MECHANICAL PROPERTIES OF HIGH STRENGTH CONCRETE AT HIGH TEMPERATURES

Abstract

Effects of elevated temperature exposure and various factors, including water-to-cementitious materials ratios (w/cm), curing conditions, heating rates, test methods, and polypropylene (PP) fibers, on (l) pore pressure buildup and potential for explosive spalling and on (2) degradation of mechanical properties in normal strength (NSC) and high-strength concrete (HSC) are presented. Degradations of mechanical properties were measured using 100 x 200 mm cylinders, heated to temperatures of up to 600C at 5 C/min, and compared with results of other studies and existing codes. Pore pressures were measured using 100 x 200 x 200 mm blocks, heated to 600C at 5 C/min and 25C/min. Experimental evidences of the complex, temperature-dependant moisture transport process. which significantly influenced pore pressure and temperature developments are described.