The Concrete Masonry & Hardscapes Association (CMHA) provides global warming potential (GWP) and other requisite metrics for seven light, medium or normal weight block classes in the premier Industry-Average Environmental Product Declaration (EPD) for Concrete Masonry Units in the United States. Leading EPD author Climate Earth Inc. factors data from 35 CMU producers in the ASTM International-verified document.
The Industry-Average EPD for CMU charts GWP figures—kilograms of carbon dioxide equivalents (kg CO2 e)—by cubic meter of mix for each block class, ranging from 208 kg CO2e for normal weight block (2,000-3,240 psi compressive strength; density ≥ 125 pcf) to 395 for lightweight block with expanded shale, clay or slate manufactured aggregate (2,000-4,490 psi compressive strength; density ≤ 104.9 pcf). The figures reflect downward adjustments for estimated natural carbon sequestration volumes at 28 days, the EPD’s “at the gate” threshold or system boundary. They range from 18 kg CO2 e to 22 kg CO2e, respectively, for normal weight block of conventional (2,000-3,240 psi) and higher (≥ 4,500 psi) compressive strength mix designs. As supplemental information, the EPD cites estimated carbon sequestration volumes at two years, where the kg CO2 e is at least double the 28-day figures.
“The publication of the first United States EPD for CMU is a significant accomplishment for the industry,” says CMHA CEO Bob Thomas. “Members are committed to sustainability, and this EPD accurately quantifies environmental impacts. These results can be used to inform building materials environmental databases, influence decisions on building materials, and ensure that concrete masonry is seen as a sustainable building solution.”
CLIMATE EARTH PENS CARBICRETE EPD
CarbiCrete, Montreal developer of steel slag-based concrete binder plus companion carbon dioxide mineralizing process for block production and curing, has released its premier Environmental Product Declaration with an assist from California-based EPD author Climate Earth. Announcement of the document coincided with last month’s Concrete Masonry and Hardscapes Association’s Canadian Hardscapes Activities meeting in Montreal.
Verified by ASTM International under Concrete Masonry and Segmental Concrete Paving Product EPD Requirements, the declaration shows CarbiCrete CMU mixes as produced by Quebec hardscape operator Patio Drummond boast a Global Warming Potential figure of 11.7 kg of carbon dioxide equivalent per cubic meter of concrete—nearly 20 times lower than the industry average of 200-plus kg CO2e per 1m3 of portland cement CMU mix.
“This demonstrates the substantial impact that our technology has on reducing the CO2 footprint of concrete and the considerable value it provides to the construction industry and end users. The EPD enables them to make more informed comparisons to meet their sustainability goals,” says CarbiCrete CEO Jacob Homiller.
“CarbiCrete’s innovative approach—eliminating cement and drastically reducing CO2 emissions—sets it apart as a true leader in sustainable concrete,” adds Climate Earth CEO Chris Erickson. “By working together, we’re able to create product and site-specific EPDs showcasing these extraordinary carbon reductions. Different from industry averages, our EPDs capture the full impact of using local suppliers and recycled materials, empowering clients to highlight their sustainability efforts with clarity and precision.”
CarbiCrete and Climate Earth plan to co-host an early-2025 webinar offering an in-depth look at the life cycle assessment and EPD development processes, providing participants technical insights into how CarbiCrete achieves remarkable GWP reduction against portland cement CMU mixes. Also early in the new year, Port Colborne, Ontario-based Canal Block will begin producing CarbiCrete CMUs, extending their availability beyond the customary market radius Patio Drummond serves.
Document is posted at www.masonryandhardscapes.org.