EXPERIMENTAL STUDY OF THE CHLORIDE-ION PERMEABILITY OF BAMBOO-FIBER-REINFORCED CONCRETE

This study investigated the chloride-ion permeability of C30 concrete by adding bamboo fibers with different treatments (untreated, treated with calcium hydroxide solution and treated with sodium hydroxide solution) and different dosages. Three testing methods, namely the electric-flux method, AC test method and the RCM method, were used to characterize the concrete. Parameters such as electric-flux value, AC resistivity and chloride-ion diffusion coefficient were obtained. Results showed that the surface impurities of the bamboo fibers treated with calcium hydroxide solution were removed and the thermal stability of the bamboo fibers was improved, which can effectively enhance the chloride-ion permeability of concrete. Compared to untreated bamboo fibers, the improvement rate was between 14 % and 17 %. Sodium hydroxide is a strong alkaline solution, which can easily disrupt the structure of bamboo fibers and reduce the resistance of concrete to chloride-ion penetration. The best chloride-ion permeability was achieved when the bamboo fiber content reached 2 %. The electric-flux method, AC test method, and the RCM method were mutually validated with good correlation. It is recommended to choose a suitable and simple method for testing. Bamboo-fiber concrete lays a solid foundation for the future transformation of the civil-engineering industry.