Textile-reinforced mortar versus fiber-reinforced polymer confinement in reinforced concrete columns

The effectiveness of textile-reinforced mortar (TRM) jackets as a means of confining reinforced concrete (RC) columns with limited capacity due to buckling of the longitudinal bars is experimentally investigated in this study. Comparisons with fiber-reinforced polymer (FRP) jackets of equal stiffness and strength allow for the evaluation of the effectiveness of TRM versus FRP. Tests were carried out both on short prisms under concentric compression and on nearly full-scale, nonseismically detailed, RC columns subjected to cyclic uniaxial flexure under constant axial load. The compression tests on 15 RC prisms show that TRM jackets provide a substantial gain in compressive strength and deformation capacity by delaying buckling of the longitudinal bars; this gain increases with the volumetric ratio of the jacket. Compared with their FRP counter-parts, TRM jackets used in this study are slightly less effective in terms of increasing strength and deformation capacity by approximately 10%. Tests on nearly full-scale columns under cyclic uniaxial flexure show that TRM jacketing is very effective (and equally to its FRP counterpart) as a means of increasing the cyclic deformation capacity and the energy dissipation of old-lype RC columns with poor detailing by delaying bar buckling. The test results presented in this study indicate that TRM jacketing is an extremely promising solution for the confinement of RC columns, including poorly detailed ones in seismic regions.