Experimental Research On Flexural Performance Of Reinforced Concrete Beams Composite Rehabilitation With Bonded Carbon Fiber Reinforced Polymer And Steel Plate

The Carbon Fiber Reinforced Plastic (CFRP) has been applied in the existing structure reinforcement as an alternative to traditional strengthening materials. Though CFRP has a lot of advantages of improving the structure's mechanical performance ,it behaves in a sort lack at some aspects such as ductility .Another strengthening material-steel plate can fetch up the CFRP's demerit .For the mutual supplementary capability of the two materials .financed cooperatively by the grant from key Science and Technology Development Project of HuBei Province and the Postdoctor Fund of National Science Foundation of China,connected with the analysis methods of modern steel reinforced concrete structure, the thesis studies the flexural performance of Reinforced Concrete beam composite rehabilitation with bonded CFRP and steel plate through the systematic study on experimental data got from this kind of beams. Systematically establishes the theoretical calculating system of flexural performance of composite rehabilitation RC beams in cooperation with the up-to-date analytical methods for reinforced concrete which suits the properties of the composite reinforced beams.In the paper, fifteen reinforced concrete test specimens were used to study the ultimate bond load .The effect of concrete strength, reinforcement ratio, the dosage of CFRP and steel plate were taken into consideration. Experimental results indicate that: the CFRP and steel plate composite rehabilitation methods can effectively improving the load capacity of RC beams, restricting the development of exsiting crack, enhancing section stiffness; As to the ductility, the composite rehabilitation RC beam's is lower than that of RC beam, but it is close to the CFRP rehabilitation reinforced concrete beam's,and it can satisfy the requirement of section ductility commonly;In addition,.by using U style steel plate hoop anchorage system ,sudden debonding failure can be avoided.Based on the mechanical performance of composite rehabilitation RC beams, the method for calculating the normal section flexural load-bearing capacity is proposed, which can meet Chinese engineering requirements. Analyzing the variational process of the stiffness and ductility performance, and establishing the formulae accordingly, the caculating value can match the test one well. According the debonding phenomena of the strengthening layer, the failure mechanism of the composite rehabilitation is probed. The shortest bolt length of CFRP in composite rehabilitation is suggested as well as the computation formula for the deformation of the beams.