Carbon Fixation Characteristics and Performance Enhancement of CO2 Mineralized All-solid Waste Alkali-activated Cementitious Materials

CO2 mineralized all-solid waste alkali-activated cementitious materials can not only realize the storage of CO2 mineralized, but also shorten the curing cycle of alkali-activated cementitious materials and improve their compressive strength. It is a promising way of CO2 capture and utilization. The effects of the ratio of alkali-activated cementitious materials, mineralized curing pressure and mineralized curing time on the carbon fixation rate and compressive strength of CO2 mineralized cementitious materials were studied. The results show that the calcium carbide slag as alkali activator is more suitable for mineralization curing, and the sample with the highest Ca/Si ratio has the best carbon fixation ability under the same curing condition. Increasing the curing pressure and curing time of CO2 can improve the properties of the samples. Physical and chemical characterization test results show that, the microstructure of the mineralized samples is more compact than that of the natural curing samples, and the calcite-type calcium carbonate produced in the curing process is helpful to increase the compressive strength of the material. The research results provide basic data and reference for the development of CO2 mineralization curing technology of all-solid waste alkali-activated cementitious materials.