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The Uses of GGBS in Concrete
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October 2009October 2009Ecocem Ireland LtdEcocem Ireland Ltd
1862: Hydraulic potential of GGBS discovered in GermanyEarly 1900’s - Portland Blast Furnace Cements had an established place in the concrete market
2004: More than 5,000,000 tonnes of GGBS produced in Germany2006: Approximately 2,000,000 tonnes of GGBS produced in UK
2008: Over 400,000 tonnes available in Ireland2008: Over 400,000 tonnes available in Ireland
Long term agreement with partner companies for supplying high quality GBSCan supply the Irish market with over 350,000 tonnes from Dublin
Provide technical back up to specifiers and concrete manufactures
Steel Manufacture Water to make GBS
GBSGrind to make GGBS
Store GGBS for distribution
GGBS cement, and OPC
NRA, OPW, Bord Gáis, ESB, Coillte, RPA, Bord Na Mona, Local Authorities, O , o d Gá s, S , Co te, , o d a o a, oca ut o t es
Engineers, Architects, Developers, Precast, House builders, Farmers
EnvironmentalEnvironmentalEnvironmentalEnvironmentalAdvantages of using GGBSAdvantages of using GGBS
Conflict in Darfur isConflict in Darfur is directly linked to Climate Change
A rise of 1 metre in ocean levels will displace 35 Million
l ipeople in Bangladesh.
Cement manufacture: Second largest source of industrial CO2
Releases harmful pollutants
Significant energy user
D l t t lDepletes natural resources
CO2 emissions for Ecocem GGBS and cement production
Typical CO2 Emissions for Portland Cement and Ecocem GGBS Production(Figures in kg per tonne of output)
700800900 Generation of Electricity Used
Fossil Fuel Useutpu
t
400500600700
Process Emissions
Tonn
e of
O
0100200300
kg p
er T
0
Portland Cement Ecocem GGBS
Depletion of natural presourcesFor every tonne of Portland
t d d 1 6 t fcement produced, 1.6 tonnes of limestone/shale are removed from the landscape
GGBS production involves no quarrying of limestone or clay
Environmental savingsEnvironmental savings example
What is the impact of replacing 50% of cement with GGBS in an
average size shopping centreaverage size shopping centre, using 5,000m3 of concrete?
See calculator on:
www.lowcarbonconcrete.ie
Longer service life from GGBS concrete
Time to replacement extendedSpecified by NRA on road bridges and structural concretep y gReduced demand on natural resources for new concrete
Exposure to chloride attack:Exposure to chloride attack:
Albedo Effect – measure of solar reflectivityFor every 15-25m2 of Ecocem concrete surface theyincreased solar reflectivity will save 1 tonne of CO2 everyyearA 100 150 2 d i t h th COA 100-150m2 driveway to a house can save the same CO2as will be produced by 2 cars
Drive carbon free for life
EU procurement Rules Directive 2004/18/EC
Recital 5 states that "contracting authorities may contribute to the protection of the environment and the promotion of sustainable development"
Recital 6 states “Nothing in this Directive should prevent the imposition or enforcement of measures necessary to protect public policy, public morality, public security health human and animal life or the preservation of plant life in particularsecurity, health, human and animal life or the preservation of plant life, in particular with a view to sustainable development…”
Article 26 states ….. “The conditions governing the performance of a contract may, in particular, concern social and environmental considerations”particular, concern social and environmental considerations
Article 53 allows the Contracting Authority to weight the various awarding criteria of which “environmental characteristics” may be one
Annex VI 1(a) states that “technical specification [as per article 23] shall includeAnnex VI 1(a) states that technical specification [as per article 23].....shall include levels of environmental performance....”
OPW requirement for environmental cement
Section 2.4 “Sustainability” of tender documentation
“The OPW require the specification and use of more environmentally friendly cements in publicly funded construction projects, in compliance with EU procurement and environmental p j , p ppolicies.This will involve the partial replacement of Portland Cement by existing waste products to yield significant improvement in theexisting waste products to yield significant improvement in the environmental performance of concrete*.”
*Directive 2004/18/EC: Procedures for Award of Public ContractsDirective 2004/18/EC: Procedures for Award of Public Contracts
Sustainable development is "development that meets the needs of thepresent without compromising the ability of future generations to meet theirown needs“
Recycled by-product – No new raw materials usedRecycled by product No new raw materials used
Durability – Longer life span
Significantly Lowered CO2 Emissions
“The most sustainable building material in the world”
Embodied CO2 Embodied CO2 and the Builtand the Built GGBS: The Best Technology for aand the Built and the Built EnvironmentEnvironment
Embodied CO2f 19%
GGBS: The Best Technology for a Substantial Reduction of Embodied CO2.
accounts for 19% of overall CO2emission in the UK*
GGBS can replace 55% of ordinary cement.
• GGBS will reduce the embodied carbon footprint of concrete by 50%UK*
GGBS is the BAT
carbon footprint of concrete by 50%.
• GGBS will reduce the embodied carbon footprint of a typical building by
for reducing embodied CO2.
25%.
GGBS is the Best A ailable Technolog*Potential for Reducing the Environmental Impact of Construction Materials commissioned by the BioRegional Development Group in association with Stockholm Environmental
GGBS is the Best Available Technology (BAT) to reduce the embodied carbon footprint of the built environment.
Institute and the WWF (UK study)
Properties &Properties &Properties &Properties &Advantages of using GGBSAdvantages of using GGBS
Same constituents as OPC
Different proportionsLess CaO
iMore Si02More Al2O3
GGBS cement replaces ordinary Portland cement on a one-for-one basisNo change in any other element of the mix design:
sandaggregates
/ i ( b d d)w/c ratio (can be reduced)Admixtures
C t f tConcrete manufacture
Batch duration is the sameAllowable time to transport is extended – this increases with increasing percentage of GGBS
Engineering benefits start at 30%U i f 30 t 85%Usage varies from 30 up to 85%Most often specified at 50%
Treated same as Portland cement concreteNo adjustment striking timesAs always curing to comply with BS 8110 (as with all concrete proper curing ensures best practice concrete is achieved)Placing, compacting and powerfloatingConcrete admixtures compatible.
Temperature controlpIssue reduces with increasing percentage of GGBS
More CSH gel More CSH gel –– Less CA(OH)Less CA(OH)22 –– Reduced Permeability/Porosity Reduced Permeability/Porosity
Placing, compacting and pumping easier:lower relative densitysmaller particle sizes
Powerfloating as normalSetting times longer by 1 – 2 hrs Sl t f bl diSlower rate of bleedingWater demand 3% to 5% lowerCompatible with admixturesCompatible with admixtures
More CSH gel More CSH gel –– Less CA(OH)Less CA(OH)22 –– Reduced Permeability/Porosity Reduced Permeability/Porosity
Vertical formworkMinimum 2 N/mm2
required to prevent mechanical damage
Horizontal formworkMinimum 10 N/mm2 or twice the stress to whichtwice the stress to which the slab is subjected
- At least 10 N/mm2 achieved after 3 days
- Use Temperature Matched Curing to confirm
More CSH gel More CSH gel –– Less CA(OH)Less CA(OH)22 –– Reduced Permeability/Porosity Reduced Permeability/Porosity
70.0
80.0
60.0
70.0
40.0
50.0
N/m
m2
20.0
30.0
0.0
10.0
Days0.0
7 28 90
100/0 Sept 50/50 Sept 30/70 Sept
More CSH gel More CSH gel –– Less CA(OH)Less CA(OH)22 –– Reduced Permeability/Porosity Reduced Permeability/Porosity
Chloride PenetrationChloride PenetrationLower chloride ion diffusivityLower porosity/permeabilityp y p y
Applications: roads and bridges, car parks, sea defences, marine structures.
More CSH gel More CSH gel –– Less CA(OH)Less CA(OH)22 –– Reduced Permeability/Porosity Reduced Permeability/Porosity
More CSH gel More CSH gel –– Less CA(OH)Less CA(OH)22 –– No CNo C33A A –– Reduced Permeability/Porosity Reduced Permeability/Porosity
Sulphate ResistanceSulphates react with C3A and Ca(OH)2 to form ettringiteSulphate Resisting cement (SRPC) has reduced C3A, but no reduced Ca(OH)2, and no reduced C3 , but o educed Ca(O )2, a d o educedporositySRPC cannot be used in marine environmentsGGBS much lower price than SRPC
• Note: In BS8500 the only option recommended as suitable for the most severe sulphate exposure (Class DC-sulphate exposure (Class DC4m) is concrete containing at least 66% GGBS
• Use of Sulphate resistant cement is not permittedcement is not permitted
More CSH gel More CSH gel –– Less CA(OH)Less CA(OH)22 –– No CNo C33A A –– Reduced Permeability/Porosity Reduced Permeability/Porosity
Advantages in wastewater treatment works
http://www.ecocem.ie/index.php?p=technical&q=wastewater
More CSH gel More CSH gel –– Less CA(OH)Less CA(OH)22 –– No CNo C33A A –– Reduced Permeability/Porosity Reduced Permeability/Porosity
GGBS lowers peak and overall heatReduces thermal stressingReduces micro-cracking (particularly useful in water retaining structures, basements, podium slab, bridges, stadiums, secant pile walls etc.)bridges, stadiums, secant pile walls etc.)Optimum substitution level 60 – 85%
60
50
60
40
20
30 Highest
Lowest
Difference
10
0
More CSH gel More CSH gel –– Less CA(OH)Less CA(OH)22 –– No CNo C33A A –– Reduced Permeability/Porosity Reduced Permeability/Porosity
GGBS is an off-white powderLi ht l d tLighter, more even-coloured concreteSmoother, more defect-free surfaceSuppresses/Eliminates efflorescenceLower pigment requirements – 20% savingGGBS can be used as partial replacement for white cement, up to 70%
GGBS cement, and OPC
Bridge pier and bridge deck, Enfield bypass
Bridge deck 100% OPCBridge deck 100% OPC
Bridge pier 50% GGBS
C k Ci i OffiCork Civic Offices
Cathleen Falls Bridge2006 ICS Design and2006 ICS, Design and Construction Awards
Sleeping Giant2007 ICS2007 ICS,
Design and Construction
Award
S O’C B ildi D bliSean O’Casey Building Dublin2008 ICS,
Design andDesign and Construction
Award
QE II bridge, Dartford M25QE II bridge, Dartford M25
5050--70% GGBS for chloride 70% GGBS for chloride resistance, reduced heat of resistance, reduced heat of hydration and appearancehydration and appearance
Second Severn CrossingSecond Severn CrossingSecond Severn CrossingSecond Severn Crossing
A i St di D bliAviva Stadium, Dublin
Father Collins Park DublinFather Collins Park, Dublin
Standard concrete specification containing GGBSp g
The world’s first Carbon Neutral Building Material launched in 2007 in partnership with the biggest names in the Irish Construction Industry:
T H ldiTreasury HoldingsPierseDurkan GroupMcNamaraJJ Rhatigan
Details on all prestigious projects can be found onwww.carbonneutralconcrete.ie
What is in it for you!
•Best durability (longer life)•Reduce lifetime maintenance costReduce lifetime maintenance cost
•Best sustainable material•Demonstrates your commitment to ya sustainable agenda•Create a lot of positive PR
•Best Architectural•Reduce cost to achieve desired finish
•Best value for money