Dynamic splitting tensile behaviour and statistical scaling law of hybrid basalt-polypropylene fibre-reinforced concrete

The dynamic splitting tensile behaviour of hybrid basalt-polypropylene fibre-reinforced concrete (HBPRC) was investigated, and the reinforcing mechanism of the fibres was explored. The results indicate that the dynamic splitting tensile strength and dynamic energy dissipation capacity of HBPRC increased with strain rate. The effects of fibre type and content on the strain rate sensitivity of dynamic splitting tensile strength were consistent with that of dynamic dissipation energy. Furthermore, the dynamic splitting tensile strength of concrete was improved by adding appropriate content of basalt fibre (BF) and polypropylene fibre (PF), and the improving effect of hybrid BF and PF was the most significant. Excess fibres reduced the dynamic splitting tensile strength at low strain rates but improved it at high strain rates. The addition of fibres improved the dynamic dissipation energy and the impact resistance of concrete. With an increase in the strain rate, the pull-out lengths of BF and PF decreased gradually. When using hybrid BF and PF, the failure morphology of BF did not change considerably, although PF underwent more severe damage. Based on the weakest-link theory, a calculation model for the statistical scaling law of dynamic splitting tensile strength considering the strain rate effect was established.