PRELIMINARY INVESTIGATION ON THE DURABILITY OF FRP

The use of reinforced glulam beams as bridge girders raises several concerns. Bridges see many repetitions of high loads throughout their life span, which may generate fatigue related issues in either the wood or the FRP. Furthermore, bridge girders are subjected to the atmospheric variations, under which the wood will exhibit significant dimensional changes whereas the FRP will undergo only small dimensional changes. Since these materials are bonded together, significant stresses may develop near the material interface. In this study, four 1 6 4 beams reinforced with glass FRP were fatigued at design loads. Two of the beams had full reinforcement and two of the beams had partial length reinforcement. Two reinforcement types were used: wet-preg glass with a MOE in tension of 5750 ksi and pultruded glass with a MOE in tension of 63 1 1 ksi. Of the beams tested one was loaded to its design moment and 72 % of its design shear and the other three were loaded to both their design moment and design shear simultaneously. Three of the beams exhibited shear failures and the beam with partial length pultruded reinforcement had an FRP delamination failure