EFFECT OF SILICA FUME ON THE PHASE-COMPOSITION AND MICROSTRUCTURE OF THERMALLY TREATED CONCRETE

The influence of elevated temperature on the microstructure of concret e is vital for fire-resistance studies. Silica fume tends to improve o rdinary concrete properties, due to its reaction with hydrated product s. This study aimed to investigate experimentally the change occurring in the phase composition and microstructure of concrete pastes contai ning silica fume after heat treatment. The temperature varied from 100 to 600 degrees C by increment of 100 degrees C for three hours period . The investigation was performed by means of the X-ray diffraction an alysis, differential thermal analysis and scanning electron microscope . The results of this investigation show that, additional hydration of unhydrated cement grains, recrystallization deformation and transform ation of CSH phases were occurred. Copyright (C) 1996 Elsevier Science Ltd