Papers by Keyword: Post-Poured Layer

Abstract: The flexural behavior of reinforced concrete (RC) members strengthened with postpoured Ultra High Toughness Cementitious Composites (UHTCC) was investigated in this paper. The flexural behavior, failure mode and crack propagation during loading process of composite specimens were studied, and their structural behavior was also compared to that of original members. The experimental results showed that post-poured UHTCC materials enhanced flexural bearing capacity and toughness of existing concrete members. And introducing UHTCC material into strengthening enabled the composite specimens sustain the loading at a larger deflection without failure. It also revealed that post-poured UHTCC layer dispersed larger cracks in upper concrete into multiple tightly-spaced fine cracks, which prolonged the appearance of harm surface cracks and improved the durability of existing structures.

Abstract: For studying the effectiveness of externally pouring Ultra High Toughness Cementitious Composites (UHTCC) in improving the flexural behaviors of existing reinforced concrete beams, four-point bending tests were conducted up to failure on seven RC beams and strengthening beams. The flexural strength, failure mode and crack propagation of composite beams were investigated. The results showed that pouring UHTCC on the bending surface of reinforced concrete beams properly to improve the ductility and load capacity of composite beams. It was also found that UHTCC layer restricted the development of cracks in upper concrete and dispersed them into multiple fine cracks effectively. Compared with post-poured concrete, UHTCC was more suitable for working together with reinforcement. The load-deflection plots obtained from three-dimensional finite-element models (FEMs) analyses were compared with those obtained from the experimental results, which showed close correlation.