Studies on some factors affecting CO2 curing of lightweight concrete products

This paper deals with the effects of several factors, such as CO2 pressure, curing time, water-to-cement ratio and continued curing after CO2 curing on temperature profiles, CO2 curing degree and strength of concrete. Results indicated that the accelerated reactions between CO2 and cement minerals happen mainly during the first 15 min regardless of CO2 pressure and pre-conditioning environment. CO2 curing degree and strength increased as the CO2 pressure and curing time increased. The concrete specimens should have a water-to-cement ratio greater than certain value so as to facilitate the moulding of concrete products and to achieve a high CO2 curing degree. CO2 cured specimens will continue to gain strength due to the hydration of cement minerals unreacted during the CO2 curing if the specimens are kept in moist environment.