Minimum reinforcement ratio in TRC panels for deflection hardening flexural performance

The performance of textile reinforced concrete (TRC) was investigated with considering different parameters of fabric such as yarn type, mesh size, and yarn diameter. The fabric material was made of special Nylon yarns called “tire cord yarn”. In addition, the effects of thickness and reinforcement ratio on the flexural performance and ultimate capacity of TRC composites were studied. Sixty-five specimens were tested under four point flexural tests and minimum reinforcement ratio to achieve deflection-hardening behavior was obtained experimentally. Analytical formulation was presented for minimum reinforcement ratio and verified with experimental results. The behavior of specimens indicated that ultimate strength of the reinforced composite with the same reinforcement ratio, increases with increasing yarn Tex, and smaller mesh size improve the performance of samples with the deflection-hardening behavior. The experimental results showed that uncrack capacity of specimens raised by increasing reinforcement ratio, which could be due to shrinkage of yarns in cement media that behave as pre-stressing for concrete. In addition, results showed that the effectiveness of twisted yarns is about fifty percent lower than of the untwisted ones.