Research on chloride diffusion and flexural behavior of beams strengthened with TRC subjected to dry-wet cycles

Abstract

This paper presents an experimental study on the flexural durability of beams strengthened with TRC subjected to dry-wet cycles. The effects of dry-wet cycles (180, 210, 240, 270 and 330) and the short-cut fiber contents (0, 0.2%, 0.5% and 1%) on chloride transport and flexural behavior were investigated. The results showed that with the increase of dry-wet cycles, the chloride ion content in the TRC increased, while the diffusion coefficient decreased, the micro-structure of the TRC matrix was obviously damaged after 330 cycles. A certain amount of short-cut fibers was beneficial to improve the chloride transport resistance of the TRC matrix. The effect of increasing dry-wet cycles on the overall mechanical properties of the strengthened beams fluctuated when there were few dry-wet cycles. However, the mechanical properties of the strengthened beams significantly diminished after 330 cycles. The mechanical properties of the strengthened beams were enhanced with the increase of short-cut fiber content, and the promotion effect was obvious as it reached 1%. Finally, the ultimate bearing capacity formula of TRC-strengthened beams subjected to dry-wet cycles was modified based on the test results.