Abstract: In order to study the mechanical properties of basalt-cellulose hybrid fiber concrete after high temperature, cubic compressive and splitting tensile tests were carried out for different basalt fiber lengths (6 mm, 12 mm, 30 mm) and different temperatures (20 ℃, 200 ℃, 400 ℃, 600 ℃). The test results show that the compressive strength of ordinary concrete achieves the maximum strength at 200 ℃, while the hybrid fiber concrete reaches the maximum strength at 400 ℃, and then the compressive strength decreases gradually. The splitting tensile strength of ordinary concrete and fiber concrete decreases with the increase of temperature. After 600 ℃, the residual tensile strength of concrete is only 64.9%. When the basalt fiber length is 12 mm, the high temperature resistance of the hybrid fiber concrete is the strongest. At 600 ℃, the residual compressive strength and the residual splitting tensile strength are 84.8% and 68.6%, respectively.

Key words: hybrid fiber concrete, high temperature, compressive strength, splitting tensile strength