Pozzolanic activity of thermally and mechanically treated kaolins of hydrothermal origin

Abstract

This work investigates the effect of the mechanical treatment of kaolin on its pozzolanic activity. Three representative Greek kaolins and a commercial product were activated using thermal and mechanical treatment. The pozzolanic activity was evaluated on the basis of Chapelle test and was investigated by means of X-ray Diffraction, Differential Thermal Analysis and Infrared Spectroscopy. The results showed that mechanical treatment of kaolin results in gradual kaolinite distortion, amorphization and, accordingly, to a competitive pozzolanic activation to that of the respective thermally treated ones. The crystallinity of raw kaolinite adversely affects the pozzolanic activity of both metakaolinite and nanostructured kaolinite.