Experimental study on the resistance of basalt fibre-reinforced concrete to chloride penetration

Abstract

This paper presents the simultaneous effect of basalt fibre (BF) and mineral admixtures (fly ash and silica fume) on the resistance of concrete to chloride penetration at different curing ages. Fifteen mixtures with five BF volume contents and three types of cementitious materials were fabricated and cured for 28 or 56 days. The apparent density, compressive strength, charge passed and chloride diffusion coefficient were tested and analysed. The results show that the maximum compressive strength of basalt fibre-reinforced concrete (BFRC) is obtained when the BF content is 0.15%. The addition of BF decreases the chloride resistance of concrete, and the higher the BF volume is, the lower the resistance. Incorporating mineral admixtures and increasing the curing age not only improve the resistance of BFRC to chloride penetration but also mitigate the adverse effect caused by BF, especially when fly ash and silica fume are simultaneously used. Moreover, the microstructure of concrete was explored to elucidate the macro-properties of BFRC in terms of its fibre bonding performance, fibre-matrix interfacial transition zone (fibre-ITZ) characteristics, pore size distribution and porosity.