In-Situ X-Ray Diffraction Carbonation of Cementitious Silicates

Carbonated mono-calcium silicate or carbonate cement has the potential to bring the cement industry to the next level by simultaneously providing a more stable alternative to traditional Portland cement and by reducing the carbon footprint of cement production. Carbonate cement replaces the key strength-imparting hydrating minerals, di-calcium (Ca₂SiO₄) and tri-calcium (Ca₃SiO₅) silicate, with mono-calcium silicate (CaSiO₃), which utilizes carbon dioxide instead of water to chemically bond the CaSiO₃ grains. In this work, we analyze the curing kinetics of carbonate cement by monitoring the crystallization of calcium carbonate (the product of CaSiO₃ carbonation) via in-situ x-ray diffraction We assess the kinetic differences of carbonation between synthetic and naturally occurring CaSiO₃. Semi-quantitative x-ray diffraction techniques are combined with thermal analysis measurements to accurately measure reaction progression.