Influence of PP Fibers on the Relative Residual Splitting Tensile Strength of HSC after Exposure to High Temperatures

In order to discuss the effect of different cooling methods, dosage and length of PP fiber on the splitting tensile strength of PPHSC after high temperatures, experiments were carried out on the splitting tensile strength of C60 HSC mixed with PP fibers with different dosage(1.0kg/m(3), 1.5 kg/m(3), 2.0kg/m(3), 2.5 kg/m(3)) and length (8mm, 19mm) before and after high temperatures. The test results indicated that the relative residual splitting tensile strength of PPHSC totally declined with the increase of temperature, meanwhile, the strength value of HSC cooled in air was higher than that cooled in water on the whole. The addition of PP fiber with the length of 8mm contributed to the enhancement of the relative residual splitting tensile strength of HSC after high temperatures, whereas, only the HSC mixed with 1.0 kg/m(3) PP fibers had a greater strength than plain concrete when the length of fiber was 19mm. After exposure to high temperatures, the relative residual splitting tensile strength of HSC with PP fibers 8mm in length was completely higher than those with 19mm.