Local Strengthening of Reinforced Concrete Frames Using Textile Reinforced Mortar Jackets under Gravity and Cyclic Loadings

Abstract

This paper investigates the effectiveness of local strengthening using textile reinforced mortar (TRM) jackets on the global response of reinforced concrete (RC) frames under gravity and lateral cyclic loadings. Finite element analysis (FEA) was employed to develop and validate an RC bare frame model against an experimental study in the literature. Consequently, four TRM strengthening configurations were applied considering the column’s confinement and strengthening of joints and beams. With the aim to attain a ductile behavior of the frame, the selection of each configuration was based on the predicted failure of the preceding strengthening arrangement. A parametric study was performed to investigate the effect of the number of layers, length of TRM jackets, textile orientation, and distributed load values. Finally, the FEA models were compared with traditionally and noninteracting masonry infilled frames from the literature. By evaluating the local retrofitting influence on the global response of the frames, the strength and stiffness enhancements were marginal as compared to the control model. Local measures were more effective in the frame’s post-peak response, hence, enhancing the ductility of RC frames. The TRM application to the beam-column joints resulted in substantially higher energy dissipation as compared to the model with no joint upgrading. When comparing the TRM local strengthening method to the global technique using infilled walls, the TRM retrofitted models showed similar energy dissipation to that of noninteracting masonry infilled specimen and lower values than those of the traditionally infilled frame.