Research On The Mixing Reinforced Technology Used To Strengthen Maowan Bridge In Zhongshan City

Zhongshan Maowan bridge has five continuous reinforced concrete box girders,and its combination models for(16+24+30 +24+16)m,bridge span is 114.63 m,opened at the end of 1994.Inspection by the relevant institutions,four types of bridge,which was rated capacity and cannot meet the requirement of the design load level,strengthen the maintenance needs to be.At present,the reinforced concrete bridge,the most commonly used two methods of passive reinforcement is pasting steel plate and paste fiber reinforced composite materials(FRP)reinforcement method.Pasting steel plate reinforced method can effectively improve the stiffness and bearing capacity of the structure,but steel heavy,easy to corrosion,poor durability,maintenance is difficult.To strengthen the construction of existing concrete structures can cause secondary damage.Paste FRP reinforcement method has the advantage of light deadweight,high strength,corrosion resistance,the advantages of convenient construction,and construction will not cause secondary damage to the original concrete structure,but the disadvantage is that structural stiffness increase is limited.In order to comprehensively play the advantages of two kinds of strengthening methods,this paper combines the above two kinds of strengthening methods effectively,puts forward a new method of FRP-steel mixed reinforcement and technologies,and in zhongshan Maowan bridge has been successfully used in the reinforcement engineering.In this paper,the main research contents and conclusions are as follows:1)FRP-steel mixed reinforcement methods and techniques of experimental verification.The proposed hybrid reinforcement method is to steel plates and carbon fiber sheet(CFL)for parallel interval reinforcement.In order to verify the reinforcement effect of the method,the design of reinforced concrete plate specimen,the plate for paste,paste CFLS and CFLS-mixed reinforcement of three methods for reinforcement,such as the contrast experiments.The experimental results show that CFLS-steel mixed reinforcement methods and techniques to be effective.2)The finite element analysis.Using finite element software Midas and Dr.Bridges,the zhongshan Maowan bridge structure analyzed before and after reinforcement.Calculation results show that the CFL-steel mixed reinforcement technique can improve the bearing capacity and stiffness of the structure of the bridge and meet the requirements of restoring the bridge function of the original design.3)The engineering application.Before on zhongshan Maowan bridge reinforcement on the static load test.Then make reinforcement design scheme,and according to the design in each of the bridge across the bottom of the box girder,and the use of steel plate and CFL stripe,parallel to the axis direction along the bridge,interval to the implementation of the reinforcement construction.On Maowan bridge reinforcement project is completed and the static load test experiment.Static load experiment results show that the proposed CFLS-steel mixed reinforcement technology,can improve the bearing capacity of the bridge structure,and can improve the stiffness of the structure.Furthermore,this method can reduce the weight of the reinforcement materials,shorten the construction period,compared with the traditional single paste reinforcement technology,has obvious advantages.