Abstract: In order to study the influence of polypropylene fiber on high temperature bursting and mechanical properties of C80 high strength high-performance concrete,the mechanical properties of C80HPC and C80PPHPC after high temperature were studied,and the relationship between axial compression strength, elastic modulus, splitting tensile strength and different fire temperature of C80HPC and C80PPHPC was analyzed. The test results showed that the axial compression strength, elastic modulus and splitting tensile strength of C80HPC and C80PPHPC all decrease with the increase of fire temperature,and the axial compression strength and splitting tensile strength of C80PPHPC are slightly higher than that of C80HPC. Before 200 ℃,the elastic modulus of C80PPHPC was slightly larger than that of C80HPC. Under the action of high temperature of 300~600 ℃, some specimens of C80HPC burst, but none of C80PPHPC burst, indicating that adding polypropylene fiber can inhibit the bursting and reduce the damage of high temperature to the mechanical properties of HPC.

Key words: high performance concrete, polypropylene fiber; high temperature, mechanical property