Experimental Research On The Flexural Performance Of The RC Beam Strengthened By Bongding The CFRP Sheets On Lateral Side

As the retrofitting technique with fiber reinforced plastic materials is widely applied in the civil engineering practice, a lot of research and investigation on the ultimate strength of the retrofitted concrete structural members have done all over the world.At present, most of the studies on retrofitting in the negative moment area of the beam were to bond the CFRP sheets on the top side of the beam, but only few research focused on the retrofitting with CFRP side-bonding method. The first reason is the difficulty to anchor CFRP to the surface of the beam-column joints firmly, the second one is how to evaluate the effectiveness of side-bonded CFRP.In order to investigate the flexural performance of the beam retrofitted with CFRP side-bonded, this paper conducted experiments of a series of RC beams retrofitted with CFRP. The specimen consists of one control beam and 6 RC-beams strengthened with CFRP sheets. Based on the experimental results, the effect of retrofitting, the mechanism of anchorage and the flexural capacity are investigated. At last, the FEM analysis of specimen were carried out, the analytical results are consistented with experimental results well.Experimental and analytical results show that it is an effective retrofitting method to strengthen the capacity of the negative bending moment area of RC-beams with CFRP bonded on the beam sides. The anchorage with steel plate and bolts is better than the anchorage with CFRP sheets cross bonded. Comparing the three different methods to evaluate the ultimate bending capacity, the paper conclude that the method proposed by Southeast University is reasonable and credible, and it can be applied in the strengthening design.The research of this paper on retrofitting RC-beam with CFRP bonded on the beam sides is just an explore research, but it has reference value for the research hereafter and engineering practice.