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Monolith concrete insulated panel tilt-up system. CarbonCast High Performance Insulated Wall Panels. J U N E 2 0 2 3 | 9 Precast Concrete P H OTO G R A P H Y CO U RT E S Y NZ B U I L D ER S; A LT US G RO U P Precast concrete industry advances sustainability with innovative techniques and partnerships by ROBIN BRUNET W ith sustainability in the construction sector con- tinuing to be a vaguely defined value at best, it's no surprise that the precast concrete sector is singled out by some as a major contributor to carbon emissions. Fortunately, many people in the sector are fighting back, and their arguments for the use of precast as a sustainable building material are compelling. John Carson, executive director at AltusGroup, says, "There's lots of discussions about cement being a high carbon material, but concrete buildings last an awfully long time, several hundred years or more if constructed properly." Carson offers practical advice to carbon-con- scious designers. "The best way to reduce the embedded carbon in a precast concrete wall panel is to reduce the amount of cement used. CarbonCast panels with carbon fibre grid reinforcing and inte- grated insulation can reduce concrete use by 30 percent or more compared to solid panels. Also, the thermal efficiency of the panels results in higher R-values than other technologies, which reduces operational carbon." Carson adds, "While continuing to come under attack from wood enthusiasts and environmen- talists for its carbon dioxide [CO2] footprint, the concrete products industry has made significant strides in CO2 reduction. Today, CarbonCast precast concrete enclosures using composite design remain one of the most effective ways to create long-lasting fire safe structures, and we have been doing so for nearly 20 years." As for the state of the precast market in 2023 overall, Carson says, "The North American mar- ket remains robust, and some precast producers are booked into 2024. Novel architectural facade aes- thetics, unique structures, and mixed-used projects including retail, housing, and parking are drivers. Data centres and distribution continue to lead pre- cast growth in select metro regions." However, he adds that while few projects have can- celled as a result of rising interest rates, "it remains an industry concern. Inflation and rising material costs, increased labour cost, and material supply chain are still key concerns. Global cement supply and type is a primary concern to precasters currently." Lafarge Canada has made a huge commitment to achieving sustainability across its production facilities and with its products. Its latest initiative is an agreement with TransAlta Corporation (which owns, operates, and develops a diverse fleet of elec- trical power generation assets in Canada, the U.S., and Australia) to advance low-carbon concrete proj- ects in Alberta. The new project will repurpose landfilled fly ash, a waste product from TransAlta's Canadian coal-fired electricity operations west of Edmonton, which ended in 2021. The ash will be used to replace cement in concrete manufacturing. Landfilled fly ash must first go through a ben- eficiation process in order to be used in concrete; this project will utilize the Ash-TEK Ponded Ash THE BUILDING BLOCKS OF CONSTRUCTION

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