Effects of basalt fibre and rubber particles on the mechanical properties and impact resistance of concrete

Abstract

The application of waste rubber particles and basalt fibre (BF) in concrete can not only improve the performance of the resulting concrete but also alleviate the environmental pressures related to waste tire disposal. In this study, the impacts of rubber particles and BF on the mechanical and impact performance of concrete are experimentally investigated. Additionally, the macroscopic test phenomenon is explained based on the appearance of the microstructure. The results show that for basalt fibre-reinforced concrete (BFC), when the BF content increases from 0 to 0.4 %, the cube compressive strength and elastic modulus decrease from 71.5 MPa to 62.5 MPa and 44.5 GPa to 41.0 GPa, respectively, while the bending strength increases from 5.9 MPa to 6.6 MPa and then decreases to 6.3 MPa. A BF content of 0.3 % is selected to prepare basalt fibre-reinforced rubber concrete (BFRC). As the rubber particle content of BFRC increases from 0 to 20 %, the cube compressive strength, elastic modulus and bending strength decrease from 64.3 MPa to 51.5 MPa, 41.9 GPa to 33.5 GPa and 6.6 MPa to 5.9 MPa, respectively. However, the reduction rate of the mechanical properties of BFRC is approximately half that of fibre-free rubber concrete at the same rubber content. The shapes of the stressstrain curves of the BFC and normal concrete (NC) are similar, whereas the descending stage of the stressstrain curve of the BFRC is obviously gentler, and the whole BFRC stressstrain curve is much fuller, reflecting typical ductile failure. Both the BF and rubber particles contribute to impact performance improvement, but the effect of the rubber particles is much greater than that of the BF. Compared with that of the NC, the incorporation of 0.3 % BF increases the initial crack impact energy (W1) and final crack impact energy (W2) by 71 % and 79 %, respectively, but when 20 % rubber particles are additionally added, the increase rates of W1 and W2 reach 668 % and 686 %, respectively. The impact life evolutions of BFC and BFRC can be described effectively by a two-parameter Weibull distribution function.