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SustainableSustainableSustainable Sustainable DurableDurableArchitecturalArchitecturalEcocem Green Cement
Learning Outcomes
The learning outcomes from the presentation are:g p
Understand what GGBS cement is
Understand the environmental technical and architectural reasons whyUnderstand the environmental, technical and architectural reasons why you would specify GGBS cement
Know how to specify GGBS cement
Know the % of GGBS cement to specify for different results/applications
Understand the impact of specifying different % of GGBS cementUnderstand the impact of specifying different % of GGBS cement
History of GGBS
1862: Hydraulic potential of GGBS discovered in GermanyGGBS discovered in Germany
Early 1900’s - Portland Blast Furnace Cements had an established place in the concrete market
2004: More than 5,000,0002004: More than 5,000,000 tonnes of GGBS produced in Germany
2006: Approximately2006: Approximately 2,000,000 tonnes of GGBS produced in UK
2008: Over 400,000 tonnes available in Ireland
About Ecocem Ireland
Long term agreement with partner companies f l i hi hfor supplying high quality GBS
Can supply the Irish pp ymarket with over350,000 tonnes from Dublin
Provide technical back up to specifiers and concrete manufactures
GGBS Manufacture
Steel Manufacture Water to make GBS
GBSGrind to make GGBS
Store GGBS for distribution
GGBS Manufacture
GGBS cement, and OPC
Ecocem Cement in Use
NRA OPW B d Gái ESB C ill RPA B d N M L l A h i iNRA, OPW, Bord Gáis, ESB, Coillte, RPA, Bord Na Mona, Local Authorities
Engineers, Architects, Developers, Precast, House builders, Farmers
EnvironmentalEnvironmentalffAdvantages of using GGBSAdvantages of using GGBS
GGBS and the Environment
CO2 emissions for Ecocem GGBS and cement production
Typical CO2 Emissions for Portland Cement and Ecocem GGBS Productionyp 2(Figures in kg per tonne of output)
1000
600
700
800
900
Other Energy Used
Fossil Fuel Use
pu
t
300
400
500
600Process Emissions
Ton
ne
of O
utp
0
100
200
CEM I CEM II/A GGBS ( ith t ff t )
kg p
er
CEM I CEM II/A GGBS (without offsets)
GGBS and the Environment
CO2 emissions for Ecocem GGBS and cement production
Typical CO2 Emissions for Portland Cement and Ecocem GGBS Productionyp 2(Figures in kg per tonne of output)
1000
600
700
800
900
Other Energy Used
Fossil Fuel Use
pu
t
300
400
500
600Process Emissions
Ton
ne
of O
utp
0
100
200
CEM I CEM II/A E GGBS ( ith t
kg p
er
CEM I CEM II/A Ecocem GGBS (without offsets)
GGBS and the Environment
CO2 emissions for Ecocem GGBS and cement production
Typical CO2 Emissions for Portland Cement and Ecocem GGBS Productionyp 2(Figures in kg per tonne of output)
1000
600
700
800
900
Other Energy Used
Fossil Fuel Use
pu
t
300
400
500
600Process Emissions
Ton
ne
of O
utp
0
100
200
CEM I CEM II/A E GGBS ( ith
kg p
er
CEM I CEM II/A Ecocem GGBS (with offsets)
GGBS and the Environment
Depletion of naturalDepletion of natural resources
For every tonne of Portland cement produced, 1.6 tonnes of limestone/shale are removed from the landscape
GGBS production involves no quarrying of limestone or clay
GGBS and the EnvironmentE i l
What is the impact of
Environmental savings example
replacing 50% of cement with GGBS in an average size shopping centre, using 5 000m3 of concrete?5,000m of concrete?
See calculator on: www.ecocem.ie
Case Study: Case Study: 33--bed bed semi detachedsemi detachedsemi detached semi detached househouse
Reduction in Embodied CO2 through the use of GGBS
3 bed Semi Detached House3 bed Semi Detached House
OriginalOriginal Embodied CO2(38.7 tonnes)
Reduced E b di d COEmbodied CO2(28.4 tonnes)
Larger embodied CO2 reductions are possible with increased replacement
ref: “Embodied CO2 of housing construction in Ireland” - Architecture Ireland – Jan/Feb 2010
Larger embodied CO2 reductions are possible with increased replacement rates of GGBS
GGBS and the Environment
Longer service life from GGBS concreteTime to replacement extendedTime to replacement extended
Specified by NRA on road bridges and structural concrete - 120 year design life achieved
Reduced demand on natural resources for new concrete
Exposure to chloride attack:
Lighter colour - The Albedo Benefit
Solar radiation i fl t d b This heat cannotis reflected by lighter coloured surfaces
This heat cannot pass out of the earth’s atmosphere through the greenhouse gas layer
Darker coloured surfaces absorb solar radiation
Every 100m2 of GGBS concrete pavement in
Ireland will offsetand re emit it as heat
Ireland will offset 6 tonnes of CO2/annum
Lighter colour - The Heat Island Benefit
Reduce heat island effect
Reduces air conditioning requirement; cost and environmental benefit studies have shown reductions of more than 20% inbenefit – studies have shown reductions of more than 20% in building cooling costs whose albedo has been increased (in the US potential saving of $1 billion per year)
Health benefit
Lighter colour – Reflectance Benefit
Reduces outdoor lighting requirements by enhancing night time visibility
Saving money, energy and carbon emissions
Approx. 30% less lighting needed to achieve sameApprox. 30% less lighting needed to achieve same visibility for concrete as it does for asphalt
Properties &Properties &Properties &Properties &Advantages of using GGBSAdvantages of using GGBS
GGBS Chemical Composition
Same constituents as OPC
Different proportions• Less CaO• More Si02
• More Al2O3
Mix design using GGBS cement
GGBS cement replaces ordinary Portland cement on a one-for-one basisone for one basis
No change in any other element of the mix design: • sand• sand• aggregates• w/c ratio (can be reduced)• Admixtures
Concrete manufacture• Batch duration is the same• Time to transport - may be appropriate to extend it
GGBS in Concrete
Engineering benefits start at 30%
Usage varies from 30 up to 85%
Most often specified at 50%Most often specified at 50%• Treated same as Portland cement concrete
No adjustment striking timesPlacing, compacting and powerfloatingConcrete admixtures compatible.
Working with GGBS Concrete
Placing, compacting and pumping easier:eas e• lower relative density• smaller particle sizes
Powerfloating as normal
Setting times longer by 0.5 – 2 hrs g g y
Slower rate of bleeding
W t d d 3% t 5% lWater demand 3% to 5% lower
Compatible with admixtures
Strength – cement prisms
80.0
60.0
70.0
40.0
50.0
mm
2
20 0
30.0
N/m
0 0
10.0
20.0
Days0.0
7 28 90
100/0 Sept 50/50 Sept 30/70 Sept100%OPC/0%GGBS 50%OPC/50%GGBS 30%OPC/70%GGBS
Strength – early age development
on a 350mm
Strength – temperature effects
1.1 metres in depth
40
45
50Foundation Slab: C40/50 @ 70% GGBS
25
30
35
40
h N
/mm
2
10
15
20
Stre
ngt
h
0
5
1 2 3 4
Standard TMCDay Age
Standard TMC
Strength – long term development
95
75
85
95
45
55
65
N/m
m2
42.5 & 50% GGBS
25
35
45
42.5
150 50 100 150 200
Days
Strength – long term development
45
C30/37 concrete, Greystones Marina 50% GGBS: 50% CEM II
Core Strength vs time
40
Core Strength vs time
35
engt
hM
pa
30
Stre
25
1 month 6 Months 12 months 18 Months1 month 6 Months 12 months 18 Months
Durability of GGBS Concrete - Chlorides
Chloride Penetration
L hl id i diff i itLower chloride ion diffusivity
Lower porosity/permeability
Applications: roads and bridges, car parks, sea defences, marine structures.
Durability of GGBS Concrete - Chlorides
Effect of GGBS on chloride diffusion in concrete
14
16
/s
CEM II/A-L 320 kg/m3
CEM II/A-V 320 kg/m3
8
10
12
icie
nt
10-1
2m
2/
CEM II/A-L 400 kg/m3
CEM II/A-V 400 kg/m3
4
6
8
iffu
sio
n c
oe
ffi
0
2
0% GGBS 50% GGBS 70% GGBS
Di
0% GGBS 50% GGBS 70% GGBS
Durability of GGBS Concrete - Chlorides
Durability of GGBS Concrete - Chlorides
BS 6349 – Maritime Structures – Table 22
Durability of GGBS Concrete - Sulphates
Sulphate Resistance
Sulphates react with C3A and Ca(OH)2 to formSulphates react with C3A and Ca(OH)2 to form ettringite
Sulphate Resisting cement (SRPC) has reduced C3A, but no reduced Ca(OH)2, and no reduced porosityporosity
SRPC cannot be used in marine environments
GGBS much lower price than SRPC
Note: In BS8500 the only option recommended as suitable for the most severe
l h (Cl Csulphate exposure (Class DC-4m) is concrete containing at least 66% GGBS
Use of Sulphate resistantUse of Sulphate resistant cement is not permitted
Durability of GGBS Concrete - Sulphates
Aggressors:
S l h tSulphatesSodium Sulphate Na2SO4Magnesium Sulphate MgSO4
AcidsAcidsSulphuric Acid H2SO4
0.5Durability of GGBS Concrete - SulphatesMasters Study in UCD, Dublin
0.4
0.45
UCD, Dublin
0.3
0.35
sio
n
0.2
0.25
Ex
pa
ns
CEM I
CEMII
SRPC
CEM I + 70% GGBS
0 1
0.15
%
CEM II + 50% GGBS
CEM II + 70% GGBS
0.05
0.1
0
Days Exposure
Durability of GGBS Concrete - SulphatesBRE Digest 1
Sulphate resistance
Durability of GGBS Concrete - Sulphates
Durability of GGBS Concrete
0% GGBS0% GGBS
30% GGBS
50% GGBS
Heat of Hydration
GGBS lowers peak and overall heat
Reduces thermal stressingReduces thermal stressing
Reduces micro-cracking (particularly useful in water retaining structures, basements, podium slab, bridges, stadiums, secant pile walls etc )pile walls etc.)
Optimum substitution level 60 – 85%
Heat of Hydration - wind farm bases
Images courtesy of Wind Farm Civils
Heat of hydration - controlling thermal cracking
temperature differential – 1 metre deep slab summer Basement slab with 70% GGBS
45
50
Min Max Difference
25
30
35
40
10
15
20
25
0
5
08:15 13:00 17:30 08:15 13:00 17:30 08:15 13:00 17:30 08:15 13:00 17:30 08:15 13:00 17:30 08:15 13:00 17:30 08:15 13:00 17:30 08:15 13:00 17:30
06/09/2007 07/09/2007 08/09/2007 09/09/2007 10/09/2007 11/09/2007 12/09/2007 13/09/2007/ / / / / / / / / / / / / / / /
Heat of hydration - controlling thermal cracking
temperature differential – 2.5 metre deep slabBasement slab with 70% GGBS
60.0
70.0 Top
Core
Bottom
Differential Top to Core
Diff ti l B tt t C
40.0
50.0
Differential Bottom to Core
30.0
empe
ratu
re (o C
)
10.0
20.0
Te
0.00 21 28 33 46 58 70 77 92 99 118 139 164 189 234
Time after placing (hours)
Heat of hydration - controlling thermal cracking
Convention Centre, Dublin - basement
Resistance to Fire
Architectural Qualities and Appearance
GGBS is an off-white powderGGBS cement, and OPCLighter, more even-coloured concrete
Smoother, more defect-free ,surface
Suppresses/Eliminates efflorescenceefflorescence
Lower pigment requirements –20% saving
GGBS b d ti lGGBS can be used as partial replacement for white cement, up to 70%
Architectural Qualities and Appearance
Bridge pier and bridge deckbridge deck, Enfield bypass
Bridge deck 100% OPCBridge deck 100% OPCBridge pier 50% GGBS
Architectural Qualities and Appearance
Cork Civic Offices - 50% GGBS
Architectural Qualities and Appearance
Cathleen Falls Bridge – 50% GGBS2006 ICS, Design and Construction Awards
Architectural Qualities and Appearance
Sleeping Giant – 70% GGBS2007 ICS, Design and C t ti A dConstruction Award
Architectural Qualities and Appearance
2008 ICS
Sean O’Casey Building Dublin – 50% GGBS
2008 ICS, Design and Construction
Award
Architectural Qualities and Appearance
Aviva StadiumStadium Dublin
40-70% GGBS
Architectural Qualities and Appearance
Father Collins Park, Dublin70% GGBS
Architectural Qualities and Appearance
Charlestown Retail Centre – 45% GGBS
Architectural Qualities and Appearance
2009 ICS Design and
Cable Stay Bridge, Waterford – 50% GGBS
2009 ICS, Design and Construction Awards
Architectural Qualities and Appearance
Mizen Head Bridge – 50% GGBS- replacing first RC bridge constructed in Ireland in 1909
Image courtesy of RPS
Ecocem in Concrete = Low Carbon Concrete
Carbon Neutral Concrete
The world’s first Carbon Neutral Building Material launched in 2007 in partnership with the biggest
i th I i h C t ti I d tnames in the Irish Construction Industry:
Treasury Holdings
Pierse
Durkan Group
McNamara
JJ RhatiganJJ Rhatigan
Details on all prestigious projects can be found on
www carbonneutralconcrete iewww.carbonneutralconcrete.ie
How to specify GGBS
COARSE & FINE AGGREGATES Coarse and fine aggregates shall comply with I.S. EN 12620.
CHLORIDE CONTENT The total chloride content of the concrete mix for reinforced concrete shall not exceed 0.4% expressed as a percentage of chloride ion by weight of cement.
CEMENT Normal Portland cement (CEM I, CEM II/A) shall comply with the requirements of IS EN 197 1 The cement shall be delivered to site in standard bags or in bulk containers and shallEN 197-1. The cement shall be delivered to site in standard bags or in bulk containers and shall be stored under dry conditions.
CEMENT ADDITIONS Ground Granulated Blastfurnace Slag (GGBS) is permitted in I.S. EN 206-1 to be used as a Type II addition to CEM I or CEM II/A cements in concrete. Where GGBS is added it replaces the CEM I or CEM II/A cement on a one-for-one basis; the total cementitous material content of the concrete mix does not change, and the GGBS counts fully towards the total cement content and water/cement ratio in concrete. GGBS shall comply I.S. EN 15167-1 and be ground to a blaine of > 4000 cm2/g.
A cement combination comprising 50% GGBS and 50% CEM I or CEM II/A is to be used in all concrete throughout the Project, unless otherwise specified on the drawings or by the Engineer.
Multiple Benefits
Best durability (longer life)• Factor of safety• Reduce lifetime maintenance cost
Best sustainable materialBest sustainable material• Reduces CO2 emissions• Demonstrates commitment to a sustainable agenda
P iti CSR• Positive CSR
Best Architectural• Whiter brighter concrete• Whiter, brighter concrete
Best value for money
Thank You
Thank you for your attentiony y
Should you have any questions in the future:y y q
David O’Flynn; 087 965 4891d fl [email protected]