Fire and postfire compressive strength of recycled aggregate concrete made with ceramic stoneware

This study investigated the possibilities of reusing ceramic stoneware (CS) waste, a particular type of tiles ceramic waste (TCW), provided by a treatment plant in Castellon (east Spain), as recycled aggregate in structural concrete, and its influence on concrete behaviour when exposed to elevated temperatures (200 degrees C, 400 degrees C, 600 degrees C, 800 degrees C; compressive strength determined in hot and after air and water cooling). Although all samples exhibited similar strength values at room temperature, their thermal conductivity reduced with increasing CS contents. Strength values progressively dropped with rising temperatures, with the highest results recorded in hot, followed by air and, finally, by water cooling. Smaller differences between the strength registered in hot and after cooling were generally recorded in the recycled aggregate concretes (RAC) than in the reference sample. The concrete prepared with 100 vol% CS gravel was the only one to generally provide better residual strength after air-cooling than in hot.