Flexural Durability and Chloride Diffusion Equation of TRC-Strengthened Beams under a Chloride Environment

Abstract

In this study, the chloride ion diffusion and structural performance of beams reinforced with textile-reinforced concrete (TRC) were evaluated. The parameters investigated were chloride concentration, sustained load and number of textile layers. The results demonstrate that the content and diffusion coefficient of chloride increased with increasing chloride concentration. Higher chloride concentrations accelerated the crack propagation and deflection changes and caused the reduction of the load-carrying capacity of the beams. The sustained load promoted the chloride transport of the TRC, increasing the chloride ion content and diffusion coefficient and causing substantial damage to the microstructure of the TRC. In addition, the performance (such as cracking resistance, deflection and flexural capacity) of beams with a large sustained load ratio decreased to a less extent than did the performance of the unloaded beams. The content and diffusion coefficient of chloride in the unstrengthened beams were obviously larger than those in the strengthened beams, but increasing the textile layers number had little influence on these factors. In addition, for the unstrengthened beams, the cracks and deflections developed rapidly, and the load decreased greatly, especially the cracking load. Finally, in accordance with Fick’s second law of diffusion, a chloride diffusion equation in TRC layers under new boundary conditions was proposed.