Cyclic behavioral characteristics of RC beams strengthened by U-wrapped TRM jacket with anchorage details

Abstract

In this study, we investigated the seismic performance of reinforced concrete (RC) beams strengthened by a Uwrapped textile-reinforced mortar (TRM) jacket with and without incorporating anchorage details. Ten full-scale single-curvature RC beams were fabricated and tested under cyclic loading. The main test parameters included longitudinal reinforcement ratio, textile reinforcement ratio adopted in the TRM composite, and anchorage details applied to the U-wrapped TRM jacket. In the present study, a near-surface mounted (NSM) anchorage method with steel rebars was newly proposed to enhance the effectiveness of the TRM jacket. The experimental results indicated that the NSM anchorage detail was beneficial in preventing the debonding of the TRM jacket from the concrete substrates under cyclic loading conditions. Consequently, the specimens retrofitted with anchored jackets showed an improvement in terms of load-carrying and deformation capacity, stiffness degradation, and energy dissipation capacity compared to the non-anchored test specimens. In addition, an analytical model was proposed to predict the inelastic deformation capacity of RC beams strengthened with a U-wrapped TRM jacket based on the failure mechanism of the concrete compression zone after flexural yielding, and its prediction showed reasonable agreement with the experimental results.