中文摘要：

完成了127块100mm×100mm×515mm混凝土棱柱体试块在20～900℃条件下的高温试验和高温后的弯折试验．以C40普通混凝土作为参照，考察了C50，C80和C100高性能混凝土棱柱体试块在火灾中的特点；通过对强度等级、外掺聚丙烯纤维和外掺矿渣与硅灰等因素的对比，分析了高性能混凝土高温后残余抗折强度与经历温度之间的相互关系；提出了高性能混凝土高温后残余抗折强度与经历温度间统计公式．

英文摘要：

Based on rupture tests on 127 cylinder specimens with a size of 100 mm× 100 mm× 515 mm at temperatures ranging from 20 ℃ to 900 ℃, the fire behaviors of highperformance concrete （HPC） with strength grades of C50, C80 and C100 are investigated with the normal concrete （NC） of C40 as the control. After the effect of blast furnace slag, silica fume as well as polypropylene （PP） fiber on the residual flexural strength of concrete is studied, and some differences are found between HPCs with different admixtures. Finally, a formula concerning the relationship between the residual flexural strength and the elevated temperature is proposed.