Influence of natural Pozzolan and blast furnace slag on hydration and physico-mechanical properties of cement

This study presents the hydration mechanisms and physico-mechanical characteristics of cements composites based on Portland cement, natural Pozzolan (PZ) and blast furnace slag (BFS). The Vicat test indicates a reduction in the initial setting time. X-Ray Diffraction (XRD) analysis was used to evaluate the pozzolanic reactivity of mineral additions. The curve of heat released of M20 (20% PZ, 80% cement), shows that the dormant period was shortened by a rapid resumption of hydration reactions compared to the control. The mechanical activation, combined to the thermal activation has significantly increased the strength at early and medium term. The micrographs obtained by Scanning
Electron Microscopy (SEM) show greater compactness in blended cements and a change in microscopy and pore’s structure depending on the additions and curing temperature.