Effect of carbonation curing on physicochemical properties of mineral admixture blended belite-rich cement

Abstract

The present study investigates the effect of CO2 curing on carbonation degree, CO2 uptake, mechanical and physicochemical properties of mineral admixtures blended with belite-rich cement (BRC). Pulverized coal combustion (PCC) ash, circulating fluidized bed combustion (CFBC) ash, and blast furnace slag (SG) were utilized as mineral admixtures. The results revealed that the PCC ash blended with BRC attained the highest compressive strength under CO2 curing. CFBC ash was comparable to PCC ash in terms of the ability to improve the mechanical and physicochemical properties. TG analysis revealed that CFBC ash blended BRC was excellent for promoting carbonation and CO2 uptake. TG, MIP, XRD, and 29Si NMR results showed that the SG was the least reactive mineral admixture with BRC under CO2 curing and negatively affects the strength attainment outcome, carbonation degree, and CO2 uptake. 29Si NMR confirmed the potential of PCC ash and CFBC ash in enhancing the reactivity of BRC under CO2 curing than the SG. Therefore, it is concluded that the blending of PCC ash and CFBC ash is beneficial in promoting the CO2 sequestration characteristics and compressive strength of BRC.