关键词: 混凝土;高温;气体渗透性;耐久性;力学性能

Abstract: High temperature of fire hazard not only reduces the mechanical properties of concrete structure,but also has significant impact on the durability of concrete.The gas permeability, elastic modulus and axial compressive strength of concrete under high temperature were studied by simulating fire test at high temperature resistance furnace,and the relationship between gas permeability and mechanical properties was studied.The results show that the concrete gas permeability gradually increases with the fire temperature and increased by 72.6 times at 500 ℃.The elastic modulus and compressive strength of the concrete were slightly improved at 200℃,and the mechanical properties of the concrete were greatly reduced at 350 ℃and above.

Key words: concrete;high temperature;gas permeability;durability;mechanical property