frequency of monitoring/core testing.Carry out quantitative

risk analysis

Figure 7 Flow chart for environmental testing at Bar End

WAC = Waste Acceptance Criteria

SNRHZW = Stable non-reactive hazardous waste

27

leaching test. These WAC values may provide a basis forrisk assessments for the use of recycled and secondaryaggregates, as the Environment Agency are familiar withthem. As in all cases where there are potentialenvironmental concerns, liaison with the EnvironmentAgency should be undertaken from an early stage of theproject to establish what the issues are and how theyshould be addressed.

6.1.5 Waste management regulationsFew topics have generated so much controversy in recentyears as the application of the Waste ManagementLicensing regime to the use of recycled and secondaryaggregates. The interaction between regulatory regimes onwaste management, driven by case law in the EuropeanCourt and government driven initiatives on sustainabilityresulted in a situation where, under a strict interpretation ofthe law, recycled aggregates were regarded as waste untilthey had been placed in their final resting place, e.g. ascapping materials or sub-base in a road construction. Thismeant that all sites using recycled aggregates had, intheory, to register an exemption from the WasteManagement Licensing Regulations. The threat of thisproved a significant disincentive to the use of recycledaggregates and, if it had been widely implemented, couldhave reversed the increase in use of recycled aggregatesthat had occurred in previous years.

At the time of ‘Recycling in transport infrastructure’, theconsensus was that recycled aggregates ceased to be wasteonce they had been processed so that they could be used inconstruction in the same way as primary aggregate. Thismeant that the ‘point of recovery’ was at the recycling plant,and recycled aggregates were not regarded as waste whenthey left the plant to go to a construction site. WasteManagement Regulation in the UK is governed byEuropean Directives, and various cases in the EuropeanCourt affected the position of the ‘point of recovery’, so thatit was now on the construction site for recycled aggregates.

The situation was resolved by negotiations betweenWRAP, the Quarry Products Association, the HighwaysAgency and the Environment Agency which resulted in theproduction of the WRAP quality protocol ‘for theproduction of aggregates from inert waste’. This includeda list of wastes considered to be inert waste for the purposeof the protocol, provided there was no suspicion ofcontamination, which included most of the materials fromwhich recycled aggregates are generally manufactured,including concrete, bricks, tiles, ceramics, soil and stones,road base and planings, track ballast and glass. Thedocument was essentially an update of the earlier BR392quality protocol. The purpose of the protocol was stated as‘to provide a uniform control process for producers bywhich they can reasonably state and demonstrate that theirproduct has been fully recovered and is no longer awaste.’ The Environment Agency has circulated theprotocol to their staff and advised them to also takeaccount of it in their decision-making.

The effect of the WRAP quality protocol is effectivelythat recycled aggregates produced in accordance with itwill not be regarded as wastes, and sites which receive the

recycled aggregates will not have to register exemptionsfrom the Waste Management Licensing Regulations. The‘point of recovery’ has been effectively moved back to therecycling plant, for recycled aggregates produced inaccordance with the protocol. It is therefore very importantthat the protocol is widely used, and that it is not abused,e.g. by using it to treat contaminated or organic materials.This could bring the protocol into disrepute, and lead tothe Environment Agency changing their position on it. It isimportant for clients and designers to insist on the use ofthe protocol, not only to ensure the quality of the materialsbut also to avoid any disputes over whether the materialsare waste or not.

The subject of waste management regulation and itsinteraction with the use of recycled and secondaryaggregates remains a complex one, and furtherdevelopments may occur in the future. A useful guide to thecurrent situation, including changes introduced in July 2005,is available in the Waste Management Regulation module ofthe AggRegain web site (www.aggregain.org.uk).

6.1.6 Conditions of contractRecycling in transport infrastructure concluded that, whilesome forms of contract could act as a discouragement tothe use of recycled and secondary aggregates, the mostimportant factor was not the particular form of contract butthe spirit in which it was operated by all parties. Partneringwas encouraged as a way to develop good relationsbetween parties and encourage innovation.

The success of the partnering approach adopted byHampshire County Council for highways maintenancedemonstrates the advantages of this approach. All partiesfeel involved and work towards common goals, there is aclear policy lead from the client towards more sustainableconstruction, early contractor involvement has resulted in anumber of innovative approaches and development of newmethods and materials, logistical arrangements have beenmade to enable the use of recycled materials, and techniquesand specifications have been updated to enable recycling.

The partnering approach is being adopted more widelyin construction, including several county councils whohave set up partnering arrangements for highwaymaintenance, including Essex, Surrey and Staffordshire.Details of ways in which conditions of contract can beused to increase the amount of recycling in local authoritycontracts for highway maintenance are given in the WRAPguidance document ‘The Big Picture’ (Waste andResources Action Programme, 2004b), which is availableon the AggRegain web site (http://www.aggregain.org.uk/procurement/quick_wins/index.html).

While partnering is a good way to encourage recycling,it is not essential. With the right approach, recycling can becarried out under most forms of contract, including thetraditional Institution of Civil Engineers (ICE) Conditionsof Contract for Works of Civil Engineering Construction.What is essential, however, is a clear lead from the clientand commitment from all parties. This is demonstrated bya series of supply chain case studies developed by TRL forWRAP, available at (http://www.aggregain.org.uk/applications/aggregain/casestudysearch/index.rm).

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6.1.7 Planning‘Recycling in transport infrastructure’ identified that therecould be difficulties in obtaining planning permission forsites to produce recycled aggregates. This remains thecase, although planning guidance for some regionsrecognises the need to provide for an adequate number offacilities and has widened the potential areas where suchsites would be permitted (South East England RegionalAssembly, 2004). Many local authorities are now lookingto recycled and secondary aggregates as a way of reducingthe amount of primary aggregate extraction they arerequired to make provision for, so the need for facilities toprocess the recycled and secondary aggregates to thestandards needed for the construction industry – e.g. theWRAP quality protocol – is accepted. The approachadopted in Hampshire, to integrate the provision offacilities within an overall framework for minerals andwaste development (Hampshire County Council,Portsmouth City Council and Southampton City Council,2005), is described in Chapter 5. Information on applyingfor permission for an aggregate processing facility inEngland is available on the AggRegain web site at http://www.aggregain.org.uk/planning/index.html.

In practice, applications for new sites or extensions toexisting sites may still be turned down, even if they aresupported by the council officers, because of publicconcerns about traffic, noise, dust, environmental damageand visual intrusion. Conflicts of this sort are likely tocontinue, as nobody wants a recycling centre near themhowever much they agree with the principles of recycling.However, if applications for sites are submitted in line withplanning guidance they are likely ultimately to besuccessful, even if they have to go to the Secretary of Stateon appeal. The provision for the Secretary of State toaward costs against councils who turn down applicationsthat are subsequently upheld on appeal ought to act as adeterrent to councils turning down applications that are inline with planning guidance. The consultation approachadopted by Hampshire, Portsmouth and Southamptonshould also help to reduce the number of objections to sitesby involving all stakeholders in the selection process.

If the targets for increased use of recycled andsecondary aggregates under the ‘stretching best practice’scenario are to be met, there will need to be an increasingsupply of quality materials. This in turn will require anadequate supply of reprocessing facilities to producematerials to the required standards. There is some debateas to whether these are best met by a few large,strategically located facilities or a network of smallerfacilities closer to the sources of the materials(Hampshire County Council, Portsmouth City Counciland Southampton City Council, 2005). This raises anumber of issues. It may be easier to obtain planningpermission for a few large sites, but is this in effectcreating a monopoly for a small number of producers?There are clearly economies of scale with large facilities,but will this result in an overall increase in transportdistances compared to a larger number of smaller siteslocated closer to the arisings? The proximity principlesuggests that wastes should be dealt with as close as

possible to their point of origin. These issues will have tobe worked out and a satisfactory balance achievedbetween the various factors. Planning permission willcontinue to be an issue of critical importance for the useof recycled and secondary aggregates.

As well as being a potential barrier to recycling, theplanning system can also act as an enabling agent,particularly for redevelopment of existing sites throughtools such as the Demolition Protocol (EnviroCentre,2004) (see Chapter 3.3.2). The Demolition Protocol isavailable at http://icextra.ice.org.uk/tlml/demolition. It canalso be accessed via the demolition module of theAggRegain web site.

6.1.8 Supply and demandMatching supply and demand remains one of the mostdifficult aspects of recycling, particularly ensuring acontinuing supply of high quality materials. The issuesrelating to planning permission for recycling facilities havebeen discussed in the previous section. A supply of lowquality materials does no good for the image of recycling,and can only depress the market for materials that areproperly produced in accordance with protocols such asthat developed by WRAP. There is an onus on clients,particularly in the public sector, to ensure that protocols,standards and specifications are included in contracts andtheir use is enforced. Over time this will force industrystandards up and enlarge the market for recycled materials,as clients, contractors and suppliers gain more experiencewith them.

A number of major producers are leading the way withprovision of high-tech facilities to produce high qualityrecycled aggregates that can be used in applications suchas concrete and asphalt. The plant set up in Brentford,London by Day Aggregates was highlighted in ‘Recyclingin transport infrastructure’. More recently, FM Conwayhas set up a facility at Dartford for processing highwayarisings that includes an aggregate washing plant, gullywaste treatment plant and cold recycled bitumen boundmaterial plant as well as the conventional crushers andscreeners. The outputs include concrete up to C30 strengthwith 100% recycled aggregate and a variety of coldrecycled bitumen bound products. Coleman and Co set upa similar ‘urban quarry’ to process construction anddemolition waste into high quality aggregates inBirmingham in 2005 (Anon, 2005).

Partnering is one way of ensuring that supply anddemand issues are addressed. The success of the partneringapproach adopted by Hampshire County Council,Raynesway Construction Southern and Foster Yeoman forhighway maintenance in Hampshire would not have beenpossible without the provision of adequate facilities forstoring and processing materials. A network of storagesites for surface dressing materials was set up across thecounty, enabling the reuse of some 4,000 tonnes of thismaterial (Chapter 4.1.3). Two segregation plants were setup, at Alton and Petersfield. These were waste transferstations which were set up to receive arisings fromhighway works. The materials were sorted into categoriessuch as concrete, asphalt, granular material and clay, so

29

that they could be reused for the highest valueapplications. The materials were stockpiled until sufficientvolumes were available for reuse. They were then sent tonearby recycling centres for processing to meet theappropriate specification requirements and reused infurther works.

Two asphalt plants were also set up at Botley in the southof the county near the large urban areas of Portsmouth andSouthampton, and at Micheldever in the centre of thecounty. Foster Yeoman set up a mobile Foamix® plant atthe Micheldever depot to process arisings from across thecounty. For example, asphalt planings from the A325maintenance scheme at Alice Holt were sent to theMicheldever plant for processing into Foamix® for useelsewhere in the county, including the North PopleyDevelopment (Chapter 4.1.6). As well as recycled asphalt,the plant can handle a number of other recycled andsecondary aggregates. The IBAA used at Bar End (Chapter4.1.4) was made into Foamix® at the Micheldever plant.

The provision of adequate sites, not only forreprocessing materials but also for storing them, isimportant for recycling in activities such as highwaymaintenance, where there is a continuous supply ofarisings from different sites that require to be processedand are then used on other sites. This can be a particularproblem in urban areas, where it can be difficult to providesites with sufficient storage space because of high pricesand pressure on land use.

At the other end of the scale, there was considerableconcern in 2001 about potentially recyclable materialsbeing sent to exempt sites and deposited as low value fill.Changes to the Waste Management Regulations regardingexemptions to the waste management licensing processcame into force in July 2005 (see waste managementregulations module on AggRegain). These impose morestringent requirements for operators of exempt sites,including provision of information on the material beingdeposited, and the introduction of charges for exemptions.These new requirements should act as a disincentive to thedumping of material on exempt sites. Also, with increasingdemand for recycled aggregates, it is increasingly moreeconomic to process the material and sell it as recycledaggregate than to dump it. If the ‘stretching best practice’targets for Hampshire are to be met, it will be necessary todivert some CD&EW that is currently sent to exempt sitesto recycling plants.

On the demand side, there has been a lot of progresssince ‘Recycling in transport infrastructure’ in developingmarkets for recycled and secondary aggregates. Much ofthis has come about through public sector clients, such aslocal authorities, who have identified sustainability as animportant guiding principle in their activities and put inplace measures to achieve it. This also applies to otherinfrastructure owners such as the Highway Agency andBritish Airports Authority. The use of the DemolitionProtocol and the inclusion of targets for recycled contentin the forthcoming Code for Sustainable Building will alsodrive the demand side. There remains a need to stimulatedemand among other private sector clients. This will beessential if the targets are to be met. This topic is addressedmore fully in Chapter 6.1.10, Lack of awareness.

With pressure to increase the use of recycled andsecondary aggregates, the issue of matching supply anddemand will continue to be important.

6.1.9 EconomicsThe bottom line is always crucial, and the use of recycledand secondary aggregates will be limited if they are, or areperceived to be, more expensive than primary aggregates,however sustainable their use might be. The AggregatesLevy has helped to make recycled aggregates morecompetitive. However, recycled and secondary aggregatesare often cheaper than primary aggregates, particularly inapplications such as highway maintenance when the basicoperations are generating a supply of materials that can berecycled and reused. Savings of over £28,000 were madeby reusing surface dressing chippings in Hampshire(Chapter 4.1.3).

A number of examples of cost savings by usingrecycling are given in ‘The Big Picture’ (Waste andResources Action Programme, 2005b) and in supply chaincase studies on the AggRegain web site (http://www.aggregain.org.uk/applications/aggregain/casestudysearch/index.rm), including:

! Use of 750,000 tonnes of recycled aggregates on theM25 J12 to 15 widening contract was up to £4 per tonnecheaper than equivalent primary aggregates.

! Use of road planings stabilised with PFA and lime inStaffordshire resulted in savings of 40% on the base andsub-base layers.

! Cement and lime stabilisation of in situ soils led to costsavings of 20% compared to excavation andreplacement with primary aggregate in haunching worksin Staffordshire.

! Use of locally available recycled and secondaryaggregates in a household waste recycling centre inDevon was no more expensive than use of primaryaggregates.

! Use of in situ cold recycled bitumen bound material forrepairs to a major road in Portsmouth, using arisingsgenerated from the site, saved 25% to 30% on cost andtime compared to conventional repairs.

Increasingly, therefore, recycling is seen as a costeffective option as well as being environmentally friendly.

Funding for capital infrastructure for the production ofrecycled and secondary aggregates has been available fromWRAP under several programmes since 2002. This hashelped to put in place the infrastructure necessary todeliver the quantity and quality of recycled aggregates thatwill be needed in the future. Increasingly WRAP arefunding high quality facilities such as the ‘urban quarry’described in 6.1.8 rather than basic crushing and screeningplant, to drive the use of recycled and secondaryaggregates to higher value products.

6.1.10 Lack of awarenessIn ‘Recycling in transport infrastructure’, this wasidentified as perhaps the biggest single factor inhibitinggreater use of recycled and secondary aggregates. While

30

there were issues that needed to be resolved with some ofthe other topics, they were not insoluble provided therewas a will to succeed. Overcoming the perceptionalbarriers and misconceptions about recycled materials wasthe key to enabling their greater use.

Since 2001 there have been a number of initiatives indifferent ways in this area. Arising directly out of theexperience of ‘Recycling in transport infrastructure’, TRLput together two roadshows under the heading ‘SustainableConstruction in Practice’ (SCiP) with the aim of takinginformation on recycling to practising constructionprofessionals across the UK. The roadshows werecollaborative ventures involving presenters from industry(contractors, suppliers and designers), regulators(Environment Agency) and researcher organisations (TRL/Viridis, CIRIA) and combined presentations on relevanttopics and case studies with workshop sessions where theprinciples were worked out in the context of practicalexamples. SCiP roadshows were run in the winters of2002/03 and 2004/05, visiting England, Scotland, Walesand Northern Ireland. A total of 19 events were heldbetween the two roadshows. They proved very popular,attracting on average 50 delegates to each event, with verypositive feedback from the delegates, who came from localauthorities, contractors, designers and aggregate suppliers.Both SCiP roadshows were funded under the Partners inInnovation programme by the Department of Trade andIndustry, with additional funding from the CountySurveyors Society, Institution of Civil Engineers, RoyalInstitution of Chartered Surveyors, Tarmac, AggregateIndustries, Ballast Phoenix and the Waste and ResourcesAction Programme (WRAP).

The Waste and Resources Action Programme (WRAP)

WRAP is a major government programme established topromote sustainable waste management by tackling thebarriers to waste minimisation and increased recycling.Aggregates were added to its portfolio in 2002, and theWRAP Aggregates Programme aims to promotesustainable use of aggregates through encouraging greateruse of recycled and secondary aggregates by addressingthe barriers to increased use. They have done this partlythrough providing economic support for the provision ofrecycling infrastructure (Chapter 6.1.9), partly throughacting as an ‘honest broker’ between industry andregulators to resolve the waste management licensing issueby production of the WRAP quality protocol (Chapter6.1.5), but mainly through a range of promotional anddissemination activities.

One of their first actions was to set up a web site,AggRegain (www.aggregain.org.uk) to act as a ‘one-stopshop’ for information on recycled and secondaryaggregates. The site went live in February 2003 and beendeveloped considerably since, most notably in July 2005.It now contains the following features:

! The Specifier tool, which allows users to establish howrecycled and secondary aggregates can be used in arange of construction applications under existingspecifications.

! A supplier directory.

! A number of case studies demonstrating the use ofrecycled and secondary aggregates in a range ofconstruction applications and demonstrating costbenefits and comparative performance compared toprimary aggregates.

! Access to the WRAP quality protocol and a number ofother WRAP publications on recycled and secondaryaggregates, including ‘The Big Picture’.

! Modules on planning, recycling infrastructure, quality,waste management regulations, demolition, procurementand sustainability related to recycled and secondaryaggregates.

! Links to the WRAP web site and a number of otherrelated sites.

WRAP have also been very much involved in activedissemination, through launch events for AggRegain andpublications like ‘The Big Picture’ and through morestructured programmes. In 2005 they ran a series of one dayworkshops for local authority highway engineers in Englandunder the title ‘Recycled Roads’. This used the same formatas SCiP and involved presenters from WRAP, TRL, BRE,Atkins and Capita Symonds. Ten events were held, with anaverage of 50 delegates attending and giving very positivefeedback. The events also helped to establish a baseline ofthe level of recycling carried out by local authorities inhighway maintenance in England. WRAP also held a seriesof events on the broader topic of recycling in construction,including building products, aimed more at clients,designers and influencers under the title ‘ReConstruct’. Aseries of workshops to disseminate the use of the DemolitionProtocol is planned for early 2006, and a further series of‘Recycled Roads’ will also be held.

There has therefore been considerable progress inaddressing the problem of lack of information, certainlyamong construction professionals and major clients.Combined with continuing government initiatives onsustainability and work by other organisations such asCIRIA and BRE, and numerous articles in technicaljournals such as Surveyor, Highways, NCE, ConstructionNews and the Contract Journal on recycling, mostconstruction professionals are aware of the concept ofsustainability, what it might mean in practice, and thatusing recycled and secondary aggregates is not onlypossible but positively desirable.

Where progress has been less marked is in the SMEsector. This is highly diverse and difficult to reach, buteventually the message will get through if only indirectlythrough escalating charges for sending material to landfill orincreasing requirements from local authorities, either asclients or regulators (Planning and Building Control). Thereneeds to be more of a focus on this area to encourage smallclients and builders to adopt recycled materials, and to usematerials that have been processed properly in accordancewith the WRAP quality protocol rather than unsortedCD&EW passed off as recycled aggregates.

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6.2 Summary: progress and the way forward

There has been considerable progress since 2001 on anumber of the issues highlighted in ‘Recycling in transportinfrastructure’, particularly:

! Updating a number of specifications to permit the use ofrecycled and secondary aggregates.

! Development of the WRAP quality protocol.

! Resolution of potential problems with the WasteManagement Licensing regime.

! Widespread development of partnering and earlycontractor involvement.

! Increasing commitment of major clients to principles ofsustainability and the working out of this in policies andactivities.

! Recognition of the need to provide adequate facilitiesfor producing recycled and secondary aggregates andthe development of a comprehensive planningframework for minerals and waste.

! Increasing use of recycled and secondary aggregates inhigher value applications and the establishment of plantsto produce materials of the required quality.

! Extensive programmes of dissemination have largelyaddressed the problem of lack of awareness amongmajor clients and construction professionals.

! The development of the WRAP Aggregates Programmehas had a major effect on lack of awareness, capitalsupport for recycling infrastructure and resolvingconflicts with the Waste Management Licensing regime.

Some areas of actual or potential difficulty remain ifrecycled and secondary aggregates are to fulfil the role, interms of quantity and quality that is increasingly beingexpected of them. These are summarised in Table 6 andinclude:

! Need to obtain planning permission for an adequatenumber of recycling facilities.

! Need to develop quality protocols for secondaryaggregates.

! Need to stimulate more use of recycled and secondaryaggregates in high value applications.

! Need to divert more CD&EW from exempt sites torecycling centres.

! Need to address lack of awareness in the SME sector ofthe construction industry.

! Need to incorporate use of recycled and secondaryaggregates in overall strategies for sustainability.

! Need to use tools such as the Demolition Protocol andCode for Sustainable Building to increase the amountand level of recycling.

! Need to continue to foster joint commitment to goalsand capture innovation by early contractor involvementthrough partnering and other means.

! Need for continued liaison with the EnvironmentAgency to avoid future conflicts with the WasteManagement Licensing regime.

! Need for continued dissemination of good practice andresearch to address areas of uncertainty or difficulty.

While these issues need to be addressed, the tide is nowrunning firmly in favour of recycled and secondaryaggregates. The fundamental principles are widely agreed,and it is the details that need attention to ensure that thepotential is achieved. The work carried out by HampshireCounty Council and their approach to the overall issues ofminerals and waste, described in the earlier chapters of thisreport, illustrate what can be achieved if there is a clearcommitment from the client. There is a need for thisapproach to be more widely adopted to maximise thepotential use of recycled and secondary aggregates inhighway maintenance and other construction activities.

7 Conclusions

The actions of Hampshire County Council and Portsmouthand Southampton City Councils through the MaterialResources Strategy (MRS) and the partnering arrangementwith Raynesway Construction Southern and FosterYeoman for highway maintenance has demonstrated howthe use of recycled and secondary aggregates can beincreased by a proactive approach as part of an overallstrategy on sustainability. The demonstration projectsillustrate some of the ways in which this can be achievedin practice, particularly in the context of local authorityhighway, waste and development activities. It alsoillustrates how planning for future needs can be undertakenthrough the statutory minerals and waste developmentframework, based on analysis of the materials available inthe area and stretching but achievable targets for futureuse. Consultation with key stakeholders in the communityhas been given high priority through the MRS, and hasenabled a consensus to be achieved on the overall strategyand the particular actions needed to turn it into reality. Thisapproach may be a model for other local authorities toachieve increases in use of recycled and secondaryaggregates as part of an overall strategy on sustainability.

A number of factors were critical for the success ofrecycled and secondary aggregate use in Hampshire:

! There was a clear lead from the client and coordinationwith other recycling initiatives.

! There was early involvement of contractors and otherrelevant stakeholders.

! Logistical arrangements were put in place, e.g. storagedepots and recycling plant.

! Locally available materials were used.

! Modern specifications, design guides and qualityprotocols were used and new ones were developedwhere necessary.

The use of recycled and secondary aggregates not onlyresulted in environmental gains, such as reduced use ofprimary aggregates, reduced disposal of material to landfilland reduced emissions of CO

2, but also reduced costs in

most cases.

32

A number of issues were identified as key to increaseduse of recycled and secondary aggregates in a TRLpublication ‘Recycling in transport infrastructure’ in 2001.These were reviewed and it was found that there had beenconsiderable progress on a number of the issues,particularly in the greater use of partnering and earlycontractor involvement, updating of specifications,standards and quality protocols, resolution of conflictswith the Waste Management Licensing regime andaddressing the lack of awareness among constructionprofessionals and major clients. The WRAP AggregatesProgramme has made a very significant contribution tothis, particularly in the provision of guidance through theweb site www.aggregain.org.uk. .

A number of areas remain where obstacles to recyclingcould still occur, such as obtaining planning permission forrecycling facilities, developing protocols for secondaryaggregates and addressing the lack of awareness issue forthe SME sector. These should be addressed, but it is feltthat the principles of using recycled and secondaryaggregates are firmly established and that most of theissues are concerned with the details of making it work inpractice. Provided these issues are addressed, targets forincreased use of recycled and secondary aggregates anduse in higher value applications can be met.

It is important that use of recycled and secondaryaggregates is seen as part of an overall strategy onsustainability and co-ordinated with other activities, notseen as an end in itself. The MRS approach adopted byHampshire County Council, Portsmouth and SouthamptonCity Councils provides a good example of how this can beachieved. Local authorities are major construction clientsand also have a large influence on activities in their areathrough the planning system and by the example they set,so it is important that they take the lead in implementingan agenda for sustainability that includes maximising theuse of recycled and secondary aggregates. The role of localauthorities in moving from strategy and policy toimplementation through integration with their otherfunctions is critical; joining up functions and usingprocurement to encourage a move to a ‘closed loop’system. The public sector as a whole has a key role to playin delivering sustainability, given the size of it’sconstruction budget.

8 Acknowledgements

The work described in this report was carried out in theResource Management Group of TRL Limited. Theauthors are grateful to Dr John Lewis who carried out thequality review and auditing of this report. The project wasfunded by the Department of Trade and Industry throughthe Partners in Innovation Programme, Contract No.STBF/004/00090C, cc2504. The contract was awarded toViridis, the waste and resource management arm of theTransport Research Foundation and sister company toTRL, and the work was subcontracted to TRL.

The authors are also grateful to the members of theproject Steering Group and their colleagues who provided

information, advice and contacts in the preparation of thisreport. The members of the project Steering Group were:

Julie Crouch Hampshire County Council,Waste Management Section.

Emily Moon Hampshire County Council,Waste Management Section.

Jeremy Smith Hampshire County Council,Minerals and Waste Planning.

Terry Lomas Hampshire County Council,Technical Advisers Group.

Terry Williams Hampshire County Council,Engineering Consultancy.

Andy Harding Hampshire County Council,Highways Maintenance.

Ian Avery Hampshire Natural ResourcesInitiative.

Stewart Giddings Raynesway Construction.Southern Ltd.

Lloyd Allen Raynesway Construction.Southern Ltd.

Peter Cross Dean & Dyball Construction Ltd./Institution of Civil Engineers.

Martin Dudley Foster Yeoman Ltd.

Peter Kelly Environment Agency.

Russell Wolstenholme W S Atkins (Project Officer forDTI).

9 References

Anon (2005). Well-maintained Highways: Code of Practicefor Highway Maintenance. London: The Stationery Office.

Anon (2005). Coleman opens ‘urban quarry’. MiningQuarrying & Recycling, 34 (3) May/June 2005.

Barritt J (2003). Overcoming Barriers to Recycling -Addressing Government Sustainability and Recycling Targetsfor Construction and Related Industries. Paper presented atthe 2nd International Conference Liverpool John MooreUniversity. Wednesday February 26th 2003.

British Standards Institution (2002). Characterisation ofwaste. Leaching. Compliance test for granular wastematerials and sludges. Two stage batch test at a liquid tosolid ratio of 2 l/kg and 8 l/kg for materials with a highsolid content and with a particle size below 4 mm (withoutor with size reduction). BS EN 12457: Part 3. London:British Standards Institution.

Department of the Environment, Transport and theRegions (1999). A better quality of life: a strategy forsustainable development in the UK. London: Departmentfor Transport.

33

Department of the Environment, Transport and theRegions (2000). Building a better quality of life: a strategyfor more sustainable development. London: Departmentfor Transport.

EnviroCentre Ltd (2004). Demolition ProtocolImplementation Document. Retrieved: 2005, from http://icextra.ice.org.uk/tlml/demolition.

Hampshire County Council (2005). More from Less: howto make better use of Hampshire’s material resources.Winchester: Hampshire County Council. Retrieved: 2005,from www.mrs-hampshire.org.uk.

Hampshire County Council, Portsmouth City Counciland Southampton City Council (2005). HampshireMinerals and Waste Development Framework - Strategy -Issues and Preferred Option. Winchester: HampshireCounty Council. Retrieved: 2005, fromwww.hants.gov.uk/mineralsandwaste.

Hylands K N and Shulman V (2003). Civil engineeringapplications of tyres. Viridis Report VR5. Wokingham:TRL Limited.

Merrill D, Nunn M and Carswell I (2004). A guide to theuse and specification of cold recycled materials for themaintenance of road pavements. TRL Report TRL611.Wokingham: TRL Limited.

Nunn M (2004). Development of a more versatileapproach to flexible and flexible composite pavementdesign. TRL Report TRL615. Wokingham: TRL Limited.

Office of the Deputy Prime Minister (2002a). Survey ofarisings and use of construction and demolition waste inEngland and Wales 2001. London: Office of the DeputyPrime Minister.

Office of the Deputy Prime Minister (2002b). Aggregatesprovision in England 2001-2016 - consultation paper.London: Office of the Deputy Prime Minister.

Office of National Statistics (2003). Region in figures:South East. London: The Stationery Office.

Reid J M and Chandler J W E (2001). Recycling intransport infrastructure. (MISC3). Wokingham: TRLLimited.

South East England Regional Assembly (SEERA) (2003).Aggregates Monitoring Report 2002. Guildford: SouthEast England Regional Assembly.

Sherwood P T (1995). Alternative materials in roadconstruction. London: Thomas Telford.

Sowerby C R, Lovell J and Reid J M (2005). Optimisingthe use of recycled and secondary aggregates in Hampshire.Published Project Report PPR057. Wokingham: TRLLimited.

Sowerby C R and Reid J M (2005). Hampshire CountyCouncil: material resources strategy - construction wasteand soil. Published Project Report PPR058. Wokingham:TRL Limited.

South East England Regional Assembly (SEERA)(2004). Proposed Alterations to Regional PlanningGuidance, South East - Regional Minerals Strategy.Guildford: South East England Regional Assembly.

Statutory Instrument 2004 No. 1375. The Landfill(England and Wales) (Amendment) Regulations 2004.Retrieved: 2005, from www.opsi.gov.uk/si/si2004/20041375.htm.

Waste and Resources Action Programme (WRAP)(2004). The quality protocol for the production of recycledaggregates from inert waste. Banbury: Waste andResources Action Programme. Retrieved: 2005, fromwww.aggregain.org.uk.

Waste and Resource Action Programme (WRAP)(2004b). The Big Picture: Specifying recycled in localauthority contracts for highways maintenance: Goodpractice. Banbury: Waste and Resource ActionProgramme. Retrieved: 2005, from www.aggregain.org.uk.

World Commission on Environment and Development(1987). Our common future. The Brundtland Report.Oxford: Oxford University Press.

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Abstract

Local authorities are major construction clients, particularly in areas such as highways, and hence are able to exert aconsiderable influence on the use of construction materials in their area. They are also responsible for a number ofrelated activities, such as waste management and planning, that can have a significant effect on the extent to whichrecycling of all kinds takes place. This report describes the experience of Hampshire County Council, and showshow a local authority that is committed to sustainability and prepared to take action to implement its principles canachieve considerable success in maximising the use of recycled and secondary aggregates. The current and potentialuse of recycled and secondary aggregates in Hampshire and the adjacent urban areas of Southampton andPortsmouth is described and targets are developed for 2010 and 2020. These include targets for materials used inhigh value applications such as asphalt and concrete as well as for total use of recycled and secondary aggregates.The actions that are necessary to achieve the targets are discussed, and six case studies are presented to illustratehow recycled and secondary aggregates can be used efficiently and effectively in a range of applications. Theexperience of Hampshire can be applied to other local authorities and construction clients in general. A range ofissues that were highlighted in a 2001 TRL report, ‘Recycling in transport infrastructure’, are reviewed in the lightof the experience of Hampshire and brought up to date. There has been considerable progress on a number of issues,but some potential barriers remain.

Related publications

TRL615 Development of a more versatile approach to flexible and flexible composite pavement design by MNunn. 2004 (price £50, code HX)

TRL611 A guide to the use and specification of cold recycled materials for the maintenance of road pavementsby D Merrill, M Nunn and I Carswell. 2004 (price £50, code HX)

PPR058 Hampshire County Council: material resources strategy - construction waste and soil by C R Sowerbyand J M Reid. 2005 (price £30, code 2X)

PPR057 Optimising the use of recycled and secondary aggregates in Hampshire by C R Sowerby, J Lovell and JM Reid. 2005 (price £35, code 3X)

Recycling in transport infrastructure by J M Reid and J W E Chandler. 2001 (price £35) (Ref: MISC3)

CT89.3 Aggregates in road construction update (2002-2004) Current Topics in Transport: selected abstractsfrom TRL Library’s database (price £30)

CT36.3 Recycling of road materials update (2001-2003) Current Topics in Transport: selected abstracts fromTRL Library’s database (price £30)

Prices current at February 2006

For further details of these and all other TRL publications, telephone Publication Sales on 01344 770783, email:publications@trl.co.uk, or visit TRL on the Internet at www.trl.co.uk.

Appendix A – 1

Appendix A: Summary versions of demonstration projects

Appendix A – 2

Hampshire County Council Partners in Innovation (PII)

Demonstration Project 1

Embankment Stabilisation on A325

BackgroundThis series of leaflets describes a number ofprojects demonstrating the technical,environmental and cost benefits that arise fromthe use of recycled and secondary aggregates inhighway works in Hampshire. Working inpartnership together, Hampshire County Council,Raynesway Construction Southern and FosterYeoman adopted sustainable policies for highwaymaintenance works. A Partners in Innovationproject, carried out by TRL and funded by theDepartment of Trade and Industry, enabled thesepractices to be captured in a number ofdemonstration projects. The material diverted from landfill as a result of the partnership is assistingHampshire County Council with their Public Service Agreement (PSA) target to divert an additional40,000 tonnes of material from landfill per annum by 2005.

Activity: Repair of weak clay embankment on A325.

Location: A325 near Alice Holt, N E Hampshire.

Application: Selected granular fill.

Material: Recycled aggregate.

Amount used: 29,000 tonnes.

Date: September 2004 to January 2005.

Client: Hampshire County Council.

Contractor: Raynesway Construction Southern Ltd (main contractor).

Wessex Construction Ltd (recycled aggregates)

Day Aggregates (recycled aggregates).

TJ Aggregates (recycled aggregates).

Designer: Hampshire County Council.

Specification: Specification for Highway Works.

.

SummaryEmbankment stabilisation was required on the A325 between the junction of the B3006 at Sleafordand north to the Hampshire county boundary at Holt Pond. The work covered a distance of about1.8km. The embankment was previously made up of poor quality clay. The embankment was dugout in benches and the excavated material was replaced with Class 6F5 selected granular fill (seediagram). Recycled aggregate obtained from processing inert construction and demolition wastewas used as the Class 6F5 material. The embankment ranged from 0.8 m to 5.0 m in height andthe works required a total of 29,000 tonnes of imported fill. The new embankment was built at auniform slope of 1:3. The imported fill was supplied by local suppliers Wessex Construction Ltd,Day Aggregates Ltd and TJ Transport from Selborne.

Technical benefits! The Specification called for Class 6F5 selected granular fill, which is normally

used as a coarse grained capping layer imported to site. This was to ensure a wellgraded granular material with a high angle of internal friction was used.

! Recycled aggregates performed as well as primary aggregates.

! Reduced haulage costs compared to equivalent primary aggregates.

Environmental benefits! Reduction in use of primary aggregates and reduced haulage distances.

! Reduction in overall waste being disposed of to landfill within the county.

! Savings in fuel and emissions of CO2 by using a local supply of recycled aggregates.

Benefits to local authoritiesThe use of recycled aggregates in this project had double benefits for Hampshire County Council.It contributed to targets under the Public Service Agreement for diversion of materials from landfilland also led to cost savings compared to conventional methods. Recycling had direct tangiblebenefits for the local authority as well as broader environmental and technical benefits.

New 1:3 slope being constructed

Existing soft clay fill

removed

Steps dug out from existing embankment

ROAD

Existing slope

Backfill of 6F5 material

Embankment height varies from 0.8m to 5m high

Hampshire County Council Partners in Innovation (PII)

Demonstration Project 2

Recycled Asphalt in Footway works

BackgroundThis series of leaflets describes anumber of projects demonstratingthe technical, environmental andcost benefits that arise from the useof recycled and secondaryaggregates in highway works inHampshire. Working in partnershiptogether, Hampshire CountyCouncil, Raynesway ConstructionSouthern and Foster Yeomanadopted sustainable policies forhighway maintenance works. APartners in Innovation project, carried out by TRL and funded by the Department of Trade and Industry,enabled these practices to be captured in a number of demonstration projects. The material divertedfrom landfill as a result of the partnership is assisting Hampshire County Council with their PublicService Agreement (PSA) target to divert an additional 40,000 tonnes of material from landfill perannum by 2005.

Activity: Footway renewal works.

Location: B3047 at Martyr Worthy.

Application: Cold recycled bitumen bound material with foamed bitumen binder(Foamix®).

Material: Recycled asphalt.

Amount used: 150m3

Date: November - December 2004.

Client: Hampshire County Council.

Contractor: Raynesway Construction Southern Ltd (main contractor).

Foster Yeoman (cold recycled bitumen bound material).

Specification: Specification for Highway Works.

SummaryCold recycled bitumen bound material with a foamed bitumen binder (Foamix®) has been usedextensively in highway and footway works in Hampshire as it enables the use of recycled asphaltfrom other projects and saves energy compared to conventional hot asphalt.

This project was undertaken as part of the term maintenance programme. It was trying to push theboundaries towards a new way of using Foamix® in footways. Normally a full surface coursewould have been placed, but in this case a surface dressing was laid on top of the Foamix®instead. The B3047 at Martyrs Worthy was chosen for its rural location as a suitable test area.

The existing footway surfacing was removed along with any plant/ root damaged/ contaminatedsub-base. The footway was overgrown and significant clearing was required prior to work starting.The total length of the footway which was reconstructed was 711m. The footway was constructedto allow for a 0.08m Foamix® layer. Foamix® was also used to repair any areas where damagedsub-base had been removed. The total quantity of Foamix® used on site was 100m3 for the base/binder course and 50m3 for repairing the sub-base. A surface dressing was laid on top and the useof Foamix® in this new application was successful.

Technical benefits! The surface dressing was laid straight on

top of the Foamix®, avoiding having tolay a full surface course.

! Foamix® was used both for the base/binder course and for repairing the sub-base, avoiding the need to bring differentmaterials to site.

! Foamix® was easy to handle andavailable from the nearby depot atMicheldever.

Environmental benefits! Reuses asphalt from highway works elsewhere in Hampshire in new asphalt.

! Less energy required for cold mix material, saving in CO2 emissions.

! Saving in use of primary aggregates.

Benefits to local authoritiesThe use of recycled aggregates in this project had double benefits for Hampshire County Council.It contributed to targets under the Public Service Agreement for diversion of materials from landfilland also led to cost savings compared to conventional methods. It also demonstrated a newapplication for Foamix®, which can now be used elsewhere in the county. Recycling had directtangible benefits for the local authority as well as broader environmental and technical benefits.

Hampshire County Council Partners in Innovation (PII)

Demonstration Project 3

Recycled Surface Dressing Sweepings

BackgroundThis series of leaflets describes a number ofprojects demonstrating the technical,environmental and cost benefits that arise fromthe use of recycled and secondary aggregates inhighway works in Hampshire. Working inpartnership together, Hampshire County Council,Raynesway Construction Southern and FosterYeoman adopted sustainable policies for highwaymaintenance works. A Partners in Innovationproject, carried out by TRL and funded by theDepartment of Trade and Industry, enabled thesepractices to be captured in a number ofdemonstration projects. The material diverted from landfill as a result of the partnership is assistingHampshire County Council to meet their Public Service Agreement (PSA) target to divert anadditional 40,000 tonnes of material from landfill per annum by 2005.

Activity: Reuse of surplus surface dressing chippings.

Location: Various sites across the county.

Application: Routine highway maintenance.

Material: Recycled surface dressing chippings.

Amount used: 4,000 tonnes.

Date: 2004 ongoing.

Client: Hampshire County Council.

Contractor: Road Maintenance Services Ltd.

Specifications: Specification for Highway Works.

British Standard for Chipping Grading BS EN 13043-2002.

TRL Road Note 39, Design Guide for Road Surface Dressing.

SummaryIn surface dressing operations on highways, there are always some surplus unused materials.After the surface dressing has been laid, further surplus material is generated as sweepings ofloose material from the road surface. In Hampshire there are a number of remote sites whereunused surface dressing chippings have been stockpiled for some years. These sites are nowreceiving post surface dressing sweepings as well as the unused material. The surface dressingsweepings would previously have been sent to landfill or used on farmers’ tracks. In 2003 thesestockpiles were estimated to be in excess of 4,000 tonnes.

Hampshire County Council and their surface dressing contractor, Road Maintenance Services,developed techniques to enable the surplus chippings to be reused in further surface dressingworks. This saved the import of further high quality primary aggregates. The material came in arange of sizes including 6mm, 10mm and 14mm. It was required to be screened before it wouldbe suitable for use. A dry screening process was used to remove the majority of contaminants, andthe screened material was then lightly coated with bitumen to remove the high dust content of theresulting material.

In the 2004 season (May to August), these recycledcoated chippings were used at 33 sites acrossHampshire. In all, 1613 tonnes of 10mm materialand 1554 tonnes of 6mm material were laid usingeither a 10/6mm racked in dressing or 10/6mmdouble dressing specification. To date, all sitestreated using the recycled chippings areperforming well. Monitoring is continuing every6 months. Following the overall success of thetrials, preparations are underway for a similarprogramme in 2005.

Economic benefits! Cost of recycled surface dressing chippings: £66,479

! Value of equivalent primary aggregate chippings: £94,530

! Savings using recycled surface dressing chippings: £28,051

The cost savings illustrated here largely arose because of the long haulage distance for the equivalentprimary material and the surface dressing sweepings having no value.

Environmental benefits! The use of the locally sourced recycled surface dressing sweepings saves on the

environmental impacts of haulage of equivalent primary aggregates.

! The reuse of the surface dressing sweepings prevents their disposal to landfill andavoids the use of primary aggregates.

Benefits to local authoritiesThe use of recycled aggregates in this project had double benefits for Hampshire County Council.It contributed to targets under the Public Service Agreement for diversion of materials from landfilland also led to cost savings compared to the use of primary aggregates. Recycling had directtangible benefits for the local authority as well as broader environmental and technical benefits.

Hampshire County Council Partners in Innovation (PII)

Demonstration Project 4

Bar End Household Waste Recycling Centre

BackgroundThis series of leaflets describes a number ofprojects demonstrating the technical,environmental and cost benefits that arise fromthe use of recycled and secondary aggregates inhighway works in Hampshire. Working inpartnership together, Hampshire County Council,Raynesway Construction Southern and FosterYeoman adopted sustainable policies for highwaymaintenance works. A Partners in Innovationproject, carried out by TRL and funded by theDepartment of Trade and Industry, enabled thesepractices to be captured in a number ofdemonstration projects. The material diverted from landfill as a result of the partnership is assistingHampshire County Council with their Public Service Agreement (PSA) target to divert an additional40,000 tonnes of material from landfill per annum by 2005.

Activity: Use of recycled and secondary aggregates in the construction of a newhousehold waste recycling centre and access road.

Location: Bar End Industrial Estate, Winchester.

Applications: General fill, capping, sub-base, structural backfill, cold recycled bitumenbound base & binder course, coarse aggregate for fibre reinforcedconcrete

Materials: Recycled asphalt, recycled aggregate, recycled railway ballast,incinerator bottom ash aggregate.

Date: June - December 2004.

Client: Hampshire County Council.

Contractor: Natta Building Company (main contractor).

Foster Yeoman (cold recycled bitumen bound material).

Onyx (incinerator bottom ash aggregate).

Cemex (concrete).

Valetta (surfacing contractor).

Designer: Hampshire County Council.

Specification: Specification for Highway Works and TRL Report TRL611.

SummaryHampshire County Council wished to build a new household waste recycling centre forWinchester on a previously developed site at Bar End. The use of recycled aggregates wasmaximised as part of the design philosophy. Hampshire County Council wanted the project tobe an example of how the council should work on future developments. As a result, recycledand secondary aggregates were used in a number of applications, including high valueapplications such as asphalt and concrete.

Demolition material from the previous development was reused in the works. Other recycled andsecondary aggregates were imported as necessary. Incinerator bottom ash aggregate from a localwaste-to-energy plant was used as coarse aggregate in the base and binder layers of the accessroad. Recycled aggregates were used in the concrete base slab for the centre. The site includes anumber of other sustainability features including a sustainable urban drainage system (SUDS).

Technical benefits! The maximum use of material already on

site minimised the overall import ofaggregates to the site.

! The recycled and secondary aggregatesperformed as well as primary aggregatesin all applications.

! High value use of incinerator bottom ashaggregate in asphalt and recycledaggregate in concrete.

Environmental benefits! Minimises use of primary aggregates and

disposal of materials to landfill.

! Less energy required for cold recycledbitumen bound material compared toconventional hot asphalt, saving in CO

2

emissions.

! Demonstrates beneficial use forincinerator bottom ash aggregate.

Benefits to local authoritiesThe use of recycled aggregates in this project haddouble benefits for Hampshire County Council.It contributed to targets under the Public Service Agreement for diversion of materials from landfilland also led to cost savings compared to conventional methods. It also demonstrated that recycledand secondary aggregates can be successfully used in a number of applications, including highvalue ones. Recycling had direct tangible benefits for the local authority as well as broaderenvironmental and technical benefits.

Hampshire County Council Partners in Innovation (PII)

Demonstration Project 5

A3 Bus Priority Corridor

BackgroundThis series of leaflets describes a number ofprojects demonstrating the technical,environmental and cost benefits that arise fromthe use of recycled and secondary aggregates inhighway works in Hampshire. Working inpartnership together, Hampshire County Council,Raynesway Construction Southern and FosterYeoman adopted sustainable policies for highwaymaintenance works. A Partners in Innovationproject, carried out by TRL and funded by theDepartment of Trade and Industry, enabled thesepractices to be captured in a number ofdemonstration projects. The material diverted from landfill as a result of the partnership is assistingHampshire County Council with their Public Service Agreement (PSA) target to divert an additional40,000 tonnes of material from landfill per annum by 2005.

Activity: Construction of A3 bus priority corridor.

Location: Portsmouth to Clanfield.

Application: General fill, unbound sub-base, capping, lower trench fill.

Material: Recycled asphalt (road planings), recycled concrete aggregate (crushedkerbs), subsoil.

Amount used: 3,900 tonnes.

Date: April 2002 to May 2005 (project ongoing, expected completion dateApril 2007).

Client: Hampshire County Council.

Contractor: Dyer and Butler.

Designer: Hampshire County Council Engineering Consultancy; Atkins.

Specification: Specification for Highway Works.

SummaryThe A3 bus priority corridor project was included in Hampshire County Council’s Local TransportPlan 2001-06. The project is managed under a Local Authority and bus company partnership andis designed to provide residents with the choice of a reliable, convenient and safe service as analternative to using a car.

The works affect a 12 km stretch of road from Portsdown Hill to Clanfield and involve roadwidening and carriageway and footway reconditioning. Some of the existing wide verges werereallocated for the bus lane. At the project inception point, Hampshire County Council adopted apreference towards using recycled materials. The contractor therefore used the road planingsgenerated by the works in the capping layer of the widened road, in the sub base for the footpathsand as trench fill material. The existing kerbs were crushed using a low noise, non-invasive machineand used as a gravel type material to form the sub base of the resurfaced footways. Topsoil andsubsoil were also recovered and reused, with anysurplus being diverted to other Dyer and Butlerworks. A long-lived surface dressing was appliedto minimise the disruption which would otherwisebe caused by resurfacing works in the future.

‘Material Use Sheets’ were trialled in this project.The information gathered allows linking of surplusmaterials from one site to another and reduces theneed for primary aggregate. The project is over halfway through and shown to be embracing the goalsof sustainable development. New practices arebeing developed, which will be used in other HCCprojects to promote recycling and best practice.

Technical benefits! The reuse of materials generated in-situ minimised the need to import primary

aggregates and reduced haulage costs.

! The road planings were used successfully in capping and sub base layers and astrench fill material.

! Introduction of Material Use Sheets extended the possibilities of recycling at othersites within the county.

Environmental benefits! Reduction in use of primary aggregates and waste disposed to landfill.

! Reduction in noise by use of low noise crusher for the concrete kerbs.

! Use of more durable surfacing reduces future disruption and gives better whole lifecost for the project.

Benefits to local authoritiesThe use of recycled aggregates benefited Hampshire County Council in two ways. It contributedto targets under the Public Service Agreement for diversion of materials from landfill (3,900tonnes to date) and also led to cost savings (£87,000) compared to conventional methods. Wholelife costing enabled the use of more durable surfacing and material use sheets enabled surplusmaterials to be used elsewhere in the county. Recycling had direct tangible benefits for the localauthority as well as broader environmental and technical benefits.

Hampshire County Council Partners in Innovation (PII)

Demonstration Project 6

North Popley Development

BackgroundThis series of leaflets describes a number ofprojects demonstrating the technical,environmental and cost benefits that arise fromthe use of recycled and secondary aggregates inhighway works in Hampshire. Working inpartnership together, Hampshire County Council,Raynesway Construction Southern and FosterYeoman adopted sustainable policies for highwaymaintenance works. A Partners in Innovationproject, carried out by TRL and funded by theDepartment of Trade and Industry, enabled thesepractices to be captured in a number ofdemonstration projects. The material diverted from landfill as a result of the partnership is assistingHampshire County Council with their Public Service Agreement (PSA) target to divert an additional40,000 tonnes of material from landfill per annum by 2005.

Activity: Access road for new school on greenfield site.

Location: North Popley, Basingstoke.

Application: Cement bound sub-base, cement bound trench backfill, general fill, coldrecycled bitumen bound base.

Material: Chalk, recycled asphalt.

Amount used: 1000 m3 chalk; 300 m3 asphalt.

Date: May to June 2005.

Client: Hampshire County Council Estate Practices.

Contractor: Mildren Construction Ltd (main contractor).

Envirosoil Ltd (stabilisation).

Bardon Aggregates (surfacing).

Foster Yeoman Limited (cold recycled bitumen bound material).

Designer: Hampshire County Council Engineering Consultancy.

Specification: Specification for Highway Works and TRL Report TRL611.

SummaryNorth Popley is a new, mixed development site near Basingstoke, comprising residential units, aschool and sports facilities. The site owners, Hampshire County Council, are carrying outpreliminary infrastructure works to provide a spine road and services across the site. Contract 1of the works entailed constructing 250m of 6.1m wide single carriageway access road and footwaysfor a new secondary school.

The site is underlain by chalk, and it was decided to stabilise this by the addition of 2% ordinarycement to form cement bound sub-base. The contractor, Envirosoil, treated a 225 mm thickness ofchalk in situ using rotovating plant (picture on previous page). Cement stabilised chalk was alsoused as sub-base for 200m of footway and as backfill in trenches for the drains, but in these instancesthe chalk was excavated, treated ex-situ and compacted into place. The chalk above sub-base levelwas excavated and reused as general fill. In all, over 1,000 m3 of chalk that would otherwise havebeen disposed to landfill and replaced withimported aggregates was retained on site.

The asphalt pavements for the access roads wereconstructed using a 250 mm layer of cold recycledbitumen bound material with foamed bitumen(Foamix®) (picture below). As Foamix® is laidcold, it results in energy savings compared withconventional hot asphalt. The recycled asphaltcame from maintenance works on the A325 atAlice Holt. The Foamix® was overlain with a55mm binder course and a 45 mm hot asphaltsurface course. A total of 300 m3 of Foamix® wasused in the access road.

Technical benefits! The reuse of materials in situ minimised transport and material costs.

! The use of Foamix® reduced energy costs.

! The recycled materials performed as well as primary materials.

Environmental benefits! Reduction in use of primary aggregates.

! Reduction in waste being disposed to landfill within the county.

! Surplus asphalt planings from another site were successfully recycled.

! Reduction in lorry movements and energy.

Benefits to local authoritiesThe use of recycled aggregates in this project had double benefits for Hampshire County Council. Itcontributed to targets for diversion of materials from landfill and also led to cost and energy savingscompared to conventional methods. The use of in situ stabilisation significantly reduced lorrymovements and associated disruption on the narrow local access roads. Having been shown to besuccessful on this small preliminary contract, stabilisation and Foamix® can be used on a muchlarger scale on the spine road for the whole North Popley Development. Recycling had direct tangiblebenefits for the local authority as well as broader environmental and technical benefits.

Appendix B – 1

Appendix B: Demonstration projects: full case studies

Appendix B – 2

Appendix B – 3

Demonstration Project 1: Embankment stabilisation on A325 at Alice Holt

Construction project: Road building

Application: Selected granular fill

Product: Class 6F5 Selected granular material (coarse grading)

Material: Recycled aggregate

Region: South East

Title: A325 Major Maintenance Alice Holt Embankment Fill

Date: September 2004 to January 2005

Client: Hampshire County Council

Contractor: Raynesway Construction Southern Ltd (RCS)

Designer: Hampshire County Council

Recycled aggregate suppliers:

Wessex Construction Ltd

Day Aggregates

TJ Aggregates

Specification: Specification for Highway Works, May 2004 amendments

Conditions of contract: ICE 7th edition

Background

This project is a major maintenance scheme contracted out from Hampshire County Council (HCC). The project is a threephase operation with RCS being involved at present in phase two, which involves the stabilisation of the A325 near AliceHolt. The project is working on the section of the A325 between the junction of the B3006 at Sleaford and north to thecounty boundary at Holt Pond, a distance of about 1.8km.

There are three sections of road requiring stabilisation of the embankment. The first section is 300m long on one side ofthe road. The second section is 150m long on both sides of the road and the third section is 400m long on one side of theroad. One area requiring stabilisation was restricted in size by the presence of an area of archaeological importance. At thisarea gabion baskets were used to stabilize the embankment. The gabion baskets were filled with limestone, but to create asteep slope some recycled aggregate was used as backfill to the gabions.

The embankment was made up of poor quality clay at a variable slope and had been suffering from instability. Theembankment was dug out in benches. The material that has been removed from the site was due to be laid on a localfarmer’s field. Unfortunately this was not possible because the wet weather made the field too slippery for vehicles totravel easily. Approximately 9,000 tonnes of material was removed during the excavation of the existing embankment andthis was disposed of at a local landfill site.

The excavated material was replaced with Class 6F5 selected granular fill to the same profile (see Figure 1). Theembankment ranges from 0.8m to 5.0m in height and the works required a total of 29,000 tonnes of imported fill. The newembankment was built at a uniform slope of 1:3. The imported fill was supplied by recycled aggregates derived fromprocessing construction and demolition material from Day Aggregates Ltd and TJ Transport from Selborne, thus avoidingthe use of primary aggregates.

The area has an ancient Roman monument at the southern end of the site so when the area was being excavatedprocedures were put in place to protect the archaeological site.

The resurfacing works were carried out by Hanson PLC in December 2004 and January 2005. 160mm of road surfacewas planed off and sent to Foster Yeomen’s (FY) Micheldever plant for processing into Foamix®. The road was thensurfaced with hot rolled asphalt. All of the surfacing work took place overnight with the road being shut for 4 weeks.

Technical benefits

The recycled aggregates are a suitable material to be used as general fill. The specification called for Class 6F5 selectedgranular fill, which is normally used as a coarse grained capping layer, rather than Class 1A general granular fill. This wasto ensure a well graded granular material with a high angle of internal friction was used. The recycled aggregates met thisspecification and performed as well as primary aggregates.

Appendix B – 4

Cost benefits

There were cost savings for this project by using recycled aggregate rather than the primary aggregates. The savingslargely arose because of the difference in haulage costs. The primary aggregates would have had to travel from theMendips whereas the recycled aggregates were supplied from a local source. The cost savings that were made by using therecycled aggregates were passed onto the client to help secure the contract.

Environmental benefits

The environmental benefit of this project was a reduction in the quantity of primary material used because the embankmentwas replaced with recycled aggregate. This reduces overall waste within the county by using material that would otherwisebe disposed to landfill. There were also savings in transport distances by using a local supply of recycled aggregates.

The road planings were taken to FY’s plant at Micheldever for recycling into cold recycled bitumen bound material.This diverted a material that would normally be disposed to be made into a useful product.

New 1:3 slope being constructed

Existing soft clay fill

removed

Steps dug out from existing embankment

ROAD

Existing slope

Backfill of 6F5 material

Embankment height varies from 0.8m to 5m high

Figure 1 Showing the works carried out at Alice Holt

Plate 1 Embankment fill at Alice Holt

Appendix B – 5

Supply chain

The use of recycled aggregates on this project was promoted by RCS. They wanted to use the recycled aggregates to savecosts and transport distances of the material. There were no objections from the contractor about using the recycledmaterials.

Regulatory issues

The area at the southern end of the site falls into a site designated as a Scheduled Ancient Monument with importantRoman remains present. Consultation with the English Heritage to obtain a Scheduled Monument Consent to allow workoff the carriageway to be carried out was required.

The design specification showed that 6F2 material was to be used as fill to the embankment. This is a coarse grainedcapping material. However, in the 2004 amendments to the Specification for Highway Works new categories wereintroduced for capping materials imported to site. For the material to be classed as 6F2 material it would have to beproduced on site. There was no material available on site which could be classed as 6F2 material so it sourced elsewhere. Ifthe material was to be brought onto site then it would have been classed as 6F5 material which is required to meet slightlydifferent specifications. The permitted constituents are slightly different from Class 6F2; in particular, recycled asphalt isnot permitted in Class 6F5 but is permitted as up to 50% in Class 6F2. This has caused some confusion between the client’srepresentative, the contractor and the supplier, with additional testing being required to meet the new specificationrequirements.

Details of parties

ClientHampshire County Council - Highways MaintenanceContact: Andy HardingThe CastleWinchesterHantsSO23 8UD

Tel: 01962 847787

Email: andy.harding@hants.gov.uk

ContractorRaynesway Construction Southern LtdContact: Lloyd AllanPartnership HouseMoorside RoadWinchesterSO23 7RX

Tel: 01962 873731

Email: Lloyd.allen@raynesway.com

Appendix B – 6

Demonstration Project 2: Recycled asphalt in footway works on B3047 at MartyrWorthy

Construction project: Footways

Application: Bitumen bound base (roadbase)

Product: Cold recycled bitumen bound material

Material: Recycled asphalt

Region: South East

Title: B3047 Martyr Worthy footway works

Date: November to December 2004

Client: Hampshire County Council

Contractor: Raynesway Construction Southern Ltd (RCS)

Designer: Hampshire County Council

Cold recycled bitumen bound material supplier:

Foster Yeoman Limited (FY)

Specification: Specification for Highway Works

Background

Hampshire County Council (HCC) has a contract for all of the necessary repairs on the roads within the county called theTerm Maintenance Contract. This does not include motorways or the trunk road network. Alongside the Term Contract areseparate major works carried out within the county, these are awarded on a case by case basis. HCC has formed apartnership with RCS and FY for the Term Maintenance Contract. RCS are also involved with some of the majormaintenance works within Hampshire.

HCC signed a Public Service Agreement (PSA) with the government in April 2002 which is effective until March 2005.The PSA requires HCC to achieve more demanding performance targets than would otherwise be expected. One of thetargets was to divert up to 40,000 tonnes per annum of household, commercial and industrial waste from landfill throughthe Hampshire Natural Resources Initiative by 2005. To achieve this target a working group was set up includingindividuals, community groups, commerce and industry. RCS and FY have been involved in the PSA Working Group andare committed to recycling within Hampshire.

The following case studies are based on the work that they have been undertaking over the period June 2004 toMarch 2005.

Cold recycled bitumen bound material (Foamix®)

One of the ways in which the partnership has been pursuing sustainable construction methods is by the use of cold recycledbitumen bound material with foamed bitumen as the main binder, commonly known as Foamix®. RCS and FY have beenusing Foamix® in a number of different applications throughout the county. They expect to have used approximately12,000 tonnes by the end of the period. They spent time during the summer months experimenting with Foamix® andtrying different applications. They have used Foamix® in footpaths, road maintenance and on private driveways. Theyhave found that the Foamix® works well if laid in dry conditions but does not work so well if laid in wet weather. TheFoamix® remains stable once it has been laid for a couple of days before rain, but it is better if a sealing layer is put on top.They have found the Foamix® to perform well and are growing in confidence in using it for a variety of differentapplications. They have been using the Foamix® a lot in haunching applications all over the county. It has been used as analternative to the sub base, base and binder courses of roads and footways.

Figures 1 and 2 show how the Foamix® has been used in different road types to replace traditional materials. It ispossible to use different quantities of Foamix® depending on the volume of traffic using the road. Figure 1 shows thereduced volume of material required in building a classified road when Foamix® is used compared with primary materialsand Figure 2 compares the materials needed for a B road using Foamix®.

RCS have been keeping a record of what happens to all of the material they remove from the roads under their TermMaintenance Contract. A summary of the main material flows is shown in Figure 3. Some of the material was reprocessed

Appendix B – 7

Normal Classified road Classified road using Foamix

40mm surface course

60mm binder

40mm surface course

60mm binder

150mm road base210mm Foamix

200mm sub-base

B road using primary aggregrates B road using Foamix

100mm surfacing40mm surface course

60mm binder

200mm road base275mm Foamix

150mm sub-base

Figure 1 Showing the layers found in a normal classified road and a classified road using Foamix®

Figure 2 Showing the layers of B roads using primary aggregates and the layers using Foamix®

Foster YeomanFoamix plant Road maintenance

and new construction

Others

RCS Routine Maintenance Road Works

Waste material dug out

Landfill

Recycled Materials Supplier

Major Maintenance Schemes: Road material removed

Maintenance of Farmers' tracks Other users

Can be counted in the PSA

Inputs of material

Not counted under PSA

Figure 3 Showing the material flow from RCS works and the savings that can be counted towards the PSA

Appendix B – 8

by Wessex Construction and then re-used by others or by RCS, who estimate that for every lorry load of waste materialthey take to Wessex for processing they take a lorry load of processed material back. Some of the waste material that wasremoved during road maintenance went to FY’s Foamix® plant. Some of the Foamix® produced there was then used byRCS when carrying out road maintenance. Other waste material removed during road maintenance went straight to farmsand was used on farm tracks, with the remaining material going to landfill.

RCS are also involved in a major maintenance scheme at Alice Holt on the A325 near Farnham. This is not part of theTerm Maintenance Contract and so the material has been tracked separately. RCS is taking over 18,000 tonnes of recycledmaterial from a variety of sources that has been regularly sampled and approved for construction of new embankments.

B3047 footway works at Martyr Worthy

This project is being undertaken as part of the Term Maintenance programme. It is trying to push the boundaries towards anew way of using Foamix® in footways with a surface dressing laid straight on top of the Foamix®. The B3047 has beenchosen for its rural location which will not be used as frequently as an urban area and so makes it ideal for using as a testarea (shown in Plate 1).

The project has been used to trial the use of Foamix® in the layers up to binder course with surface dressing instead of afull surface course laid on top of it. The existing footway surfacing was removed along with any plant/ root damaged/contaminated sub-base. The footway was overgrown and significant clearing was required prior to starting work. The totallength of the footway constructed was 711m and allowed for a 0.08m Foamix® layer. The Foamix® was also used torepair any areas where damaged sub-base had been removed. The total quantity of Foamix® used on site was 150m3

broken down to 100m3 for the surface layer and 50m3 for repairing the sub-base. The area treated was large enough tomonitor whether laying surface dressing straight on top of the Foamix® was successful.

One of the contractor’s concerns was that when the Foamix® is laid it generally does not produce a smooth finish,therefore if the surface dressing is laid on top the overall finish may not be as smooth as with a normal surface course. Thismight also result in problems with ponding.

The site was visited a couple of days after the Foamix® was laid and the surface appeared satisfactory (see Plates 2and 3). The scheme proved very successful, with the quality of the finished product being comparable with that ofconventional construction.

Conclusions

RCS estimate that over the period June 2004 to April 2005 they will have used 12,000 tonnes of Foamix® in Hampshire.They will also have used approximately one lorry load of recycled aggregate produced at Wessex Constructionreprocessing plant for every lorry load of waste material removed during maintenance work and taken to the reprocessingplant. RCS have used Foamix® in different applications across the county to determine if it functions effectively andperforms well. They have found the Foamix® to be a very good product which works well in dry weather.

The use of recycled aggregates and Foamix® reduces the demands on primary aggregates and reduces the quantity ofwaste going to landfill. RCS have aided HCC in meeting their public service agreement by using recycled and secondarymaterials in their construction works.

Plate 1 The Martyr Worthy footway prior to laying Foamix®

Appendix B – 9

Plate 2 Close up of surface at Martyr Worthy

Plate 3 Completed footway at Martyr Worthy

Appendix B – 10

Details of parties

ClientHampshire County Council - Highways MaintenanceContact: Andy HardingThe CastleWinchesterHantsSO23 8UD

Tel: 01962

Email: andy.harding@hants.gov.uk

ContractorRaynesway Construction Southern LtdContact : Lloyd AllenPartnership HouseMoorside RoadWinnalWinchesterSO23 7RX.

Tel: 01962 873731

Email: Lloyd.allen@raynesway.com

Cold recycled bitumen bound material supplierFoster Yeoman LimitedContact: Martin DudleyMarston HouseMarston BigotFromeSomersetBA11 5DU.

Tel: 01373 451001

Email: martin.dudley@foster-yeoman.co.uk

Appendix B – 11

Demonstration Project 3: Recycled surface dressing chippings

Construction project: Pavements - roads, car parks, etc.

Application: Bitumen bound surface course

Product: Aggregates for bituminous materials (surface course)

Material: Recycled surface dressing chippings

Region: South East

Title: Reuse of surplus surface dressing chippings

Date: 2004

Client: Hampshire County Council

Contractor: Road Maintenance Services Ltd

Designer: Hampshire County Council

Recycled aggregate supplier:

Road Maintenance Services Ltd

Specification: Specification for Highway WorksBritish Standard for Chipping Grading BS EN 13043-2002Surface dressing work in accordance with TRL Road Note 39,Design Guide for Road Surface Dressing.

Background

In surface dressing operations on highways, there are always some surplus unused materials. After the surface dressing hasbeen laid, further surplus material is generated as sweepings of loose material from the road surface. In Hampshire thereare a number of remote sites where unused surface dressing chippings have been stockpiled for a number of years. Thesesites are now receiving post surface dressing sweepings as well as the unused material. The surface dressing sweepingswould previously have been sent to landfill or used on farm tracks. In 2003 these stockpiles were estimated to be in excessof 4,000 tonnes.

Hampshire County Council and Road Maintenance Service Ltd (RMS) wanted to find a use for the excess surfacedressing chippings and sweepings. The material came in a range of sizes including 6mm, 10mm and 14mm. The materialrequired screening before it would be suitable for use. Some investigations had already taken place into cleaning thechippings but at the time it was found that the washing facilities required and transport costs made this option uneconomic.There have since been developments in the screening processes to allow the water to be re-used, and this option will bereconsidered in the future.

RMS suggested using a dry screening process to remove the majority of contaminants. The screened material would thenbe lightly coated with bitumen to bind the high dust content of the resulting material to the aggregate, thus reducing thedust problem. This process was trialled by RMS at their depot in Cheshire. The material was screened, coated with bitumenand laid successfully as a surface dressing.

An agreement between Hampshire County Council and RMS was established so that any savings that were made wouldbe put straight back in to undertaking additional works. Stockpiled material was transported, where necessary, to strategicsites around the county and after purchasing the necessary screening equipment RMS started to screen the chippings in theautumn of 2003. While this activity was being undertaken RMS developed the plant necessary to coat the chippings.

Programme

In May to August 2004, these recycled coated chippings were used at 33 sites across Hampshire. In all, 1,613 tonnes of10mm material and 1,554 tonnes of 6mm material were laid using either a 10/6mm racked in dressing or 10/6mm doubledressing specification.

The resistance to skidding of aggregates used in surface dressings is measured by the Polished Stone Value (PSV) test.The required value of PSV for any site depends on a number of factors, including the anticipated traffic load and thegeometry of the road. The higher the PSV, the greater the skid resistance. Due to the mix of chippings prior to thescreening process, the Polished Stone Value (PSV) of the resultant material could only be assumed as 60 PSV for the

Appendix B – 12

10mm and 55 PSV for the 6mm chippings. As a number of the sites where the material was to be laid required a PSV of 65the use of the recycled material needed to be carefully managed. In some cases where double dressings were being used, itwas possible to coordinate use of the 10mm recycled chippings as the first application, with the primary 6mm layer being a65 PSV virgin aggregate. The performance of the recycled material during placement was equivalent to that expected ofprimary material.

To date all sites treated using the recycled chippings are performing well. Monitoring is continuing every 6 months,particularly related to the overall skidding resistance on site where a higher PSV primary chipping was used. Due to theoverall success of the trials, preparations are underway for a similar programme in 2005.

Facts and figures

By screening and re-screening the stockpiles the resources available were optimised as follows:

1,900 tonnes of 6mm material were recovered

2,300 tonnes of 10mm material were recovered

This material was then processed though the coating plant and stored ready for use.

Cost benefits

Cost of recycled surface dressing chippings:

Haulage costs £13,495Screening costs £32,045Coating costs £14,896Administration £ 6,043

Total costs £66,479

Value of primary aggregate chippings £94,530

Savings using recycled surface dressing chippings £28,051

The cost savings illustrated here of using the recycled materials largely arose because the long haulage distance of theequivalent primary material and the surface dressing sweepings having no initial value.

Plate 1 The dry screening of the surface dressing chippings

Appendix B – 13

Environmental benefits

The virgin materials would normally be sourced from a quarry in Wales for the higher (65) PSV material. The nearestsource of virgin material for PSV requirements of 50 is Somerset. The use of the locally sourced recycled surface dressingsweepings reduces the impact of haulage. Other environmental benefits include the avoidance of the surface dressingsweepings going to landfill and reduction in the use of primary aggregates.

Conclusions

The use of stockpiled excess surface dressing material and sweepings in Hampshire has many advantages. The material isavailable and would otherwise be used in lower value applications such as farm tracks, or sent to landfill. In Hampshire theprimary aggregate that would otherwise be used for this application would require a long haulage distance. This turn has animpact on the cost of the aggregate and is associated with an environmental burden. The material has been used on a largenumber of sites across Hampshire. The placement behaviour of the recovered material was found to be very similar toequivalent surface dressings using primary aggregate. Testing is being carried out on a 6 monthly bases on the sites wherea double dressing has been used. The PSV of these sites is being tested to ensure that it continues to meet safetyrequirements. It is currently too early to compare the PSV of the recycled material with primary aggregate over anysignificant time frame. However, due to the success of the trial so far a similar works programme is planned for 2005.

Contact details

ClientHampshire County Council – Highway MaintenanceContact: Andy HardingThe CastleWinchesterHampshireSO23 8UD.

Tel.: 01962 847787

Email: andy.harding@hants.gov.uk

ContractorRoad Maintenance Services Ltd.

Plate 2 The laid recycled surface dressings

Appendix B – 14

Demonstration Project 4: Bar End Household Waste Recycling Centre

Recycled and secondary aggregate use in the construction of a Household Waste Recycling Centre and Access Roadat Bar End Winchester

Construction project: Pavements – roads, car parks, etc.

Application: General granular fill

Capping

Selected granular fill: backfill to structures

Unbound sub-base

Concrete surface slab

Bitumen bound binder course

Bitumen bound base

Product: Class 1A Well graded granular material

Class 6F3 Selected granular material

Class 6F2 Selected granular material (coarse grading)

Class 6P Selected granular material

Type 1 Granular sub-base material

Type 4 Granular sub-base material

Cold recycled bitumen bound binder course material

Cold recycled bitumen bound base material

BS EN 12620 aggregate Grade 0/20

Material: Recycled aggregate

Recycled asphalt

Incinerator bottom ash

Spent railway ballast

Region: South East

Title: Recycled and secondary aggregate use in the construction of a Household Waste RecyclingCentre and Access Road at Bar End Winchester

Date: June 2004 to December 2004

Client: Hampshire County Council, Environment Department, Waste Management Group

Contractor: Natta Building Company

Designer: Hampshire County Council Engineering Consultancy

Recycled aggregate Onyx/ Foster Yeoman

Supplier: Local suppliers

Reused material on site

Specification: Specification for Highway Works, May 2001 amendments

Conditions of contract: ICE 7th Edition Conditions of Contract for Civil Engineering, with Foster Yeoman asnominated subcontractor for the supply of cold recycled bitumen bound material.

Summary

Hampshire County Council (HCC) wished to build a new household waste recycling centre (HWRC) to serve Winchesteron a previously developed site at Bar End. The use of recycled aggregates in the construction of the HWRC and accessroad has been maximised by the client insisting on the use of recycled materials. HCC wanted the project to be an exampleof how the council should work on future developments. The engineering consultant was involved at an early stage and

Appendix B – 15

tasked with designing recycled aggregates into the project. Specifications were adapted where necessary to enable the useof recycled and secondary aggregates. Demolition material from the previous development and car park remained on siteand was reused in the HWRC and access road. Involvement of Foster Yeoman and Onyx through other HCC initiatives ledto the use of processed incinerator bottom ash (IBA) as coarse aggregate in the base and binder layers of the access roadusing Foamix®. Foamix® is a term commonly used to describe cold lay asphalt with a binder consisting predominantly offoamed bitumen. It can be used for in situ recycling or in ex situ applications; this allows the use of other recycled orsecondary materials as the coarse aggregate, such as IBA in this case study.

Recycled aggregate and spent railway ballast were imported for use in earthworks and the concrete base slab of theHWRC was constructed using recycled aggregate as 15% of the coarse aggregate. Close liaison was maintained with theEnvironment Agency to resolve any environmental concerns or regulatory issues over the use of IBA. The projectillustrates how the use of recycled and secondary aggregates can be maximised when the client provides a clear brief, thedesigner actively specifies alternative materials, the contractor presses his suppliers to provide the required materials andthe client and contractor’s site staff work together to achieve a satisfactory quality of construction.

Background

HCC is responsible for the disposal of the waste produced by the 1.6 million residents in the county. There are 26 HWRCswithin the county, 24 of which are the responsibility of HCC. The majority were built in the 1970’s and were in need ofsome upgrading. Some required maintenance and others needed to be pulled down and a replacement built elsewhere. In2000 it was decided that a site would be needed for a new HWRC to serve the Winchester area. This was the fourth newHWRC to be built as part of this programme. The site at Bar End was owned by HCC and was a brownfield site. Thebusinesses on site had plans to move off the site in the near future so the site would be left empty. The site was chosen as anew location for the HWRC. The HWRC site is approximately 1 acre with a 300m long access road (see Figure 1).

Pond

Downwardslope

Road

Drainage

Retainingwall

Ditch leadingto River Itchen

Upper access road for publicto deposit their waste

Lower levelconcrete slab

The form of the HWRC is a circular concrete slab as the lower level, on which the containers for the recycled materialswill be placed, with concrete retaining walls rising to an upper level where vehicles will park and from where materials canbe placed in the containers. There will be a one-way road system for vehicles around this upper level. The access road runsfor 300m from the end of the public road at the edge of Bar End Industrial Estate to the HWRC. It is on sloping ground andrequired a sheet pile retaining wall on the downslope side for the first 100m from the public road. A schematic crosssection through the access road is shown on Figure 2.

As well as maximising the use of recycled aggregates, the site incorporates a number of other sustainability features.These include a sustainable urban drainage system (SUDS) that will take all the runoff from the site and the access road.All the runoff will be allowed to infiltrate into the ground through swales and a balancing pond with storage capacity forthe 1 in 100 year storm.

The client (the Waste Management Group in the Environment Department of HCC) made it clear to the Engineeringconsultancy that the project was to be a demonstration project for sustainable construction techniques. This included usingrecycled and secondary aggregates in the construction where practicable. The designer therefore specified the materials thatwere permitted and the method of treatment for site won materials to allow them to be used within the permanent works.

Figure 1 Showing site layout (not to scale)

Appendix B – 16

Within Hampshire three new incinerators are to be built by the end of 2005. This will result in approximately 100,000tonnes of IBA arising within the county which needs to be managed. It was decided to use processed IBA arising in thecounty as the aggregate in the base and binder layers of the asphalt pavement in the access road to the HWRC. A smallscale trial with IBA as aggregate in asphalt had been carried out in Hampshire in 2003, and there are examples of the use ofIBA in asphalt and concrete from elsewhere in the UK and overseas.

Surface course45mm

Sub-base(recycled aggregates)

150mm

Capping ~200mm

Foamix baseand binder

course70-300mm

SUDS

Rain

Water table0.9m-2.9m

below ground level

Existing roadstructure

160mmFoamix

FootpathKerbandgully

Figure 2 Diagrammatic cross section of access road (not to scale)

Plate 1 Stockpiled crushed pavement on site ready for use as granular sub-base

Appendix B – 17

Specification, quality assurance and design

The specification for the project is the Specification for Highway Works, incorporating the May 2001 amendments. Thesepermit the use of recycled aggregate and asphalt in a wide range of applications including general and selected granular filland unbound granular sub-base.

The engineering consultant wrote a specific design specification for each different recycled material that was to be usedon site. The method statement for the use of IBA in Foamix® was written in conjunction with FY and was based on theexperience of HCC and FY with Foamix® in a number of highway maintenance and new works projects, and the smalltrial with IBA in 2003. Foamix® is a term commonly used to describe cold lay asphalt with a binder consistingpredominantly of foamed bitumen. Foamed bitumen is produced by the injection of 1 to 2% cold water with air into hotpenetration grade bitumen. This process produces a high-volume, low viscosity fluid with low surface tension. Theseproperties enable the foamed bitumen to coat a wide range of moist, cold recycled aggregates. Foamed bitumen can beused for in situ and ex situ recycling, which allows the use of other recycled or secondary materials as the coarse aggregate.Hydraulic binders can be added to vary the properties of the asphalt product. Materials bound with foamed bitumen, on itsown or with lime and pulverized-fuel ash, are highly workable; they can be stockpiled or reworked if necessary up to 48hours after production. For an increased rate of curing, foamed bitumen can be combined with Portland cement or otherhydraulic binder. The design is based on existing guidance on the use of foamed bitumen in the Specification for HighwayWorks and recent design guidance for cold recycled bituminous materials produced by TRL as TRL Report TRL611.

Technical benefits

A number of technical benefits have arisen by using recycled aggregates on site. The demolition waste and asphalt from theexisting car parking were already on site so the crushing and grading were carried out in situ using a mobile crushing plant.

The use of recycled aggregates and recycled asphalt in the sub-base and earthworks was praised by the contractor, whostated that they were easier to lay than the equivalent primary materials. The cut-and-fill balance was designed so that asmuch of the sub-base of the existing car park as possible was used as recycled aggregate in the new works. There was arequirement for a net import of materials to the site. This was met by recycled aggregates and spent railway ballast fromlocal sources. As well as capping and unbound sub-base, these materials were used as general granular fill and as structuralbackfill to the retaining wall along the access road and the concrete retaining walls around the base slab of the HWRC. Thematerials performed very well; they met all specification and quality requirements and were easy to handle and compact.

The use of recycled aggregates in the base slab concrete caused some technical problems in the mix design which wereovercome. The concrete was fibre reinforced to prevent shrinkage cracking and incorporated 15% recycled aggregates as thecoarse aggregate in the concrete. The concrete had a compressive strength of c25/30 and a maximum aggregate size of 20mm.

The technical benefits of using IBA in Foamix® were identified by FY as being an easy material to handle which wasvery consistent in its properties. A programme of testing for the Foamix® was prepared to demonstrate that its performancewas satisfactory.

All of the works have now been completed with the Foamix® being laid in early November. The Foamix® went downvery well and there have been no problems with the strength testing that has been carried out. The project was completed toprogramme and opened on 15th December 2004.

The quantities of recycled materials used on site are shown in Table 1.

Table 1 Quantities of recycled materials used on site

Application SHW Classification Quantity

Chalk imported from adjacent park and ride scheme and rock chalk General fill 978 m3

imported from other construction sites

Planed lean-mix, bituminous planings and track ballast from other Sub-base and fill to structures 2032 m3

construction sites

Recycled aggregates Fibre reinforced concrete 17.1 m3

Processing on site-won concrete/ bituminous material 478 m3

Crushed concrete/ planings imported from other sites Class 6F capping layer beneath roads and paved areas 673 m3

Crushed concrete/ planings imported from other sites General Fill beneath roads and paved areas 672 m3

Crushed concrete/ planings imported from other sites ARRW-Class 6N/ 6P 163 m3

Crushed concrete/ planings imported from other sites Sub-base 381 m3

HWRC RW- HWRC RW- Class 6N/ 6P 361 m3

IBA Foamix® 1200t

Parapets reused from another construction site 80m

Appendix B – 18

Cost benefits

The cost benefits of this project arose because the recycled aggregates were from the demolition of the buildings and theexisting access road on the site. There were no landfill tax or aggregates levy charges to be paid because all of the materialavailable on site was reused and all the imported materials were recycled or secondary aggregates, and hence not subject tothe Aggregates Levy. This also reduced the transport cost associated with bringing primary aggregates onto site. Anothersaving identified was that the crushing machine only had to be brought onto site once. The use of the recycled materialssaved money in the sub-base and capping layers. The concrete incorporating the recycled materials cost more than ifequivalent primary materials had been used instead. There were some marginal additional costs in producing the concretedue to design trials and the additional material handling required for blending the RCA with the other coarse aggregates.

Environmental benefits

The major environmental benefit of this project was the reduced requirement for primary aggregates. In specifying that noprimary material could be used as Type 1 material on site, a large saving of primary aggregates was made. This alsoresulted in the use of the demolition material on site so that less waste was generated by this development. This in turnrequired fewer lorry movements than if all of the demolition material had to be removed and new primary aggregatesbrought onto the site.

In Hampshire three, new energy from waste plants will be operational by the end of 2005. This will generate 100,000tonnes per year of IBA which requires utilisation or disposal. This project was acting as a demonstration of how IBA canbe a useful resource in construction. If this demonstration project is successful it will provide Hampshire with analternative to landfill for IBA.

Supply chain

HCC Waste Management Group is the client for the building of the HWRC and access road. They secured the Bar End siteabout 4 years ago (2000) and drew up an outline for the scheme. They involved HCC Engineering Consultancy in 2002 todesign the HWRC and access road. HCC saw this project as an opportunity to demonstrate as many aspects of sustainableconstruction as possible. The council wanted to lead by example in using recycled materials for a HWRC, showing that itcan be done and that these perform as well as primary materials. They are hoping that by demonstrating the use of recycledaggregates in this project it will encourage the use of recycled and secondary aggregates in similar applications. If thisproject is successful they will use more recycled materials in future council projects and it will affect the way contracts areproduced. See Figure 3 for an illustration of the supply chain.

Plate 2 Base slab containing recycled aggregate concrete

Appendix B – 19

The Engineering Consultancy was tasked with incorporating the use of secondary and recycled aggregates into thedesign specification to ensure an acceptable performance. For each of the activities using recycled aggregates a materialspecific specification was included if the use of the material was not already covered by the existing specification. One ofthe major parts to the project was that no primary material was to be used for Type 1 sub-base.

In April 2002 HCC signed a Public Service Agreement (PSA) with the government for the period up to March 2005. ThePSA required HCC to achieve more demanding performance targets than would otherwise be expected. One of the targetswas to recycle 40,000 tonnes of household, commercial and industrial waste through the Hampshire Natural ResourcesInitiative. To achieve this target a working group was set up including individuals, community groups, commerce andindustry. The working group included HCC’s term maintenance contractor for highway works, Raynesway ConstructionSouthern Ltd (RCS), and the materials supplier Foster Yeoman Ltd (FY).

FY has a new mobile Foamix® plant which they were prepared to move into Hampshire so that it could be used on roadmaintenance schemes. It was recognised that a large quantity of IBA would be arising within the county. HCC set up anIBA Working Group, involving HCC, RCS, FY and the operator of the energy-from-waste plants, Onyx EnvironmentalGroup plc. It was decided that if a demonstration project using IBA as the aggregate in Foamix® could be undertaken itwould provide a useful solution for a new waste stream arising within the county. The HWRC development was on abrownfield site and it was thought that this would be an ideal place for a demonstration project.

FY helped the HCC Engineering Consultancy to develop the method statement for IBA, which was issued with thetender document. Within the design specification it was identified that the Foamix® used on site had to be supplied by FYand would contain the IBA from the Chineham energy-from-waste plant near Basingstoke. There were some concerns overthe commercial implications of this so the price of the Foamix® was fixed before the specification was sent out for tender.

The contract was put out for tender in February 2004 and was awarded to Natta Building Ltd in May 2004; workcommenced in June 2004. The site was cleared prior to work starting. Natta Building Ltd were committed to using recycledmaterials and proceeded to use the materials available on site. There were not enough recycled aggregates available on siteto carry out all of the Type 1 sub base work so additional materials were brought in by a number of different suppliers.Recycled aggregates were brought on site from local suppliers. Natta had a contract with RMC to supply them with theconcrete containing recycled aggregates for the base of the HWRC.

Figure 3 Contractual arrangements

Client

HCC Waste ManagementGroup

Designer

HCCEngineeringConsultant

Main ContractorNatta Building Company

NominatedSub-contractorsFoster Yeoman

and Onyx

Track Ballastpurchasd through

Whitchurch

Hot Rolled Asphaltsupplier

Foster Yeoman

Concretesuppliers

RMC

DesignFoster Yeoman

HCC (Technical Advice Group)PSA Working Group

andIBA Working Group

Appendix B – 20

Onyx stockpiled 1,200 tonnes of IBA at the Rainham Marshes landfill site in Essex. The IBA was weathered for at leastthree months and testing was undertaken to ensure the quality of the ash. Onyx processed the IBA to remove impurities,screened and graded the material to ensure the correct size and quality for use in the Foamix®. The processed IBA wasdelivered to the FY depot at Micheldever and mixed with the other ingredients to form the Foamix® used in the base andbinder course of the access road.

The project has proceeded very successfully to date and the HWRC opened on 15 December 2004. The projectillustrates the benefits of a collaborative approach, whereby various departments within HCC and other parties in the PSAand IBA Working Groups interacted positively to suggest possibilities and overcome potential obstacles. The strong leadgiven by HCC on sustainability and working in partnership set the tone for the whole project.

Plate 3 Foamix® being laid at the HWRC

Regulatory issues

The major regulatory issue for this project was gaining planning permission for the development on the site initially; noknown problems or issues have been raised. This was agreed before the project became a demonstration project.

The use of Foamix® containing IBA was an issue of concern to the Environment Agency (EA), because a ditch at theedge of the site leads to the River Itchen which is a candidate Special Area of Conservation under the Habitats Regulationand therefore has a high level of protection. The EA required further investigation to be carried out to identify the risks, ifany, of using the IBA within the Foamix®. Viridis carried out a qualitative risk analysis to identify any risks that the use ofIBA at the site might cause. It was found that the risk of the IBA causing harm to human health or the environment wasvery low. A programme of leaching tests and environmental monitoring was agreed by all parties to ensure that the use ofIBA in Foamix® did not pose any risk to the environment.

The extensive testing of the IBA prior to use, preconditioning and the mixing into the Foamix® meant that the IBA wasno longer classed as a controlled waste. The Bar End site was not therefore considered to require a Waste ManagementLicence or exemption to receive the Foamix®.

Conclusions

This case study has shown how a number of different recycled and secondary aggregates can be used in a constructionproject with the same efficiency as if primary aggregates had been used. This case study has shown that constructionprojects can be influenced by the client and that specifying the use of recycled and secondary aggregates at the beginningof the project can have a beneficial effect. The importance of having all stakeholders in the project involved in using therecycled aggregates has been illustrated by the success of this project. If one party is not committed to using the recycledand secondary aggregates it can influence the cost and quality of material that is supplied.

Appendix B – 21

The specification for the Foamix® used on site had to be supplied by HCC and FY to ensure that it included the use ofIBA from Chineham energy-from-waste plant. This was an unusual specification but has allowed the case study to showthe application of a large quantity of IBA in Foamix®. The Foamix® was laid at the beginning of November 2004 withmany interested parties visiting the site to see the operation. The project has already been a success in raising the awarenessof using recycled aggregates in construction, which was demonstrated by the number of visitors who made the trip to thesite to see the Foamix® being laid. It will hopefully encourage other contractors to use IBA in Foamix® with confidence.

Details of parties

Hampshire County CouncilEnvironment Division - Waste ManagementDavid WardThe CastleWinchesterHampshireSO23 8UD

Tel: 01962 847021

Hampshire County CouncilEngineering ConsultancySimon FryerThe CastleWinchesterHampshireSO23 8UD

Tel: 01962 847753

Environment AgencyPeter KellyColvedene Court, Wessex WayColden CommonSO21 1WP

Tel: 01962 764935

Onyx SELCHP LtdPeter LewisLandman Way, Off Surrey Canal RoadLondonSE14 5RS

Tel: 020 7394 4782

Foster Yeoman LtdMartin DudleyMarston House, Marston BigotFromeSomersetBA11 5DU

Tel: 01373 451001

Appendix B – 22

Demonstration Project 5: A3 Bus Priority Corridor, Portsmouth to Clanfield

Construction project: Pavements – roads, car parks, footways etc.

Application: General fill

General granular fill

Unbound sub-base

Capping

Lower trench fill

Re-grading landscape areas

Shrub and tree planting

Bus lane surface course

Product: Class 1A well graded granular material

Class 1B uniformly graded granular fill

Type 1 unbound sub-base mixture

Class 2C/2D general fill

Class 5A/5B Topsoil

Class 6F3 selected granular material

Class 8 miscellaneous fill

Material: Recycled Asphalt (road planings)

Recycled concrete aggregate (crushed kerbs)

Class 2C/2D/5A/5B recycled as general fill

Region: South East

Title: A3 Bus Priority Corridor

Date: 2002-2008

Client: Hampshire County Council, Implementation

Contractor: Dyer and Butler

Designer: Hampshire County Council, Engineering Consultancy and Atkins Consultantproviding design resource support

Recycled aggregate supplier: n/a

Specification: Specification for Highway Works

Contract: ICE 5th edition Conditions of Contract

Background

By 2020 it is predicted that there will be a 40% increase in road traffic, so alternative transport solutions are needed toensure that busy urban areas do not become gridlocked. Councils throughout the country are being given tough targets bythe Government to increase public transport use, reduce congestion and increase housing. In meeting housing targets, atransport infrastructure must be provided that can accommodate growing numbers of residents.

Designed with the future in mind, the A3 Bus Priority Corridor Project is included in Hampshire County Council’s(HCC) Local Transport Plan 2001-6. It is managed under a partnership between HCC, Portsmouth City Council (PCC),Havant Borough Council (HBC), East Hampshire District Council (EHDC) and the bus operator First.

The A3 Bus Priority Corridor will provide high quality, reliable public transport by offering passengers a priority busservice along the A3 corridor from Gunwharf Quays, Portsmouth to Clanfield, a village north of Horndean. Reliable, safe,clean and timely, the service will represent a realistic alternative to the car, helping to reduce the thousands of car journeysmade into and out of Portsmouth every day.

The new service has been branded ‘ZIP’, and a fleet of distinctive, new-look buses in the white, purple and green ZIPlivery are already in use along the route.

Appendix B – 23

South of Portsdown Hill , PCC are gradually completing bus priority improvements to the corridor. North of PortsdownHill, the team lead by HCC is building the route in five sections:

Section 1 - Portsdown Hill to Purbrook.

Section 2 - Purbrook to Waterlooville.

Section 3 - Waterlooville Town Centre.

Section 4 - Waterlooville to Cowplain.

Section 5 - Cowplain to Clanfield.

The works affect a 12km long stretch of road and involve road widening, carriageway and footway reconditioning,diversion of statutory undertakers’ utilities, drainage, replacement street lighting and new/upgraded pedestrian crossings(puffins and toucans). Priority is given to buses over other traffic at junctions and where bus lanes end. For bus passengersthe project includes the provision of high quality bus shelters designed for accessibility needs, real-time travel informationand help points linked to a new network of CCTV cameras.

The scheme includes accommodation works affecting local shops, churches and some residential properties adjacent tothe scheme, so that the project is a benefit for the local community. Where appropriate it includes improvements beyondthe highway boundary to help mitigate the impact of any road works and to integrate them with other local features andfacilities. With the agreement of the landowner, the works can involve things such as resurfacing of driveways or footways,installing new fences, providing off-street parking, rear service roads for deliveries, paving, soft landscaping and othergeneral environmental enhancements.

Programme

Due to the length of the works the project has been split into 5 main sections as illustrated in Table 1 and some of thesections have been split further into sub-sections. The work was originally programmed to take place over a 5 year periodbut due to funding constraints it will now take 6 to 7 years.

Design, specification and quality submission

To ensure the project is delivered in a sustainable way a best practice checklist with supporting tools is under development.Currently only being used in-house on a few trial schemes, the checklist and tools are intended to be cascaded to othersections in the Environment Department at HCC.

The checklist is based upon HCC’s 12 themes of sustainable development. It is a project based audit form recordingprogress and development of best practice to ensure the project is sustainable for the full life of the scheme.

The supporting tools include Material Use sheets which are to be completed at key project stages with.

! Preliminary design quantities.

! Detailed design quantities.

! Tender quantities.

! Start quantities.

! Completion quantities.

The record sheets split materials on a project into three categories:

! Materials on site for reuse.

! Materials on site for disposal.

! New materials required for site.

Plate 1 ‘Zip’ bus livery

Appendix B – 24

The benefits of recording this information derive from the ability to:

! Link surplus materials from one site to another.

! Reduce new material requirement.

! Promote increased lifecycle.

In addition to normal design considerations the design team paid particular attention to whole life costing. An example isthe surfacing material specified for the bus lanes. Traditionally surface dressing is specified as it is quick and inexpensiveto apply, but this wears out and has to be replaced every few years, causing disruption. For this project, a material with adesign life of 20 years was specified. In whole life costing over a 20 year period the application of a higher qualitysurfacing material instead of repeated surface dressing visits was found to be more cost effective.

‘Hardicrete’ by Miles Macadam, or an equivalent BBA approved material, was specified for the project. The product is aheavy duty surfacing material 40mm thick, with red coloured 14mm sized aggregate (min PSV 55 Max AAV 12), groutedwith bulk mixed, quality-assured, red coloured, modified resin cementitious grout.

HCC suggested in the contract documents a preference towards using recycled materials and to recycle rather thandispose of materials normally sent to landfill.

Dyer and Butler (D&B) purchased a road planing machine especially for the project. They have used the road planingsin the capping layer of the road widening, in the sub base for the footpaths and as trench fill material. The kerb crusherreduced the kerbs to a sandy gravel type material to form the sub-base of the resurfaced footways.

For section 2B, earthworks generated material suitable for landscaping and bulk fill operations. The project hasgenerated thousands of tonnes of road planings and occasionally there have been enough road planings and surplusearthworks materials to be reused on other D&B projects.

Table 1 Programme of works

Sections

Area covered Status Date of construction

Section 1Portsdown Hill to Purbrook Complete April 2002 to February 2003

Section 2APurbrook Village Maintenance period February 2004 to April 2005

Section 2BPurbrook Village to Waterlooville Maintenance period October 2004 to March 2005

Section 3AWaterlooville Forrest End Road Maintenance period October 2004 to May 2005

Section 3BForest End/ Maurepas Way roundabout and Construction May 2005 to December 2005up Rockville Drive

Section 3CWaterlooville main town centre Construction June 2005 to June 2006

Section 3DSt Georges Walk to Maurepas Way Maintenance period October 2004 to March 2005

Section 4AHulbert Road to Queens Inclosure Advanced works – Street lighting & CCTV January 2005 to December 2006

Main works – Detailed design

Section 4BQueens Inclosure Advanced works – Street lighting & CCTV January 2005 to December 2008

Main works – Detailed design

Section 4CCowplain Advanced works – Street lighting & CCTV January 2005 to December 2008

Main works – Detailed design

Section 5ACatherington Lane to Clanfield Main works – Detailed design January 2006 to December 2008

Section 5BLove Dean Lane to Catherington Lane Advanced works – Street lighting & CCTV January 2005 to December 2006

Main works – Detailed design

Section 5CCowplain to Love Dean Lane Advanced works – Street lighting & CCTV January 2005 to April 2007

Main works – Detailed design

Appendix B – 25

Facts and figures

Between April 2002 and March 2005 HCC made an undertaking to Government under the Public Service Agreement(PSA) to achieve demanding performance targets. One of the targets was to recycle 40,000 tonnes per annum of household,commercial and industrial waste though the Hampshire Natural Resources Initiative. In 2004 the A3 Bus Priority projectcontributed 3,946 tonnes to this target, as detailed in Table 2.

Other materials comprise lighting columns, bus shelters, general metalwork, illuminated and non-illuminated signs.

Plate 2 Laying Hardicrete Plate 3 Section of the bus lane

Table 2 Cost savings for recycled/reused materials

Materials on site for reuse on site or to be recycled TotalMaterial Disposal Processing scheme

2004/2005 saving saving cost cost/savingSection Material tonnage £ £ £ £

Section 2a Concrete kerbs 92 - 2,844 -937 – -3,780Planings 731 - 22,702 - 8,493 – -31,195Other materials 1 0 -10 162 152

Section 2b Concrete kerbs 176 - 5,452 -1,796 – -7,247Topsoil and subsoil 1,699 - 15,274 -19,741 38,717 3,702Planings 588 -18,261 -6,832 – -25,093Other materials 14 0 -138 2,185 2,047

Section 3 Concrete kerbs 49 - 4,622 -1,523 – -6,145Topsoil and subsoil 34 - 310 - 401 786 75Planings 463 - 14,379 -5,380 – -19,759

3,946 - 83,843 -45,250 41,850 -87,243

Cost benefits

Cost savings have been made on the project by using the road planings instead of the primary materials. Although theprimary aggregates would not incur a large transport cost as they would have been sourced from Portsmouth, a cost savingwas still made.

The kerb crusher was used on Sections 1 and 2 of the project because they are long straight sections of road. Section 3 ofthe work was split into smaller sections through the town centre so as to minimise disruption. This meant that the use of thekerb crusher was not economically viable with the limited length able to be crushed at any one time. D&B calculated thatthe kerb crusher cost £1,200 per day and that to make it economically viable they would have to crush 1000m of kerb perday. When the works progress to Sections 4 and 5 of the project it is intended to use the kerb crusher again on the longstraight stretches where it will be economically viable.

Environmental benefits

The environmental benefits of using the road planer and the planings generated on site are the reduction in lorry miles,savings in the use of primary materials and reduction in waste produced.

Appendix B – 26

The kerb crusher has lessened the disruption of removing the kerbs by providing a non invasive technique. Normallycrushing of kerbs is very noisy, but the machine used for this work operated at significantly reduced noise levels.

As part of its commitment to continually reviewing and improving its services, the First bus company increased thefrequency of Portsmouth Overground 40 and Zip 41 from Sunday 6 February 2005 to every 12 minutes on its Monday toFriday daytime services. This improvement is as a result of a steadily increasing number of passengers using these services,currently 7.4%.

Marc Reddy, Deputy Managing Director for First bus operations in Hampshire & Dorset explained, ‘The reasons for thiscontinued and sustained increase in usage are threefold: year-on-year growth in students at South Downs College,investment by Portsmouth City Council and Hampshire County Council to improve road infrastructure as part of workingquality partnerships with First, and finally a commitment by First to operate the highest quality fleet on these routes.’

Conclusions

The project is over half way through with the first two sections of work completed and the third section underway. The case studyhas shown that the A3 Bus Priority Project is embracing the goals of sustainable development and as the project proceeds it iscontinuing to develop good practices for use by its partners and for use on other Hampshire County Council projects.

The project has successfully used road planings generated from the works instead of primary aggregates with consequentcost savings and environmental benefits. The use of the kerb crusher in Sections 1, 2, 4 and 5 provides savings in waste andis a low noise non-invasive method of removing the kerbs.

Details of parties

Hampshire County CouncilImplementationGeoff ToppsThe CastleWinchesterHampshireSO23 8UD

Tel: 01962 847959

First Hampshire LtdMike SmithLondon RoadHillseaPortsmouthPO2 9RP

Tel: 023 87057 0764

Hampshire CountyCouncil Engineering ConsultancyChris MurrayThe CastleWinchesterHampshireSO23 8UD

Tel: 01962 847052

Dyer & ButlerSteve JayneMead HouseStation RoadNurslingSouthamptonSO16 0AH

Tel: 023 8074 2222

DYER & BUTLER

Appendix B – 27

Demonstration Project 6: North Popley Development, Basingstoke

Construction project: Pavements – roads, car parks, etc.

Application: General fill

Cement bound sub-base

Cement bound trench backfill

Cold recycled bitumen bound base

Material: Chalk

Recycled asphalt

Region South East

Title: North Popley Development Contract 1

Date: May to June 2005

Client: Hampshire County Council Estate Practices

Designer: Hampshire County Council Engineering Consultancy

Main contractor: Mildren Construction Limited

Stabilisation contracter: Envirosoil (Remediation) Limited

Surfacing contractor: Bardon Aggregates

Cold recycled bitumen bound material supplier: Foster Yeoman Limited

Specification: Specification for Highway Works with contract specific amendments based on TRL ReportTRL611

Conditions of Contract: Institution of Civil Engineers, 7th edition

Background

North Popley is a major new mixed use development on a green field site on the north side of Basingstoke. The site willinclude about 950 residential units, a neighbourhood centre and a new secondary school with community sports facilities.In total, about 20 ha will be developed. The site is owned by Hampshire County Council (HCC), who will run the school asthe Local Education Authority. They are carrying out preliminary infrastructure works to provide a spine road and servicesacross the site. Plots will then be sold to private developers.

Contract 1 of the project comprises improvements to the existing roads around the site, which are narrow rural roads, andinstallation of an access road and services to the site of the new school. The total length of new road is about 250m of 6.1 mwidth single carriageway. In subsequent phases the spine road will be built across the site, a distance of about 1.5 km. TheContract 1 works have to be completed by August 2005 to enable construction of the new school to start on schedule.

In accordance with HCC’s corporate policies on sustainability, opportunities are being sought to maximise recycling andthe use of recycled and secondary aggregates in the construction. Any methods that are shown to work successfully in thePhase 1A works can be extended to the much larger spine road and associated works.

Cement stabilisation of chalk

The site is underlain by chalk. It was decided at the design stage to stabilise the chalk in situ with cement to form a cementstabilised sub-base as an alternative to excavating the chalk and replacing it with Type 1 unbound sub-base. The siteinvestigation for the works had shown that the chalk above sub-base level was weak and the original design was to disposeof this material to landfill. However, when the topsoil was stripped for the Phase 1A works the chalk was found to be inbetter condition that expected. The excavated chalk was therefore retained on site and used as general fill for the footways,saving the import of 400 m3 of primary aggregates as general granular fill. The excavated chalk was classed as Class 3general fill and compacted in accordance with the requirements of the Specification for Highway Works.

Appendix B – 28

The amount of cement required to stabilise the chalk for use as cement bound sub-base was determined by laboratorytrials. Samples were taken for testing and gave the following results:

Material CBR

Untreated chalk 13%

Chalk + 2% cement 50%

Chalk + 4% cement > 100%

A California Bearing Ratio (CBR) of 30% is the normal requirement for unbound sub-base. The tests showed that thiscould be achieved with only a small addition of cement. The use of cement stabilised sub-base was therefore approved,with a requirement that the stabilised material achieved a minimum CBR of 30% by 7 days after stabilisation. A contractspecific additional clause for the Specification for Highway Works was produced by HCC to cover the stabilisation of thechalk with cement for the sub-base.

The stabilisation works were carried out by specialist contractor Envirosoil (Remediation) Limited in May 2005. A 225 mmthickness of chalk was treated in situ with 2% ordinary cement (CEM 1) using specialist rotovating plant to mix the cementinto the soil. The layer was then compacted with a vibrating roller and treated with a bituminous tack coat to prevent moisturegetting into the stabilised material. The material was tested by HCC using Clegg hammer tests to estimate the in situ CBR ofthe stabilised material. The tests gave CBR values in the range 50% to 80%, well in excess of the design requirement of 30%.

Plate 1 Cement stabilised chalk sub-base with bituminous coating to protect it from the weather

As well as the 250m of 6.1 m wide access road, cement stabilised chalk was used as sub-base for about 200m offootway. This was not treated in situ, but was excavated chalk from the site. It was mixed with 2% cement, placed andcompacted satisfactorily. Excavated chalk mixed with 2% cement was also used to backfill trenches for the drains.Untreated chalk was not suitable for this application, as it might have softened and settled on exposure to moisture.

The approximate quantities of materials used are as follows:

Material Application Quantity (m3)

Untreated chalk Class 3 general fill for footways 400

Chalk + 2% cement Class 8 trench backfill 200

Chalk + 2% cement In situ stabilised sub-base for access road 350

Chalk + 2% cement Ex situ stabilised sub-base for footways 50

Total 1,000

Appendix B – 29

As a result of these measures, 1,000m3 of chalk that would have had to be disposed of to landfill and replaced withimported aggregates were retained on site and used in the permanent works. This equates to approximately 200 lorrymovements that were saved, plus the savings in landfill space and in primary or recycled aggregate use. This more thanoffsets any environmental disbenefits from the manufacture of the small amounts of cement used to stabilise the material.

If savings on this scale could be repeated across the whole of the North Popley Development, it would very considerablyreduce the environmental impact of the construction.

Cold recycled bitumen bound material in road pavement

As a further sustainability measure, the asphalt pavement for the access roads was constructed using 250 mm of coldrecycled bitumen bound material with foamed bitumen (Foamix®) placed in two layers. The material was placed as thebase followed by a 55mm binder course of DBM 50 and a 45mm conventional hot asphalt surface course. After laying theFoamix®, the individual layers (150mm maximum layer thickness) were tested for stiffness using the German dynamicplate method after one hour and at 24 hours to ensure the correct stiffness had developed. The air void space was alsomeasured by nuclear density gauge to ensure the minimum 93% had been achieved. Actual values averaged around 97%,which were ideal. The top of the Foamix® course was sprayed with K170 bitumen emulsion to help seal the layer. Theworks were carried out in June 2005. The contractor for the pavement layers was Bardon Aggregates, and the Foamix®was supplied by Foster Yeoman from their depot at Micheldever. Some 300 m3 of Foamix® were laid during constructionof the access roads.

Foamix® is a cold recycled bitumen bound material with foamed bitumen as the main binder. It results in considerableenergy savings compared to conventional hot asphalt. It is commonly used with recycled materials, such as recycledasphalt planings, as the coarse aggregate, thus giving double benefits in sustainability terms. The use of Foamix® has beenhighlighted in other case studies in this series, including footway works on the B3047 at Martyr Worthy and the accessroad to Bar End Household Waste Recycling Centre. The recycled asphalt for North Popley came from arisings frommaintenance works on the A325 at Alice Holt, where the use of recycled aggregates to repair a weak clay embankment washighlighted in another case study in this series.

A contract specific new clause for the Specification for Highway Works was produced by HCC to cover the productionand use of Foamix®. This is based on the latest research and standards relating to cold recycled pavement materials, inparticular TRL Report TRL611: ‘A guide to the use and specification of cold recycled materials for the maintenance ofroad pavements’. HCC had been a partner in the research project that led to the production of TRL611, and were keen toimplement the findings as soon as possible. TRL611 extends the range and application of cold recycled materials in roadpavements beyond what was previously allowed and includes a design guide and specification. These will be incorporatedinto the Specification for Highway Works in due course, but HCC was anxious to utilise them immediately and produced acontract specific clause for this project.

Plate 2 Close up of cement-stabilised chalk

Appendix B – 30

Plate 4 Close up of Foamix®

Plate 3 Second layer of Foamix® being laid on top of first layer

Appendix B – 31

Footways

The sub base for the footways will comprise of cement stabilised chalk or road planings gathered from another part of thedevelopment where an existing road is being removed. The surface course will comprise a 50mm hot base course and a25mm surface course. Again, this practice demonstrates reuse of material on site and prevents extensive lorry movements.Any surplus planings will be sent to Micheldever, to be incorporated into Foamix®.

Conclusions

The Contract 1 works for the North Popley Development at Basingstoke illustrate how the sustainability approach adoptedby HCC can be worked out in practice in a new development. By realising the possibilities for more sustainable solutions,1,000 m3 of chalk were diverted from landfill and retained for productive use on site. Stabilisation with 2% cement enabledthe material to be used as sub-base for the access road and footway. When the material above sub-base level was found tobe better than expected it was retained on site and used as general fill instead of being sent to landfill and replaced withimported primary aggregates. Diversion from landfill of a further 300 m3 of asphalt planings, arising from highwaymaintenance works elsewhere in Hampshire, was enabled by using the materials as coarse aggregate in cold recycledbitumen bound material with foamed bitumen. This process also enabled considerable energy savings to be madecompared to conventional hot asphalt techniques.

There is potential for these savings to be repeated on a much larger scale over the rest of the North Popley Developmentas a result of these successful measures in the Contract 1 works.

Contact details

ClientHampshire County Council – Estate PracticesThe CastleWinchesterHampshireSO23 8UD

DesignerHampshire County Council – Engineering ConsultancyContact: Chris PeakeThe CastleWinchesterHampshireSO23 8UD

Tel.: 01962 847730Email: chris.peake@hants.gov.uk

Main contractorMildren Construction LimitedContact: Brian Pearce, Contracts Manager120 Matchams LaneHurnChristchurchDorsetBH23 6AN

Tel.: 01202 487480

Stabilisation contractorEnvirosoilContact: Richard Martin, Contracts ManagerGround Improvement and Remediation Specialists32 Bernard StreetSouthamptonHampshireSO14 3AY

Tel.: 023 8023 5964

Appendix B – 32

Asphalt contractorBardon AggregatesAggregate Industries UK LtdBardon HillCoalville, LeicestershireLE67 1TL

Tel: 01530 510066

Cold recycled bitumen bound material supplierFoster Yeoman LimitedContact: John BullockMarston HouseMarston BigotFromeSomerset, BA11 5DU

Tel 01373 451001