CO2 Utilization in Precast Concrete

Production of cement is a major source of industrial CO₂ emissions. In recent years, numerous studies have focused on various means of reducing the CO₂ footprint of cement-based materials. The present study is related to accelerated carbonation curing technology as a direct mean of reducing the CO₂ footprint by simultaneously utilizing and sequestering it in cementitious products during the curing stage to produce concrete products with enhanced properties and high CO₂ uptake.

Steam curing of cement is commonly used method in manufacturing precast concrete to achieve high early strength. Meanwhile, accelerated carbonation curing produces concrete products with enhanced properties such as sulfate and acid resistance as well as mechanical strength.

In this study, we found that the simultaneous CO₂ and steam curing of precast cement mixture had ~20wt.% CO₂ uptake in cementitious materials, which is almost 5 times higher than the uptake of conventional industrially practiced curing under only steam. Furthermore, the proposed method resulted in 32% increase in the early compressive strength, and that the targeted mechanical strength under the proposed method was attained within 7 days, in comparison to 28 days under the conventional industrial curing practice.