Shear strengthening of reinforced concrete T-beams under cyclic loading with TRM or FRP jackets

The paper presents a systematic investigation on the effectiveness of U-shaped textile-reinforced mortar (TRM) jackets as shear strengthening materials of reinforced concrete T-beams, by examining a number of parameters not studied before: cyclic loading; fixed support conditions; different types of textiles; different numbers of layers; anchors; the relative performance of TRM versus equivalent FRP systems; and different displacement amplitudes of the loading cycles. For beams without anchors it is concluded that the effectiveness of TRM increases non-proportionally with the number of layers and that, for the same total volume fraction of fibers in the jacket, one layer of textile is more effective than two. For beams with anchored TRM jackets it is concluded that the effectiveness of the strengthening system is quite high, as is the effectiveness of an anchored FRP system. The results are used to derive simple analytical models for the effective strain in anchored or non-anchored TRM jackets.