Study on Corrosion Behaviour of Basalt Fibre Reinforced Concrete under NaOH Environment

Abstract

Basalt fibre (BF) is an inorganic material with high temperature resistance, low temperature resistance, strong acid and alkali corrosion resistance and good compatibility. Addition of BF into the concrete can improve the multiple properties of concrete. The purpose of this paper is to study the durability of basalt fibre reinforced concrete (BFRC) under the alkaline environment and analyse its corrosion mechanism. To this end, in this paper, 20% sodium hydroxide (NaOH) solution was used to simulate the alkaline environment, and the control group of clear water was also set by immersing and corroding the test blocks for 90 days, 180 days and 270 days respectively. Then, the crack propagation, Na+ migration, water absorption, and compressive bearing capacity of the test blocks under different corrosion time were analysed and the failure mechanism was discussed. The results show that the addition of BF can effectively inhibit the generation and propagation of concrete cracks; in alkaline environment, the BF can effectively prevent the migration of Na+, but its effect decreases with the increase of corrosion time; compared with ordinary concrete, the BF addition in alkaline environment can improve the bearing capacity of concrete to certain degree, but insufficient or excessive addition will adversely affect the durability of concrete. Through the comprehensive analysis, when the BF content is 0.1%, the porosity, durability and compression bearing capacity of concrete are improved most obviously.