Shear strengthening of concrete bridge decks using FRP bar

The shear capacity of existing concrete bridge beams is often inadequate and unable to meet current code requirements. This paper deals with a new type of shear strengthening for existing concrete bridges. It is proposed that vertical FRP bars be inserted into pre-drilled holes and fastened in place using epoxy resin. This method has the advantage that only the soffit of the concrete bridge beam (or slab) is required for access, allowing the top surface to remain undamaged during strengthening. This could allow the bridge to be used during strengthening works, with traffic relatively unhindered by work being carried out below. Ten laboratory tests are presented here to demonstrate the system, and comparisons are made against current code predictions for the strength of such concrete beams with and without transverse reinforcement. The results of this work show that the proposed strengthening scheme is effective and provides significant improvement in the shear-carrying load capacity.