Study On The Mechanical Properties Of Reinforced Concrete Continuous Beam Based On ICCP-SS Double Repair Technology

In view of the coastal environment of reinforced concrete structure durability problems caused by steel corrosion,two effective solutions that are impressed current cathodic protection technique(ICCP)and structural strengthening method(SS)have proposed by researchers.However,ICCP and SS technique have some limitations: ICCP can inhibit steel corrosion,but unable to restore previously reduced mechanical strength due to the corrosion of steel;although SS can recover or improve the bearing capacity of the structure,it cannot prevent the corrosion of the steel.Therefore,the newly method denominated by ICCP-SS double repair technique that is the combination of ICCP technique and SS method is proposed.It achieves dual function of steel protection and structure reinforcement,which adopts CFRP mesh as the anode material and structure reinforcement material and uses cementitious material as adhesive material.However,in the study of structural behavior of RC continuous beams,there is no precedent of using the ICCP-SS double repair technique.Relative to the simply supported beam,continuous beam is more common in civil engineering.Therefore,the mechanical properties of RC continuous beam based on ICCP-SS double repair technique have been studied.In this paper,nine RC continuous beams have been tested.The experiment mainly studied the effectiveness,ultimate bearing capacity,crack situation and internal force redistribution process of continuous beam under different position protection of ICCP-SS.According to the experimental results and theoretical analysis,it can be seen that ICCP-SS double repair technique can not only inhibit the corrosion of steel reinforcement in continuous beam,but also improve the structural bearing capacity.The protection of different positions has different effect on reinforcement protection and bearing capacity.ICCP-SS double repair technique can not only improve the yield load of the repair section,but also indirectly increase the yield load of the unrepaired section due to the characteristics of the continuous beam plastic internal force redistribution.ICCP-SS double repair technique can effectively limit crack width and reduce the crack spacing.ICCP-SS double repair technique can affect the moment distribution of continuous beam,and it is related to the protection position.Neutral axis depth approach which is adopted by the current code is not suitable for continuous beam repaired by ICCP-SS.Finally,on the basis of reasonable assumption,we improve the original "virtual beam method",and puts forward the calculation formula of ultimate bearing capacity of sea sand concrete continuous beam using ICCP-SS.