b'CARBON REDUCTIONEnvironmental These regional EPDs quantify theProductSimilar issues exist with artificially low prescriptive limits Declaration environmental performance of 23 ofConcrete Ontario Member Industry-Wide EPD foron the use of supplementary cementing materials (SCMs), themostcommonlyusedconcreteREADY-MIXED CONCRETEsuchasslagandflyashwhichcanofferdramaticCO2 mixdesignsintheprovinceand Pier 27, Toronto, Ontarioreductions. Prescriptive limits on SCM replacement values Architect: architectsAlliance Owner: Cityzen Development Group and provide users with both the averageFernbrook Homes hamstring the contractor and the concrete producer when benchmark values for each mix asitcomestocarbonreductionmixdesignoptimization. well as a table of results that showsFinally, aggregate makes up to 70 per cent of the concrete theimpactsofcementtypesandmix design and having close-to-market access to high-quality variouslevelsofsupplementarymaterials is critical for achieving both low carbon and a long cementing material (SCM) usage. service life.CARBON REDUCTION 4:ENSURE THAT YOU HAVE EXCELLENT QUALITY While the creation of region-specific industry average EPDs, along with the expanded development of concrete plant-specific EPDs, isCONTROL AND ASSURANCE ON YOUR PROJECTSa critical first step for benchmarking our carbon reduction in theWhilethisisimportantforallproducts,itisespecially coming years and decades, the pressing question that we all havecriticalforconcretebecausepoorconcretetestingcan to ask is, So what can I do now to significantly reduce the carbonleadtodrasticallyoverdesignedconcretemixestoavoid intensity of my concrete? liability issues. Concrete is made from local materials, and Lets start off with five things you can do today to implementitsperformancecanbeaffectedbyweatherconditions, a 10- to 30-per-cent reduction in your global warming potentialvariabilityofmaterials,delivery,placing,handlingand (GWP) as measured in kg CO2 per m3. testing. Although the materials used to make concrete meet rigorousstandards,thevariabilitycanbequitehighand 1: EMBRACE PERFORMANCE SPECIFICATIONS improper testing results in the use of more cement to offset WhiletheCSAA23.1/.2concretestandardstillallowsforimproper testing practices. prescriptive specification of concrete on Canadian construction5:CONSIDER THE USE OF BOTH INNOVATIVE projects, the vast majority of construction projects instead follow the performance option. Here the specifier indicates the long- MATERIALS AND EVALUATION METHODStermhardenedpropertiestheyrequirefromtheconcrete.TheWhileextremelysmallinvolume,concreteadmixtures contractor indicates the short-term construction properties thatcan have extremely dramatic impacts on the performance they need to effectively place and finish the concrete using theirpropertiesofconcreteandcarbonreduction.Manynew intended construction methods and work schedules.optionsexistwhencarbonreductionisaclearproject goal, and both longstanding and new chemical admixtures 2:ADD CARBON REDUCTION GOALS TO YOURareavailableforverysignificantmixdesigncarbon SPECIFICATIONS optimizations. There also are very significant and exciting There is significant wisdom in the business saying, If you cantdevelopments taking place around both carbon capture and measure it, you cant improve it. Specifications need to clearlycarbon-negative materials that are currently being showcased indicate to both the contractor and the designer the fact that carbonon projects around North America that offer the potential reduction is quickly becoming a critical design factor that everyonefor even greater carbon reductions in the future. needs to address. This is why Concrete Ontario developed our own Regional Industry Average EPD report and followed it up with ourInclosing,theuseofhigh-qualitylocalmaterials, guidelines for specifying low carbon concrete. combined with the active discussions between the owner, designer,contractorandconcretesupplieroncarbon 3:ALLOW THE USE OF LOWER CARBON RAW MATERIALS reduction options, will result in more sustainable concrete Asoutlinedinthefirstpoint,thecontinueduseofoutdatedconstruction that has a service life in excess of 75 years.prescriptive concrete specifications can dramatically increase the carbonintensityoftheconcrete.Formorethanadecade, the cement industry has been producingCRUSHING, WASHING,portland-limestonecement(PLC)asSCREENING,areplacementforGeneralUse(GU)RENTALScement.Whilethismaterialhasthe sameperformancepropertiesasGU cement, its carbon intensity is 10 per cent lower, and it is used in straight one-to-onereplacement.So,ifyou are still using a specification from the 1980s that prescriptively states only GUcementcanbeusedonyourA GUIDELINE FOR SPECIFYING 1118 Brodie Drive, Severn, OntarioL3V 0V2LOW CARBON READY MIXED CONCRETEIN ONTARIOproject, you have just taken a majorOCTOBER 2022| Fax: 705-326-0305carbonreductionoffthetablejstewart@jgstewart.ca |www.jgstewart.cabefore the project event starts. WINTER 2023AVENUES 29'