Shaw Brick leads CO2-based concrete masonry curing demonstrations

Source: CarbonCure Technologies, Halifax, N.S.

By Don Marsh

Nova Scotia-based Shaw Brick has scheduled a spring launch of CarbonCure block, a CSA-grade unit that uses carbon dioxide in the molding cycle to improve compressive strength development.

The producer is the premier user of a system from CarbonCure Technologies in which concrete masonry units become CO2 sinks, sequestering the gas in mineral form as they cure. The process enables producers to promote blocks’ carbon-capturing function and reduced energy consumption attributable to cement-optimized mix designs and lower steam requirements for curing.

“We are already seeing orders for the product and expect to announce a deal with a national builder for preferred block specification,” says CarbonCure CEO Robert Niven. “CarbonCure blocks are indistinguishable from standard gray block, and have commanded specification from architects and government agencies, along with encouraging building-owner response.

“The curing system is profitable without its green marketing or potential carbon credit value. Ultimately we provide customers two sources of value—higher early strength and green product differentiation. Each plant operator may profit from higher strength differently. For instance, reducing cement content, cull rates, curing temperature, inventory time/handling, or achieving lower unit density.”

CarbonCure is unlike past CO2-based curing equipment, Niven adds, since carbonation occurs in the product machine’s mold box rather than in the kilns—the latter prone to corrosion from the CO2 exposure. CarbonCure engineers customize and install systems for optimal performance, leaving existing equipment, operating standards and materials mostly unchanged.

As Shaw Brick eyes field deliveries, Atlas Block Co. in Hillsdale, Ontario, and Basalite Concrete Products in Dixon, Calif., are set for their own CarbonCure Block System demonstrations by mid-year. CO2 supplier Air Liquide provides a skid-mounted gas delivery system that integrates with concrete plant controls; gas is fed into the production process through CarbonCure’s proprietary molds.

A full report on CarbonCure appears in Concrete Products’ February digital edition (scroll to pages 16–17).