Effects of Hybrid Basalt-Brucite Fibers in the Microstructure of Low Heat Cement Concrete

In this paper, the mechanical properties and microstructure of hybrid basalt-brucite fibers reinforced low heat cement concrete were investigated, including compressive strength, splitting tensile strength, hydration products, microstructure, and pore. The results showed that the composite effect of hybrid fibers could effectively affect the failure mode of specimens, and improve the mechanical properties of low heat cement concrete that under optimal dosage conditions, it reached the maximum value, which were 40.2% for compressive strength and 70.6% for splitting tensile strength higher than the benchmark group. Based on microscopic techniques, hybrid fibers was found that it had a good bonding effect with the mortar. The failure modes of hybrid fibers in mortar included pull-out, tensile failure, and torsional failure. Meanwhile, mineral fibers could effectively promote hydration reaction, enhance the interface transition zone between fibers and concrete, and improve the compactness of concrete by compensating for small pores in concrete. Based on the theory of composite materials, the reinforcement mechanism of hybrid fibers on low heat cement concrete was elucidated.