INSPIRE data specification on Geographical Names - Guidelines
Essential Guidelines for Specification. -...
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ConcreteEssential Guidelines for Specification.
Cement Concrete and Aggregates AustraliaIStruct-E PresentationMay 2014
About CCAA• Not-for-profit organisation• Funded by cement, concrete and aggregate
producers of Australia• Founded 1928 by cement producers• Re-formed 2003 by combining with premixed concrete and
extractive industry sectors• Foundation members :
• Boral ; Holcim ; Hanson ; Adelaide Brighton Cement; CementAustralia;
• Over 60 Associate and Ordinary members• Ability Building Chemicals, BASF Construction Chemicals• Barro Group Pty, Gosford Quarry Holdings
What does CCAA do?
• Provides technical information and project supportto the Australian construction industry.• Publications include technical data sheets to major
texts• Concrete technology dedicated library• Direct representation through professional staff
• Participates in research, codes and standardsdevelopment.
• Represents its member companies' interests ingovernment relations.
CCAA Office locations
• Regional Offices• Brisbane• Sydney• Melbourne• Adelaide• Perth
• 28 full time staff across Australia
Concrete – a brief history• Romans first used un-reinforced
concrete to build some of their iconicstructures.
• Pantheon – re-built in AD 117-125 byHadrian is still regarded as one of themost magnificent concretestructures.
Concrete – a brief history• Fall of Roman empire …Decline of concrete use –
Alternatives – Timber, Stone etc.
• 1824 Portland Cement patented
• 1880s Development of Reinforced Concrete in Europe(pioneered by the French) using iron bars [Wilkinson/Coignet/ Hennebique]
• By 1910 reinforced concrete had been used in approx40,000 structures
Concrete constituents• Aggregates
• sand (fine aggregates)• coarse aggregate
• Cement (the binder)• Portland cement• Supplementary cementitious materials (waste by-products from
industry) :• Flyash; Blast Furnace Slag; Silica Fume
• Water (for cement reaction - hydration)• Chemical additives
?? What is concrete ??
What are the most important properties ofconcrete?
• Workability• The ability to place, handle, compact and finish
• Cohesiveness/Segregation• Strength
• Compressive• Flexural
• Durability• Density• Porosity, resistance to corrosive attack
Are Aggregates Just a Filler?
• Aggregates make up the
majority of the concrete
volume
• They are not just a “filler”
• They affect the workability,
strength and durability
Aggregate Strength
Aggregates mustbe strong enough
to handle the loads
Aggregates must also beable to withstand the
effects of the environment
e.g. weather and traffic
Aggregate Sizing
Good concreterequires the smallerparticles to fill theholes between thecoarser particles
Materials in concrete i.e.cement , gravel and sandare the ingredients for themix.
They must be the right type
They must be the rightquality
They must be combined inthe right proportions
They must be mixedthoroughly
Less Desirable
More Desirable
Particle Shape &Texture
X
LIME from Limestone/ChalkSILICA from Clay/Shale/SandALUMINA from Clay/Shale/BauxiteIRON OXIDE from Clay/Shale/Ironstone
What are the ingredients of cement?
Limestone
Ironstone sand shale
clayother
Cement ManufactureRaw mill
Raw MillSilo
Rotating Kiln
Clinker Silo
Cement Mill Cement Silo
Bulk 90%
Bagging 10%
Clinker
Preheating
Limestone Other materials
Gypsum and/or SCM
RawMaterial
1400oC
Supplementary Cementitious Materials
• What are SCM’s• Pozzolanic material which react with by-products
of Cement hydration• This changes the properties of the concrete in
both the plastic & hardened state• Important to keep in mind for highly substituted
mixes.
Supplementary Cementitious Materials [SCM’s]
Ground Granulated Iron Blast Furnace Slag• Formed at high temperature in iron blast furnace• Slight cementing reaction with water
Fly Ash• Collected from flue gasses in black coal burning
power stations• No cementing reaction with water
Silica Fume• Naturally occurring (mined)• Silica Fume (Ferrosilicon industry)• No cementing reaction with water
MODERN SCM’s
Fly ash• Collected from the flue gases at
black coal burning powerstations
Ground GranulatedIron Blast Furnace Slag• A waste removed from the
operations of blast furnacessmelting iron ore
Amorphous SilicaSilica Fume• Collected from the
refining of silicon metal
There is naturally occurringamorphous silica available in
other parts of the world includingNew Zealand and some is used in
Australia
Fly ash Reaction
Fly ashand Water
Portland Cement andWater
Fly ash and Lime
Slag Reactivity
Slag requires accelerator to be useful in concrete
Reacted Portland cement components provide accelerator
CCAA Concrete Technology Course
CONCRETE SPECIFICATION ANDSUPPLYTony Cooper
Standards Road MapAS3600 and component material standardsAS3600
Design of ConcreteAS1379
Supply of ConcreteAS1379
Supplement 1AS3600
Supplement 1
AS3972 CementAS3582 SupplementaryCementitious MaterialsAS2758 AggregatesAS1478 Admixtures
Constituent Materials
AS1012 Concrete
Sampling and Testing
AS3600:How Component Materials are Called Up• AS3600 defers to
AS1379 for concretespecification(Specification andSupply of Concrete)
• Two classes• Normal Class• Special Class
• AS1379 refers to• AS3972 (Portland and
Blended Cement)• AS3582 (SCM’s for use with
Portland and BlendedCement)
• AS1478 (ChemicalAdmixtures)
• AS2758.1 (Aggregate andRock for EngineeringPurposes)
• AS1012 (Testing)
Normal (N) Class Concrete:AS1379• N Class concrete
• Can be over 50% ofvolume of concrete ona project
• Deemed to complytesting options inAS1379
• N Class Concrete inAS3600• 20 MPa• 25 MPa• 32 MPa• 40 MPa• 50 MPa
Normal (N) Class Concrete Specification inAS3600 and AS1379• 20 MPa to 50 MPa• Slump
• 20 mm to 120 mm• 10 mm increments having different tolerances
• Maximum Aggregate Size:10 mm, 14 mm or 20 mm
• AEA: Up to 5%• Placement method: chute or pump• Density: 2100 to 2800 kg/m3
Special Class Concrete:AS1379• S Class concrete
• Addresses specific designrequirement (other thanNormal Class)
• More complex• Testing requirements need
to be specified in design• New designations of 65
MPa, 80 MPa and 100 MPaare all Special Class
• S Class Concrete inAS3600• 20 MPa• 25 MPa• 32 MPa• 40 MPa• 50 MPa• 65 MPa• 80 MPa• 100 MPa
Concrete Specification: Summary• AS3600 references AS1379 for specification• Two classes of concrete in AS1379,
Normal and Special Class• New grades of 65 MPa, 80 MPa and 100 MPa are
all Special Class• Testing requirements need to be specified for S
Class concrete as N Class provisions may notapply
The increasing frequency of low shrinkagespecifications in various projects• Shrinkage specifications may not be achieving the specific
outcomes intended by designers
• Over-emphasis in correlating drying shrinkage test results to thein-situ structural element behaviour
• Increased material cost imposed upon the client for littlebenefit
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Brief history of concrete drying shrinkagespecification in Australia
• Initially the Association of Consulting StructuralEngineers (ACSE) of NSW used shrinkage specificationsas a means of excluding dimensionally unstableaggregates in projectsNote: The current AS1379 max 1000µε N Class limit aims to
achieve this objective
• The Drying Shrinkage test was not originally intendedto be used as an incremental measure of a specificconcrete characteristic
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Drying Shrinkage Test Method Explained
• Accelerated test method• 7 days initial curing at 100% Relative Humidity• Followed curing at 50% Relative Humidity & 23oC.• Measurements are taken at 1, 2, 3, 4, & 8wk• 3 of 75mm x 75mm x 280mm specimens with
embedded studs.
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Moulding Shrinkage Bars (3)
33Studs
Stripping and Initial Curing
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Horizontal Comparator
Shrinkage Bar locatedfor measurement
Drying Shrinkage is calculated by:
Strain = Length reductionOriginal length
i.e. 650µε = 0.65mm/m• For a further explanation refer- CCAA publication:
• ‘Drying Shrinkage of Cement and Concrete’ (July 2002)’
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Typical National test resultsCommercial 20mm pump mix designs
• Brisbane average 700µε• Range 550-900µε
• Sydney average 650µε• Range 600-900µε
• Melbourne range 600-1000µε• Adelaide range 700-1000µε• Perth range 600-1200µε
For 10mm aggregate ~ add 150µε
CCAA Publication‘Drying Shrinkage of Cement and Concrete’ (July
200237
What affects drying Shrinkage
Measured drying shrinkage is dependent on:• Water loss rate/quantity
• External: Environment & surface area/volume• Internal: Water content & Permeability
• Restraint• External: Design & detailing• Internal: Agg qty, size, modulus, bond
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Would Concrete Crack in Space??
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AS1012.13 Test Method - Disadvantages
• Poor correlation to in-situ performance due to:• Early-age volumetric changes (strains)• Plastic shrinkage
• Hydration (autogenous) shrinkage• Temperature• Settlement• Other factors
• Standards/design do not account for these early-age strains
• Test does not measure early-age (0-7 days) volumechange
• Poor repeatability• Lab results typically varies by ±10% (~ 120µε spread)
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SPECIFYING FOR SUSTAINABILITYGBCA Concrete Credit – Komal Krishna
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WHATCHANGES HAVEBEEN MADE TOTHE GREENSTAR RATINGTOOL?
INNOVATION
RATING
10 - 19 pts – One Star20 - 29 pts – Two Stars30 - 44 pts – Three Stars45 - 59 pts – Four Stars
“Best Practice”
60 – 74 pts – Five Star“Australian Excellence”
75+ pts – Six Star“World Leadership”
ASSESSMENT CREDITS
Indoor Environment QualityEnergyTransportWaterMaterialsLand use and EcologyEmissions
ISSU
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ATEG
ORY
SC
OR
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ENVI
RO
NM
ENTA
L W
EIG
HTI
NG
S
SIN
GLE
SC
OR
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STRUCTURE OF RATING TOOL
Source: Cement Concrete & Aggregates Australiaweb: http://www.ccaa.com.au/LCA
Contribution ofConcrete
Contribution of“Cement”
~140 points available 3 points in MAT-4
Total Emissions Profile –Office Building
WHY ONLY 3 POINTS FOR CONCRETE?
93%
4%
3%
Operations Construction Maintenance
47%53%
Concrete Other materials
70%
30%
Cement Other materials
REVISION OF MAT-4 CONCRETE
REVISIONS•New Aim•Concept of PortlandCement•New pointsbenchmarks•No distinctionregarding concretesystem employed•New benchmarks forreclaimed water,coarse and fineaggregate•Reporting requirementusing structuralengineer
GP Replacement1 Point = 30% Insitu
20% Precast15% Prestressed
2 Points = 60% Insitu40% Precast30% Prestressed
3rd point = at least one of theabove
+ 20% RCA++100% Recycled in
non-structural
GP Replacement1 Point = 30% Average
across all mixes2 Points = 40% Average
across all mixes3rd point = 50% Reclaimed
water AND40% Coarse AggOR25% Fine Agg
PROVIDED GP does not needto be increased by >5kg/m3 toachieve desired properties.
Standardised spreadsheets will be provided in CCAA“User Guide” and available from www.ccaa.com.au
EXAMPLE CALCULATIONS PROVIDEDProject Name
Strength grade Volume in Project(following AS 1379) (m3) kg/m3 Total (kg) kg/m3 Total (kg)
MIX 1 20 300 280 84,000 128 38,475MIX 2 32 800 360 288,000 166 133,000MIX 3 32 4400 360 1,584,000 238 1,045,000MIX 4 40 290 440 127,600 247 71,630MIX 5 50 90 550 49,500 295 26,505MIX 6 65 100 550 55,000 333 33,250
TOTAL 5980 2,188,100 1,347,860
AVERAGE 423 234
Reference Case Average Cement Content 423kg/m3
Actual Average Cement Content 234kg/m3
Reduction in Cement Content 189kg/m3
% Reduction in Cement 38.4%
Credit Points eligibility 1
TYPICAL 12 STOREY CONCRETE CONSTRUCTION
PORTLAND CEMENT REDUCTIONPortland cement contentReference Case
Portland cement contentActual Project
Construction Solutions
Designing for sustainability• Application dependent• Low risk/ non-structural elements vs Critical elements
• Precast• Efficiency, Speed, Cost
• Pixel Building - Grocon• post-tensioning ‘green’ concrete
Environmental impact
TimeCost
Supply Considerations
• Good supply capabilities inVictoria
• Product quality – possiblevariation
• Concrete producer needs to have theability to store various materials
• Technical and logistical support
Supply of SCM to Victoria
GGBS - Japan
Mineral Addition
• Mineral additions are defined in AS 3972 as fly ash, slag andlimestone.
• CCAA Studies show – addition of up to 10%• Potential Saving of 375,000 – 750,000 t of CO2 emissions p.a.• Changes adopted in AS 3972 (2010) – allowing max 7.5% mineral
addition in GP• GL cement introduced – max 20% mineral addition• Major suppliers in Vic currently using GP cement allowing for
maximum mineral addition• Included in revised GBCA credit.
Considering the use of recycled materials in construction
PerformanceFit for purposeSustainability
Durability
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QUESTIONS??THANK YOU
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CONTACT: CCAAKOMAL KRISHNAEngineer , Construction SolutionsT: (03) 9825 0200D: (03) 9825 0225E: [email protected]