Experimental Study On Long-term Performance Of Reinforced Section Reinforcement

At present,the research on the method of bridge reinforcement mainly focuses on new materials and new technologies,and there is no great deal of research on the optimization and improvement of traditional cross-section reinforcement method.And a large number of cross-section reinforcement method used in reinforced concrete bridge,which also exists a lot of urgent need to solve the problem.According to the research status domestically and abroad,the long-term performance of the section reinforcement method is not perfect.Therefore,in order to increase the long-term performance of the section reinforcement method,the fatigue performance of the reinforced beam and the bonding surface of the old and the new concrete Knot mode under the fatigue load of the two ways to study the failure.Specific research is as follows:(1)This paper summarizes the microscopic model and fracture model of the old and new concrete viscous sections with increasing cross-section reinforcement method,and the evaluation method of the roughness of the bonded cross-section.Based on the existing old and new concrete bond surface fracture model,the design of different roughness old and new concrete The corresponding failure model is proposed and verified by experiment.(2)The five kinds of reinforced concrete beams were tested,in which the two beams were subjected to the static load test,and the ultimate bearing capacity obtained by the static test was used for the fatigue test of the other three beams(fatigue test load And the ultimate bearing capacity of 0.2 to 0.8 times is observed.The failure process of the fatigue test beam is observed.Finally,the fatigue life of the steel sheet of the three fatigue tests is obtained.The results show that the life of the new and old concrete bonded face beams is higher.(3)The two kinds of reinforced beams have different bonding methods in the fatigue test.One for "floating slurry" treatment,the other one for "groove" treatment,in the process of increasing the number of fatigue cycle load,compared the two kinds of treatment under the fatigue load difference.(4)Using Midas FEA to model the test beams,and to increase the cross-sectionreinforcement beam "floating slurry" layer,"groove" bonding surface to be considered,under the static force of the situation,the use of static calculation The results show that the stress of the steel bar is the most unfavorable position,and then the fatigue calculation of the steel bar is carried out separately.The fatigue life of the steel bar is obtained and compared with the experimental results,which can be used to verify the fatigue calculation method.(5)Using the data of static loading under the number of cycles of fatigue test,the stiffness of each fatigue load cycle is calculated.Through the simulation of stiffness degradation,curve fitting is carried out by Matlab and,the results of this paper can be used to increase the cross-section reinforcement design and construction reference.