Study on the Hydration Behaviour of the Coral Sand Powder-Ground-Granulated Blast Furnace Slag-Portland Cement Ternary System

Recently, the studies on the application of coral sand in concrete construction attracted wide attention, especially in China. Coral sand and coral sand powder (CSP) can be used as fine aggregate and mineral admixture in concrete, respectively. The main component of CSP is calcium carbonate (CaCO3), up to 96%. However, the utilization of CSP in cement mortar will cause performance degradation. Ground-Granulated Blast Furnace Slag (BFS) be used to improve the property of CSP-Portland cement mortar. In this study, the coral sand powder-blast furnace slag-Portland cement (CSP-BFS-PC) ternary system had been used to produce cement paste and mortar. The hydration product of the CSP-BFS-PC ternary system are researched fundamentally by X-ray diffraction, and compressive strength are tested at different curing age. The results show that CSP can suppress consumption of C3A. 15wt.% BFS can offset the strength loss of cement mortar due to the substitution of CSP for cement (CSP less than 15wt.%), especially 7-28 days.