Research On Mechanical Performance Of Partial Interaction GFRP-concrete Beam

Conventional bridges which use steel and concrete in sea area and frost area have serious corrosion problems,the cost of maintain and repairing bridge increases yearly.Fiber reinforced polymer(FRP)can effectively solve these problems due to their anticorrosion,high strength-low density etc.and glass fiber reinforced polymer(GFRP)profile concrete composite beam structure is one of the most economical system use in the sever area.Shear connection is the key role to insure GFRP and concrete act compositely.There are three types of shear connection way and formula introduced in <Technical code for infrastructure application of FRP composites>,but not include the steel bolt connection and ignore the slip between the GFRP and concrete.However the elasticity modulus of GFRP is extremely lower than steel and the steel bolts are not welded in GFRP profile,composite action between GFRP and concrete is not strong enough.Hence there is a greater than ever need for studies of the mechanical property of GFRP concrete composite beam with steel bolt connection.The specific research content is as follows:1.Summarizing and inducing the private achievements: Theoretical calculation of steel bolt connection and mechanical property of partial interaction composite beam has been collected.2.Parameter analysis of push-out test: Push-out test is one of the most effective way to know the steel bolt connection.Using ABAQUS to simulate the push-out test and analyze the results.And then using the vast array of steel bolt diameter,embedded length,thickness of concrete,thickness of FRP flange etc.to analyze these parameters effect on push-out results.Finally,making a comparison between the theoretical value and simulating results to submit amendments.3.Composite beam analysis: Simulating the GFRP-concrete composite beam with steel bolt connection to observe the effect of connection distribution on composite beam,and making a comparison between the theoretical values and simulating results to submit amendments.The results shows that GFRP-concrete push out tests have three types of failure mode,concrete compression failure,concrete tensile failure and steel bolt cut.The reason why the concrete tensile failure could happen is that elasticity modulus of GFRP is too low to constraint the rotary movement of steel bolt and concrete sustain tension.Hence the reinforcements and the thickness of concrete extremely affect the results of simulating.The results of GFRP concrete composite beam simulating shows that spacing between two steel bolts has great influence to the rigidity of composite beam.But the slip has less influence on composite flexural capacity through making a compression between the FEA results and theoretical value.In fact,practice engineering not allow the big slip,and theoretical method fit well with small slip composite beam so these theoretical methods to calculate the mechanical property of GFRP-concrete composite beam satisfy the engineering demand.