Mechanical properties of photocatalytic white concrete subjected to high temperatures

The paper describes the consequences of progressive damage in architectural high performance concrete when exposed to different heating treatments. Specimens were tested for uniaxial compressive, direct, and indirect tensile strengths at ambient conditions approximately one day after the exposure to the high temperature. Modifications in the microstructure, porosity, and pore size distribution of the fire deteriorated specimens were identified using scanning electron microscopy and mercury intrusion porosimetry techniques. Test results revealed no significant variations in the mechanical strengths for specimens exposed to temperatures up to 250°C. Per contra, significant damage was observed for higher temperature, 500°C and 750°C, treatments, similar to that of ordinary concrete made with similar aggregates. Based on X-ray diffraction analysis, photocatalytic properties of the concrete were lost at 750°C.