Study on the bonding performance between basalt textile and concrete under freeze-thaw cycles

Basalt textile-reinforced concrete (BTRC) is an environment friendly building material attracted wide attention in civil engineering. The investigation of the durability characteristic of the BTRC specimen is an important part of guiding the design of BTRC. In this paper, the tensile and flexural performances were investigated by the pull-out test and the four-point bending test with BTRC specimens under different freeze-thaw conditions. Meanwhile, the scanning electron microscope (SEM) is employed in the micro-cracks and bonding performance analysis. The results showed that as the number of freeze-thaw cycles increased, the peak and residual bonding stress are reduced, and the same for the ultimate flexural loading. The paper presents the formulas for calculating the ultimate flexural strength of BTRC under freeze-thaw cycles, and the difference in calculating results is less than 12% of the experimental results. The SEM images are shown that as the number of freeze-thaw cycles increased, the gap between the bonding surface was widened, which also well explains the degradation of bonding performance between fiber bundles and concrete matrix. And the normalized strength degradation law satisfies the function relation well.