TRM verses FRP in torsional strengthening of RC beams

This paper aims to assess the effectiveness of TRM and FRP in torsional strengthening of RC. The examined variables were: the type of bonding agent (epoxy resin versus cement mortar), the material of the textile fibers (dry carbon and coated glass), the strengthening configurations (partially & fully) and the strengthening orientation (45°&90°). Thirteen large-scale beams were casted, strengthened, and tested monotonically up to failure. One used as a control, six specimens were strengthened with TRM and the rest six specimen were retrofitted with FRP. It was mainly found that: (a) the effectiveness of TRM composites in increasing the torsional capacity was approximately similar to that of FRP composites; (b) the Carbon fiber textile was more effective than glass fiber textile in enhancing the torsion capacity in FRP strengthened specimens. In contrast, the coated glass fiber textile performed better than the carbon fiber textile in the TRM reinforced specimens; (c) the 45° strengthening orientation in the TRM was less effective than the 90° strengthening orientation due to the premature debonding at the ends. This was not the case in the FRP where the 45° strengthening orientation showed higher torsional strength than that of 90°.