A Simplified Design Approach for Predicting the Flexural Behavior of TRM-Strengthened RC Beams under Cyclic Loads

This paper proposes a simplified design approach to predict the flexural behavior of reinforced concrete (RC) beams strengthened by high-performance textile reinforced mortar (TRM) under cyclic loads. Based on the experimental results, the effect of main factors on the beams as well as the effectiveness and reliability of TRM strengthening layer under cyclic loads were examined as per ACI 437 method. The reinforcement ratio of the original RC beams, the textile reinforcement ratio of TRM layer, and the interface bond between the original beam and TRM layer, all have significant influence on the flexural behavior and failure modes of TRM-strengthened beams. The simplified models based on the fib model and the Architectural Institute of Japan (AIJ) standard were suggested to predict the flexural capacity of the strengthened beams. These were also used to evaluate the flexural curve of the beams while employing simplified calculation models of the deflection capacities of the RC beams. The results verified that the simplified capacity curve model presented good accuracy to evaluate the TRM-strengthened RC beams.