Orthogonal experiment on mechanical properties of basalt fiber-carbon fiber/slag concrete

The slump, cube compressive strength and splitting tensile strength tests of 16 groups of basalt fiber-carbon fiber(BF-CF)/slag concrete and 1 group of C40 reference concrete were conducted by orthogonal experimental method. The effects of BF, CF and slag on the mechanical properties of BF-CF/slag concrete were investigated. The test results show that the cube compressive strength and splitting tensile strength of BF-CF/slag concrete are higher than the cube compressive strength and splitting tensile strength of C40 reference concrete, i.e., the maximum increase of cube compressive strength is 21.0%, and the maximum increase of splitting tensile strength is 35.3%. The addition of BF and CF can reduce the slump of concrete, and BF can reduce the slump more significantly. The maximum drop of BF to the slump is 67.1%. The mass fraction of slag replacing for sand is a significant factor affecting the cube compressive strength of BF-CF/slag concrete. With the increase of mass fraction of slag replacing for sand, the cube compressive strength first increases and then decreases, and the maximum increase of slag to the cube compressive strength is 7.6%. BF is a significant factor affecting the tensile strength of BF-CF/slag concrete, and the tensile strength increases with the increase of the volume fraction of BF. The maximum increase of BF to the tensile strength is 12.0%, and the increase of CF to the tensile strength is not obvious. The results of the orthogonal experiment were regressed, and the prediction models of the cube compressive strength and splitting tensile strength of the BF-CF/slag concrete were obtained, and the accuracy of model is high. © 2020, Editorial Office of Acta Materiae Compositae Sinica. All right reserved.