Thermal Analysis of Hydrated Fly Ash-Lime Pastes

Fly ash is the ash precipitated from the exhaust fumes of coal-fired power stations. It consists mainly of active silica and alumina, with large amounts of glass. The aim of this work was to study the pozzolanic activity of fly ash with lime by means of DTA as a function of the lime content and the curing time. The curves revealed that the rate of hydration, as indicated by the residual lime and hydrated compounds, increases with increasing lime content and curing time. It is concluded that fly ash can be used as a blending material in pozzolanic cement.