Experimental Investigation of the Behaviour of Concrete Beams Reinforced by GFRP Bars and Strengthened by CFRP and Steel Sheets Under Pure Bending Moment

One of the conventional retrofitting methods for reinforced concrete beams is flexural strengthening of beams with CFRP materials. In this study, a full scale reinforced concrete beam is constructed and evaluated under four-point flexural test. Afterward, a same beam is retrofitted in flexural region by monolayer of CFRP. These experimental tests are carried out to be the basis of verification for numerical specimens. The first, an unreinforced beam is subjected to four-point loading in the laboratory. Then, to strengthen the beam in the flexural zone, three similar beams is reinforced and reinforced in the flexural zone using a layer of CFRP sheet, a layer of steel sheet and GFRP rebar. The reinforcement of the beams is done in the middle range, and after loading, bending failure occurred in all the beams. The results show that the reinforced concrete beam has much impact on carrying capacity, but would crash out of the range of the bending beam will be soon. The results also show that by performing local reinforcement in the flexural zone, in some beams, the first cracks occur outside the flexural range, while the final flexural failure occurs in the middle range of the beam.