Fast Set and High Early Strength Cement from Limestone, Natural Pozzolan, and Fluorite

Fast set and high early strength cements containing calcium fluoroaluminate phase (C11A7CaF2) are usually produced by sintering a proportioned raw mix from calcareous and argillaceous components as the main raw materials, at reduced temperatures about 1330°C. In this work, the possibility of utilizing natural pozzolan as the argillaceous component in the cement raw mix and in order to decrease the sintering temperature of fast set and high early strength cement clinker containing C11A7CaF2 phase has been investigated. The results reveal that the sintering temperature can be reduced to temperatures as low as 1270°C by utilizing a suitable natural pozzolan and improving the mix burnability. The experimental results confirm the possibility of achieving final setting times as low as 10 min and 3 day compressive strengths as high as 57 MPa