Integration of carbon sequestration into curing process of precast concrete.

The feasibility of integrating carbon sequestration into the curing of precast concrete products was investigated. Research assessed the CO2 uptake capacities of carbonation-cured concrete masonry units (CMU), concrete pavers, fibreglass-mesh reinforced cement board, cellulose-fibre board, and ladle slag fines. Three curing systems were used: (i) an open-inlet system using pressurized recovered CO2; (ii) a closed system using pressurized flue gas with 14% CO2; and (iii) a closed system using dilute CO2 under atmospheric pressure. The amount of carbon dioxide that could be sequestered in the annual North American output of the various precast concrete products was estimated. The net efficiency was calculated accounting for CO2 emissions penalty resulting from the capture, compression, and potential transport of the curing gases. Carbonation curing of the considered products could result in a net annual CO2 sequestration in US and Canada of approximately 1.8 million tonnes if recovered CO2 is used and one million tonnes if flue gas is used. [ABSTRACT FROM AUTHOR]