Heat – Resistant Binder Using Fly Ash

About 15 million tons of coal ash are generated by thermal power plants in Vietnam each year. Solving the amount of this discarded stuff is a problem for building material industry. This paper presents a research on the use of ordinary Portland cement (OPC) and discarded stuff in industry as fly ash (FA) to make heat-resistant binder. Nine different composite mixtures with varying amounts of FA are exposed to high temperatures of 100, 200, 400, 600, 800 and 1000oC. Physical and mechanical properties including compressive strength, density, shrinkage are determined after air cooling. Micro-structure is investigated by thermo- gravimetric analysis (TGA), X–ray diffraction (XRD) and scanning electron microscopy (SEM) tests. Based on factorial experimental design, we have determined the optimal composition of heat – resistant binder. The OPC is partially replaced by 25,014%, and 40,033% of FA can be used as heat–resistant binder at high temperatures 800 oC and 1000oC