Splitting Tensile Strength of Fly Ash Activated by Hydrothermal Hot-Pressing Process

Abstract

Fly ash is normally solidified by strong alkaline solutions at room or moderate temperatures. In this study, an innovative process of recycling fly ash (both Class F and Class C) into potential construction materials with superior mechanical properties is investigated. This innovative process involves chemical activation, hydrothermal reaction (hence, heat and moisture), and hot pressing. The emphasis is on the synergistic effects. Several key parameters—such as treatment temperature, duration of process, and amount of chemical activator—are evaluated critically. The results confirm that fly ash can be solidified and specimens show splitting tensile strengths of about