Research on the Uniaxial Compression Performance of Basalt Fiber-reinforced Recycled Aggregate Concrete

Abstract

This study improves the mechanical properties of recycled concrete by adding basalt fibers, thereby promoting the widespread application of recycled concrete in engineering. The research results indicate that basalt fibers can increase the cube compressive strength of recycled concrete, the optimal dosage of basalt fibers is 0.3 %, and an increase in compressive strength can increase the compressive strength by 7.96 %. The presence of basalt fibers can form a three-dimensional disordered distribution support system inside recycled concrete, limiting the generation and propagation of microcracks under uniaxial compression, maintaining a certain degree of integrity during the failure process of recycled concrete, and making the descending section of the stress‒strain curve relatively stable. With increasing basalt fiber content, the peak stress of recycled concrete under uniaxial compression tends to first increase but then decrease, whereas the peak strain of recycled concrete under uniaxial compression tends to increase. A calculation model for the compressive strength, peak stress, and peak strain of basalt fiber‒reinforced recycled concrete is constructed. The strengthening mechanism of basalt fibers on the uniaxial compression performance of recycled concrete is discussed.