The aim of this thesis is to test a new method in the prevention and treatment of beams failed in torsion. It details the decreased strength of beams incorrectly reinforced for torsion with transverse reinforcement cogged at an angle of 90o. The method used to treat these beams is an application of the MBrace carbon-fibre reinforcing system.
Four beams are subjected to pure torsion in a specially designed apparatus, three of the beams are incorrectly reinforced for torsion with transverse reinforcement at an angle of 90o, and the other is correctly reinforced at an angle of 135o. Two of the incorrectly reinforced beams are wrapped in the FRP. One beam was wrapped before it was loaded. The other beam aimed to test the remedial properties of the FRP in torsion; it was loaded until initial failure in when cracks started to occur, then unloaded and wrapped in FRP and re-tested until ultimate failure.
This thesis contains a literature review, an outline of experimentation presented with a discussion of results and conclusion with recommendations.
The results of the experimentation in this thesis confirm that the beams with transverse reinforcement cogged at 90o have a reduced stiffness compared with those correctly hooked at 135o. The results also establish that the beams externally reinforced with FRP have substantially more torsional resistance than those not reinforced.