Conclusion
CMUs have been in use for approximately 120 years. The article has demonstrated the embodied carbon of concrete block can be reduced, whether passively through natural weathering carbonation or by precarbonation using modern technology cure concrete block using CO2. EPDs, both nationally averaged and plant-specific, are now available for concrete block masonry products. Embodied carbon has also been noticeably reduced in concrete block manufacture by the substitution of GUL for the general use and Portland cement GU, which has translated to a 7.7 per cent reduction in the GWP of concrete masonry products.
Recent collaboration with the University of Alberta has led to improved thermal bridging values for concrete block walls. These values were used to demonstrate that concrete block masonry can achieve net-zero energy requirements of 0.15W/m2 K for the opaque wall and 0.8W/m2 K for fenestration and doors, after thermal bridging in the opaque wall of the front elevation of an office building.
Determining the thermal mass effects of concrete block is already being accounted for in the U.S. code and is another way concrete masonry supports climate-friendly construction. Introduction of this into the NECB would be advantageous, not just for masonry, but for any material that exhibits thermal mass effects.
The masonry industry is committed to reducing its carbon footprint, from embodied carbon using innovative ways to reduce emissions during manufacturing, and in operational carbon by ensuring exceptional thermal performance in the envelope to reduce thermal energy use in buildings constructed with this resilient material.
Notes
1 Visit www.oneclicklca.com/lca-glossary-for-construction-infra-manufacturing.
2 Learn more about EPDs at ccmpa.ca/resources-publications/environmental-product-declaration.
3 See the ASTM standard, www.astm.org/stp164020210112.html.
4 Read the report, “Issues, Impacts, and Mitigations of Carbon Dioxide Emissions in the Building Sector,” at www.mdpi.com/2071-1050/12/18/7427.
5 Visit the online thermal catalogue at thermalenvelope.ca/catalogue.
6 Refer to the report at publications.gc.ca/collections/collection_2018/cnrc-nrc/NR24-24-2017-eng.pdf.
7 Visit Passive House Canada at www.passivehousecanada.com/downloads/Passivhaus_Primer.pdf.
8 See note 6.
9 See ncma.org/software/matss.
Authors
Mark Hagel holds a bachelor of science in actuarial science and applied mathematics, a bachelor of science in civil engineering, and a doctor of philosophy in civil engineering—all from the University of Calgary. Prior to employment with the Alberta Masonry Council, Hagel worked as a building envelope engineer and structural engineer with the Calgary office of Halcrow Yolles. His fields of expertise include thermal and hygrothermal modelling of building systems, corrosion modelling, life cycle cost analysis, structural analysis and design, and the durability of building components. In 2018, he served on the National Research Council of Canada’s (NRC’s) working group that developed the Guideline on Design for Durability of the Building Envelope; and in a working group on the CSA-S478-2019, Durability in Buildings. He can be reached at markhagel@albertamasonrycouncil.ca.
Mike Lafontaine is a key account manager with Oldcastle APG Canada West. He holds the following designations: CTR, SSG, SD. Lafontaine previously owned an advertising company with locations in Alberta and B.C. He can be reached at mike.lafontaine@oldcastle.com.
