Chalmers University of Technology 1
Environmental benefits by using construction methods with geosynthetics Prof. Dr.-Ing. Holger Wallbaum Professor in Sustainable building [email protected]
Berlin September 24, 2014
Chalmers University of Technology 2
Content
• Introduction to Life Cycle Assessment • Goal & Scope • Case 1: Filter layer • Case 2: Road Foundation • Case 3: Landfill Construction • Case 4: Slope Retention • Overall conclusions and outlook
Chalmers University of Technology 3
Material needed per capita per year 50 tons =
0 2 2 4 4 6 6 8 10 tons per capita
100 % mineral raw materials
fossil fuels
residence
food
clothing
health
education
leisure
community
others
6
11
13
5
9
6
20
29
biological raw materials
the visible material load the hidden material “rucksack”
unconverted materials
earth displacement
erosion
Our «ecological rucksack»
Chalmers University of Technology 4
GDP Jobs Energy / CO2
Raw materials Land harvesting
7% 10%
50%
30-40%
60%
Worldwide importance of the construction industry
Fresh water
17%
Chalmers University of Technology 5
Sustainable development strategies
Source: UNEP Resource panel, Findings report: 16, 2012
Chalmers University of Technology 6
European Developments • Waste Framework Directive (2008) • Energy Performance of Buildings Directive (2010) • Thematic Strategy for Urban Environment (2006) • Flagship Initiative „Resource Saving Europe“ (2011) • Roadmap for a „Resource Saving Europe“ (2011) • Lead Market Initiative „Sustainable Construction“ (2007) • Action Plan „Sustainable Construction“ • CEN/TC 350 Sustainability of Construction Works • Construction Products Regulation (2011 ... 2013) with Basic Requirement
No. 7
Chalmers University of Technology 7
Life Cycle Assessment Tool to calculate the environmental impact of products or services
ISO 14040
Goal and Scope
Definition
Inventory analysis
Impact assessment
Interpretation
Direct applications: •Product development and improvement •Strategic planning •Public policy making •Marketing •Benchmarking •Ecolabels and product declarations
Life Cycle Assessment Framework
Chalmers University of Technology 8
Reasons for carrying out a LCA
• Explore and learn about the life cycle • Support product development and strategic planning • Marketing This can be done by • Comparison of two (or more) products, processes or
services • Improvement of one product (hot spot analysis)
Chalmers University of Technology 9
Purpose for carrying out a LCA
• Improvement possibilities? • Activities with largest contribution? • Environmental consequences of changes? • Environmental consequences of using
secondary recycled raw material? • Environmentally preferable choice of products
used in a specific application?
Chalmers University of Technology 10
The life cycle of resource extraction and use
Source: UNEP Resource panel, Findings report: 17, 2012
Chalmers University of Technology 11
Input (resources): - crude oil - bauxite - land - …
Output (emissions): atmosphere - CO2 - NOX - noise - particulates water - glycol - mineral oil - tributyl tin
Manifold environmental impacts
Chalmers University of Technology 12
Assessing environmental impacts Emission Effect Damages
For example: Climate change
Chalmers University of Technology 14
Content
• Introduction to Life Cycle Assessment • Goal & Scope • Case 1: Filter layer • Case 2: Road Foundation • Case 3: Landfill Construction • Case 4: Slope Retention • Overall conclusions and outlook
Chalmers University of Technology 15
Goal and Scope of the Study
The goal definition shall unambiguously state the intended application, the reason for carrying out the study and the intended
audience (ISO 14040)
Chalmers University of Technology 16
Goal of the study Environmental assessment of commonly applied construction versus
geosynthetic materials
Description Alternatives Case Filter layer gravel based filter 1A geosynthetics based filter 1B Road foundation conventional road (no stabilisation needed) 2A geosynthetics based foundation 2B cement/lime based foundation 2C Landfill construction gravel based drainage layer 3A geosynthetics based drainage layer 3B Slope retention reinforced concrete wall 4A geosynthetics reinforced wall 4B
Chalmers University of Technology 17
Goal of the project
• assess the environmental performance of geosynthetics and competing building materials
to be able to:
• continuously improve the performance of geosynthetics production
• formulate requirements on suppliers
• communicate environmental information to customers, clients and stakeholders
Chalmers University of Technology 18
Scope of the project: four cases
• Filter layer: Application of geosynthetics vs. classical filter material
• Road foundation: conventional road vs. geosynthetics vs. cement/lime stabilisation
• Landfill construction: Application of drainage gravel vs. drainage mat
• Slope retention: Reinforced concrete retaining wall vs. geosynthetics reinforced with soil
Chalmers University of Technology 19
Environmental impact categories
Indicators Considered impacts (substances)Acidification acidfiying substances (NOX, NH3, SO2)
Eutrophication emissions into water and air (P, N, org Substances)Global Warming Potential all substances contributing to climate changePhotochemical Oxidation summer smog (SO2, CO, Methane, Pentane, Butane, etc)
CED non-renewable fossil and nuclear energy carriersCED renewable hydro, solar, wind, geothermal, biomassParticulate matter primary and secondary particulates (PM10, NOX, NH3, SO2)
Land competition land occupationWater use total amount of water used, excluding turbined water
The calculations are performed with the software SimaPro (PRé Consultants 2012).
Chalmers University of Technology 20
Data collection
• Questionnaires completed by EAGM member companies with information about: - production volumes and size of site(s) - energy and water consumption, - raw material consumption (feedstock), - working material consumption - process related emissions to air and water - wastes generated
Chalmers University of Technology 21
System boundaries
Raw material extraction
Building material production
Background processes (energy supply, transports, basic materials)
Construction
Landfill
Material production Infrastructure element Disposal
Maintenanceand Operation
Recycling
Incineration Energy
Material used in other product
System boundary
Geotextile production(EAGM members)
Raw material extraction
Building material production
Background processes (energy supply, transports, basic materials)
Construction
Landfill
Material production Infrastructure element Disposal
Maintenanceand Operation
Recycling
Incineration Energy
Material used in other product
System boundary
Geotextile production(EAGM members)
Chalmers University of Technology 22
Uncertainty analysis: Monte Carlo-Simulation
Input data:
Results:
Max (97.5%)
Min (2.5%) 0
10
20
30
40
50
60
NO
x, h
igh
pop.
[mg/
MJ h
eat]
Emissions boiler Fuel supply chain
cumulative NOx-emissions
Monte-Carlo- simulation
Credits: PSI
direct NOX-emissions
Chalmers University of Technology 23
Content
• Introduction to Life Cycle Assessment • Goal & Scope • Case 1: Filter layer • Case 2: Road Foundation • Case 3: Landfill Construction • Case 4: Slope Retention • Overall conclusions and outlook
Chalmers University of Technology 25
Functional unit and system boundaries
• 1 m2 filter with hydraulic conductivity (k-value) of 0.1 mm/s or more, 30 years life time
• manufacture and disposal of - 30 cm gravel layer - geosynthetic layer
• Sensitivity analysis - Specification: 20 cm gravel - Specification: 40 cm gravel
Chalmers University of Technology 26
Data sources • Filter specification: EAGM • Geosynthetics: EAGM members • Building machines: Swiss statistical fuel consumption, Frischknecht 2004,
Breiter 1983 • Background data: ecoinvent data v2.2
(internationally reknown life cycle inventory database)
Chalmers University of Technology 28
Inventory of road construction Unit Case 1A Case 1B Total Total Gravel t/m2 0.69 - Geosynthetic layer m2/m2 - 1 Diesel used in building machines MJ/m2 2.04 1.04 Transport, lorry tkm/m2 34.5 0.035 Transport, freight, rail tkm/m2 - 0.07 Particulates, > 10 µm g/m2 4.8 0 Particulates, > 2.5 µm & < 10 µm g/m2 1.3 0
Chalmers University of Technology 30
Results of sensitivity analysis
1A: standard 1B: standard 1AS1: 40 cm gravel 1AS2: 20 cm gravel
per
m2
filt
er
Chalmers University of Technology 31
Conclusions case 1 • Low share of geosynthetic material
• The use of geosynthetics leads to lower environmental impacts
• Geosynthetic replaces unprocessed material (gravel) → at least a layer of 4.5 cm gravel needs to be saved that the application of geosynthetics leads to lower impacts
• If 1 m2 filter layer of 30 cm gravel is saved (standard case) → savings of 7 kg CO2-eq/km
• Results are significant and reliable with regard to all environmental indicators
Chalmers University of Technology 32
Content
• Introduction to Life Cycle Assessment • Goal & Scope • Case 1: Filter layer • Case 2: Road Foundation • Case 3: Landfill Construction • Case 4: Slope Retention • Overall conclusions and outlook
Chalmers University of Technology 33
Case 2
Road foundation
conventional road vs geosynthetic based foundation vs
cement/lime based foundation
Chalmers University of Technology 34
Functional unit and system boundaries
• 1 m road class III on stabilised foundation with 12 m width, 30 years life time
• manufacture and disposal of - surface layer - binder course - foundation
• operation of the road (lighting etc.) and traffic excluded • additional focus on stabilisation layer
Chalmers University of Technology 35
Sensitivity analysis
• Case 2BS1: replacement of frost-sensitive soil • Case 2BS2: no separation geosynthetic • Case 2CS1: quicklime only • Case 2CS2: cement only
Chalmers University of Technology 37
Inventory of road foundation Unit Case 2A Case 2B Case 2C
Total Thereof
foundation stabiliser
Total Thereof
foundation stabiliser
Total Thereof
foundation stabiliser
Bitumen t/m 0.3 - 0.3 - 0.3 Gravel t/m 33.9 - 24.3 - 18.7 6.9 Cement t/m - - - - 0.16 0.16 Quicklime t/m - - - - 0.26 0.26 Geosynthetic separator layer Geosynthetic stabiliser layer
m2/m m2/m
- -
- -
12 12
12 12
- -
- -
Diesel used in building machines MJ/m 1957 - 1972 - 1969 14.9
Transport, lorry tkm/m 1711 - 1232 - 994 41.4 Transport, freight, rail tkm/m - - 2.0 2.0 41.4 41.4
Land use m2/m 12 12 12 12 12 12 NMVOC kg/m 2.19 - 2.19 - 2.19 - Particulates, > 10 µm
g/m 237 - 170 - 131 -
Particulates, > 2.5 µm & < 10 µm
g/m 63 - 45 - 35 -
Chalmers University of Technology 39
Climate change impact savings • Geosynthetics instead of conventional road:
80 t CO2-eq/km
• Geosynthetics instead of cement/quicklime stabilization: 300 t CO2-eq/km
Chalmers University of Technology 40
Conclusions case 2 • Lower environmental impacts of geosynthetics road foundation
compared to a conventional road
• Mixed results of geosynthetics road foundation compared to cement/lime road foundation → trade off
• Lower impacts of geosynthetics road foundation: climate change, summer smog, renewable energy
• Similar impacts: acidification, particulate matter, non renewable energy
• Higher impacts of geosynthetics road foundation: eutrophication, land competition, water use → at least factor 2 lower environmental impacts of geosynthetics option compared to classical (cement stabilised) option
Chalmers University of Technology 41
Content
• Introduction to Life Cycle Assessment • Goal & Scope • Case 1: Filter layer • Case 2: Road Foundation • Case 3: Landfill Construction • Case 4: Slope Retention • Overall conclusions and outlook
Chalmers University of Technology 42
Case 3
Landfill construction
gravel based drainage vs geosynthetics based drainage
Chalmers University of Technology 43
Functional unit and system boundaries
• 1 m2 surface area of landfill drainage layer • manufacture and disposal of
- filter geosynthetic layer - filter layer (gravel and geosynthetic, respect.) - protection geosynthetic layer
• operation of the landfill excluded • Sensitivity analysis: Euro 5 instead of average lorry
Chalmers University of Technology 45
Inventory of landfill drainage Unit Case 3A Case 3B Gravel t/m2 0.90 - Geosynthetic filter layer Geosynthetic protection layer Geosynthetic drainage core1
m2/m2
m2/m2
m2/m2
1 1 -
- - 1
Diesel used in building machines MJ/m2 4.5 3.8 Transport, lorry tkm/m2 45.1 0.2 Transport, freight, rail tkm/m2 0.1 0.3 Land use m2/m2 1 1 Particulates, > 10 µm g/m 6.3 - Particulates, > 2.5 µm & < 10 µm g/m 1.7 - 1The core consists of the drainage layer, geosynthetic filter and protection layer. The latter two are glued on the drainage layer.
Chalmers University of Technology 46
Results case 3 pe
r m
2 dr
aina
ge la
yer
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%w
ithou
t geo
synt
hetic
(3A
)
with
geo
synt
hetic
(3B
)
with
out g
eosy
nthe
tic (3
A)
with
geo
synt
hetic
(3B
)
with
out g
eosy
nthe
tic (3
A)
with
geo
synt
hetic
(3B
)
with
out g
eosy
nthe
tic (3
A)
with
geo
synt
hetic
(3B
)
with
out g
eosy
nthe
tic (3
A)
with
geo
synt
hetic
(3B
)
with
out g
eosy
nthe
tic (3
A)
with
geo
synt
hetic
(3B
)
with
out g
eosy
nthe
tic (3
A)
with
geo
synt
hetic
(3B
)
with
out g
eosy
nthe
tic (3
A)
with
geo
synt
hetic
(3B
)
with
out g
eosy
nthe
tic (3
A)
with
geo
synt
hetic
(3B
)
Acidification Eutrophication Global warming2007 (GWP100)
Photochemicaloxidation
CED non-renewable
CED renewable Particulatematter
Land competition Water use
Landfill Gravel Geosynthetic Building machine Transport Disposal
Chalmers University of Technology 47
Results of sensitivity analysis
3A: standard 3AS1: Euro 5 lorry 3B: standard 3BS1: Euro 5 lorry
per
m2
drai
nage
laye
r
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
with
out g
eosy
nthe
tic (3
A)
with
out g
eosy
nthe
tic (3
AS
1)w
ith g
eosy
nthe
tic (3
B)
with
geo
synt
hetic
(3B
S1)
with
out g
eosy
nthe
tic (3
A)
with
out g
eosy
nthe
tic (3
AS
1)w
ith g
eosy
nthe
tic (3
B)
with
geo
synt
hetic
(3B
S1)
with
out g
eosy
nthe
tic (3
A)
with
out g
eosy
nthe
tic (3
AS
1)w
ith g
eosy
nthe
tic (3
B)
with
geo
synt
hetic
(3B
S1)
with
out g
eosy
nthe
tic (3
A)
with
out g
eosy
nthe
tic (3
AS
1)w
ith g
eosy
nthe
tic (3
B)
with
geo
synt
hetic
(3B
S1)
with
out g
eosy
nthe
tic (3
A)
with
out g
eosy
nthe
tic (3
AS
1)w
ith g
eosy
nthe
tic (3
B)
with
geo
synt
hetic
(3B
S1)
with
out g
eosy
nthe
tic (3
A)
with
out g
eosy
nthe
tic (3
AS
1)w
ith g
eosy
nthe
tic (3
B)
with
geo
synt
hetic
(3B
S1)
with
out g
eosy
nthe
tic (3
A)
with
out g
eosy
nthe
tic (3
AS
1)w
ith g
eosy
nthe
tic (3
B)
with
geo
synt
hetic
(3B
S1)
with
out g
eosy
nthe
tic (3
A)
with
out g
eosy
nthe
tic (3
AS
1)w
ith g
eosy
nthe
tic (3
B)
with
geo
synt
hetic
(3B
S1)
with
out g
eosy
nthe
tic (3
A)
with
out g
eosy
nthe
tic (3
AS
1)w
ith g
eosy
nthe
tic (3
B)
with
geo
synt
hetic
(3B
S1)
Acidification Eutrophication Global warming2007 (GWP100)
Photochemicaloxidation
CED non-renewable
CED renewable Particulatematter
Land competition Water use
Landfill Gravel Geosynthetic Building machine Transport Disposal
Chalmers University of Technology 48
Conclusions case 3
• The use of geosynthetics leads to lower environmental impacts concerning all indicators investigated, except land competition
• If geosynthetics are applied → savings of 220 t CO2-eq for a typical landfill site (30‘000 m2)
• Results are fully reliable for all indicators except land competition
Chalmers University of Technology 49
Content
• Introduction to Life Cycle Assessment • Goal & Scope • Case 1: Filter layer • Case 2: Road Foundation • Case 3: Landfill Construction • Case 4: Slope Retention • Overall conclusions and outlook
Chalmers University of Technology 50
Case 4
Slope Retention
Reinforced concrete retaining wall vs geosynthetic reinforced with soil
Chalmers University of Technology 51
Functional unit and system boundaries
• 1 m of a 3 m high slope retention • manufacture and disposal of supporting structure • operation of the slope retention excluded • Sensitivity analysis: Euro 5 instead of average lorry
Chalmers University of Technology 53
Inventory of slope retention Unit Case 4A Case 4B Concrete, sole plate and foundation m3/m 1.60 - Lean mix concrete m3/m 0.24 - Structural concrete m3/m 2.10 0.31 Reinforcing steel kg/m 153 - Gravel t/m 4.3 4.3 Bitumen kg/m 2.84 - Three layered laminated board m3/m 0.01 - Geosynthetic m2/m - 39.2 Polystyrene foam slab kg/m 0.25 - Polyethylene kg/m 1.74 2.02 Diesel in building machine MJ/m 11.6 53.9 Transport, lorry tkm/m 701 265 Transport, freight, rail tkm/m 33.2 6.9 Land use m2/m 1.0 0.6 NMVOC g/m 20 -
Chalmers University of Technology 54
Results case 4 pe
r m
slo
pe r
eten
tion
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
with
out g
eosy
nthe
tic(4
A)
with
geo
synt
hetic
(4B
)
with
out g
eosy
nthe
tic(4
A)
with
geo
synt
hetic
(4B
)
with
out g
eosy
nthe
tic(4
A)
with
geo
synt
hetic
(4B
)
with
out g
eosy
nthe
tic(4
A)
with
geo
synt
hetic
(4B
)
with
out g
eosy
nthe
tic(4
A)
with
geo
synt
hetic
(4B
)
with
out g
eosy
nthe
tic(4
A)
with
geo
synt
hetic
(4B
)
with
out g
eosy
nthe
tic(4
A)
with
geo
synt
hetic
(4B
)
with
out g
eosy
nthe
tic(4
A)
with
geo
synt
hetic
(4B
)
with
out g
eosy
nthe
tic(4
A)
with
out g
eosy
nthe
tic(4
B)
Acidification Eutrophication Global warming2007 (GWP100)
Photochemicaloxidation
CED non-renewable CED renewable Particulate matter Land competition Water use
Slope retention Concrete Gravel Geosynthetic Reinforcing steel Bitumen Wooden board Plastic Building machine Transport Disposal
Chalmers University of Technology 55
Results of sensitivity analysis
4A: standard 4AS1: Euro 5 lorry 4B: standard 4BS1: Euro 5 lorry
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
with
out g
eosy
nthe
tic (4
A)
with
out g
eosy
nthe
tic (4
AS
1)
with
geo
synt
hetic
(4B
)
with
geo
synt
hetic
(4B
S1)
with
out g
eosy
nthe
tic (4
A)
with
out g
eosy
nthe
tic (4
AS
1)
with
geo
synt
hetic
(4B
)
with
geo
synt
hetic
(4B
S1)
with
out g
eosy
nthe
tic (4
A)
with
out g
eosy
nthe
tic (4
AS
1)
with
geo
synt
hetic
(4B
)
with
geo
synt
hetic
(4B
S1)
with
out g
eosy
nthe
tic (4
A)
with
out g
eosy
nthe
tic (4
AS
1)
with
geo
synt
hetic
(4B
)
with
geo
synt
hetic
(4B
S1)
with
out g
eosy
nthe
tic (4
A)
with
out g
eosy
nthe
tic (4
AS
1)
with
geo
synt
hetic
(4B
)
with
geo
synt
hetic
(4B
S1)
with
out g
eosy
nthe
tic (4
A)
with
out g
eosy
nthe
tic (4
AS
1)
with
geo
synt
hetic
(4B
)
with
geo
synt
hetic
(4B
S1)
with
out g
eosy
nthe
tic (4
A)
with
out g
eosy
nthe
tic (4
AS
1)
with
geo
synt
hetic
(4B
)
with
geo
synt
hetic
(4B
S1)
with
out g
eosy
nthe
tic (4
A)
with
out g
eosy
nthe
tic (4
AS
1)
with
geo
synt
hetic
(4B
)
with
geo
synt
hetic
(4B
S1)
with
out g
eosy
nthe
tic (4
A)
with
out g
eosy
nthe
tic (4
AS
1)
with
out g
eosy
nthe
tic (4
B)
with
out g
eosy
nthe
tic (4
BS
1)
Acidification Eutrophication Global warming2007 (GWP100)
Photochemicaloxidation
CED non-renewable CED renewable Particulate matter Land competition Water use
Slope retention Concrete Gravel Geosynthetic Reinforcing steel Bitumen Wooden board Plastic Building machine Transport Disposal
per
m s
lope
ret
enti
on
Chalmers University of Technology 56
Conclusions case 4
• Relatively high share of geosynthetics in the total environmental impacts of the system
• The use of geosynthetics leads to lower environmental impacts concerning all indicators investigated
• If geosynthetics are applied → savings of 1 t CO2-eq/m
• Results are fully reliable for all indicators
Chalmers University of Technology 57
Critical Review • Panel of three external, independent Experts:
- Hans-Jürgen Garvens (Chair), Germany - Maartje Sevenster, Isaacs, Australia - Lars-Gunnar Lindfors, IVL, Stockholm, Sweden
RESULTS • Study performed in full accordance with ISO 14040 & 14044 • Using geosynthetics can have advantages but is not always
preferable • Study gives a sufficient information base to decide on the
system to use with regard to environmental issues • Comprehensive and broad view on sample construction
systems using geosynthetics
Chalmers University of Technology 58
Content
• Introduction to Life Cycle Assessment • Goal & Scope • Case 1: Filter layer • Case 2: Road Foundation • Case 3: Landfill Construction • Case 4: Slope Retention • Overall conclusions and outlook
Chalmers University of Technology 59
Conclusions Geosynthetics
• Highest share on impacts caused by raw materials (mainly plastic) • National electricity mixes influence the results • Rather small influence of infrastructure, disposal, working materials,
transports and thermal energy consumption
Chalmers University of Technology 60
Overall conclusions • Geosynthetic layers cause lower climate change impacts in all cases
considered
• The use of geosynthetic layers may also lead to lower other environmental impacts except in case 2
• Case 2: - trade off between climate change and eutrophication (among others) - cement stabilised foundation with lower non renewable energy demand
• The variation in environmental impacts of geosynthetics manufacture does not affect the overall results
• Despite the necessary simplifications and assumptions, the results of the comparison are considered to be significant and reliable
• Establish key parameter models to model case studies
Chalmers University of Technology 61
Background report “Comparative Life Cycle Assessment of Geosynthetics versus Conventional Construction Materials” on behalf of the and further conference and journal paper is available on:
http://www.eagm.eu/lca-study/
Chalmers University of Technology 62
Construction Products Regulation
New Basic Requirement No. 7: „Sustainable Use of Natural Resources“ The construction works must be designed, built and demolished in such a way that the use of natural resources is sustainable and ensures the following:
a. recyclability of the construction works, their materials and parts after demolition
b. durability of the construction works c. use of environmentally compatible raw and secondary material in the d. construction
➝ all product standards have to be revised!
Chalmers University of Technology 63
Awarding construction contracts in Germany
§6 of the award regulation (VgV), amended in 2003, last amended on 12.7.12: ( 3) The terms of reference should be made with regard to energy efficiency, especially following requirements :
1 the highest level of performance and energy efficiency 2 where available, the highest energy efficiency class in terms of energy consumption labelling.
( 4) The terms of reference or at another suitable location in the tender documents are to call for the following information from the bidders :
1 concrete information on energy consumption, unless the goods offered on the market, technical devices or equipment differ in the allowable energy consumption only slightly, and 2 in appropriate cases, 1 a) a minimized life cycle cost analysis or 2 b ) the results of a point a comparable method for checking the efficiency.
(5) The authority referred to in paragraph 4 may check submitted information and to request further additional explanations of the bidders. (6 ) In determining the most economical offer according to § 97 paragraph 5 of the Act against Restraints of Competition is to consider the basis of the information referred to in paragraph 4 or the results of a review under paragraph 5 to be determined appropriate energy efficiency as an award criterion.