Microstructural evolution of belite-rich cement mortar subjected to water, carbonation, and hybrid curing regime

The present study investigates the influence of various curing schemes on the strength and microstructural evolution of belite-rich cement (BRC) mortar. The sets of BRC mortar were subjected to different carbonation and/or water curing for 28 days. The mineralogical changes in BRC depend upon the w/c ratio of the mix and CO2 concentration at the initial days of curing. Ettringite, portlandite, and unreacted belite were the hydrated phases at a 0.3 w/c ratio. Regardless of curing type, rapid mineralogical changes at higher w/c ratios through different polymorphs of CaCO3 and de-calcified silica gel were observed. The carbonation curing was efficient for higher strength development at all the w/c ratios (0.3–0.7). However, hybrid curing was more efficient than water curing at higher w/c ratios (0.6 and 0.7) in improving the compressive strength.