Understanding the hydration of dolomite in cementitious systems with reactive aluminosilicates such as calcined clay

By S. Krishnan, Shashank Bishnoi. Cement and Concrete Research, 2018

177 citations recorded by the source corpus.

Abstract This study investigates the hydration of dolomite, CaMg(CO3)2, with calcined clay in presence of calcium hydroxide and ordinary Portland cement. The hydration products as well as the microstructure at various ages were characterized using X-ray diffraction (XRD), thermogravimetric analysis (TGA), and mercury intrusion porosimetry (MIP). Isothermal calorimetry was used to understand the reaction kinetics. The systems with dolomite were compared against control systems with limestone and quartz. It was seen that, the formation of carbonate – AFm phases takes place in the dolomite systems similar to limestone systems. No formation of brucite (Mg(OH)2) was observed till 90 days of hydration, with Mg2+ ions most likely being incorporated into hydrotalcite phase (Mg4Al2(OH)14). The synergetic effect observed in the Portland cement – calcined clay – dolomite system was found to result in a refined pore structure at early ages and improvement in the mechanical properties such as compressive strength.

Subfields: Civil and Structural Engineering, Materials Chemistry

View Paper: https://www.semanticscholar.org/paper/99eacb3c69efe20db0e781855eb2ab54ed281c13