Experimental study on the mechanical properties and impermeability of basalt-PVA hybrid fibre reinforced concrete

Numerous studies have indicated that the incorporation of chopped fibres can significantly improve the mechanical properties and durability of concrete. To further explore the effect of chopped basalt fibres, PVA fibres and their hybrid fibres on the improvement of concrete mechanics and impermeability, mechanical property and impermeability tests of chopped basalt fibres/PVA fibres of different lengths and hybrid ratios mixed with concrete of disparate benchmark strengths were carried out. By comparing the characteristic values of each group and their variation rules, the optimal length and hybrid ratio of the fibres were determined. The results show that the enhancement effect of chopped basalt fibres of different lengths on the mechanical and impermeability properties of concrete is different, showing a trend of first increasing and then decreasing. The enhancement effect of chopped basalt fibres on the mechanical and impermeability performance of concrete with different benchmark strengths is better than that of PVA fibres. Compared with those of the C30 plain concrete, the mechanical and impermeability properties of the chopped basalt-PVA hybrid fibre concrete significantly improve to varying degrees. When the proportion of chopped basalt fibres is greater than or equal to the proportion of PVA fibres, a positive hybrid effect on the mechanical and impermeability performance of concrete with the same benchmark strength occurs. With increasing benchmark strength, the enhancement effect of the two types of fibres on the mechanics and impermeability of the concrete decreases. The attenuation range of PVA fibres is greater than that of chopped basalt fibres, and even a reduction in the mechanical and impermeability properties of concrete occurs. This results in the enhancement effect of chopped basalt-PVA hybrid fibres on concrete mechanics as well as a significant decrease in the impermeability. The improvement rates of the compressive performance and impermeability of concrete by a single or a hybrid of the two fibres are highly similar, and the enhancement effect of the fibre compressive performance is significantly greater than that of the impermeability. • The optimum fibre length and hybrid ratio to enhance the performance of concrete were determined respectively. • The pattern of fiber enhancement of concrete properties with different benchmark strengths was investigated. • The enhancement of compressive and impermeability properties of concrete by fibres were compared.