Experimental Research On GFRP-concrete-steel Composite Bridge Decks And Shear Connections

Fiber Reinforced Polymer(FRP)has been widely applied in reinforcement of civil construction structure due to their high strength-to-weight ratio,corriosion resistance and good fatigue resistance.The use of FRP has gradually become a hot research.Quite a few scholars have carried on researches on the form and perforcemance of FRP-concrete composite structure.GFRP-concrete-steel composite beam is a kind of structure that GFRP-concrete composite bridge deck is connected to steel girder with shear connections.This kind of structure can take full advantage of properties of three materials and has vast potential for future development.To build the GFRP-concrete-steel composite structure,this paper mainly concentrated on the shear property of GFRP-concrete-steel shear connections and mechanical behavior of GFRP-concrete composite bridge decks.The research work mainlu included the following four parts:(1)Transverse tests of GFRP-concrete composite beidge decks.7 GFRP-concrete composite decks and 1 steel-concrete decks were tested to investigate the influencing factors of bonding effect of GFRP-concrete interface.Studies showed that the effect of gravel coverage on the bonding effect of GFRP-concrete interface and the working performance of composite deck is the most obvious.On the premise that the bonding effect can be ensured,the ultimate bearing capacity and failure mode of composite decks is the same as steel-concrete decks,but the former stiffness is less than the latter.(2)Finite element analysis of GFRP-concrete composite beidge decks.An overall process analysis of GFRP-concrete composite decks was simulated by ABAQUS software.The results of numerical modeling showed that the finite element analysis was in good agreement with test results.Based on the simulation,some parameters including the shear properties of interface,concrete slab thickness and concrete strength were taken into consideration to investigate the effects of those parameters on the mechanical behavior of composite decks.(3)Push-out tests of GFRP-concrete-steel shear connctors.6 GFRP-concrete-steel specimens and 1 steel-concrete specimen were tested to investigate factors influencing the stiffness.Studies showed that the diameter has the largest impact on the bearing capacity and stiffness of GFRP-concrete-steel composite structure.After the interface between GFRP and steel was glued,the epoxy and studs beared the shear together.This kind of interface changed power transmission of the structure.The load-slip curve of GFRP-concrete-steel specimens is similar to steel-concrete specimens.(4)Finite element analysis of GFRP-concrete-steel push-out specimens.An overall process analysis of GFRP-concrete-steel shear connections was simulated by ABAQUS software.The results of numerical modeling showed that the finite element analysis was in good agreement with test results.Based on the simulation,some parameters including the stud diameter,concrete strength,yield strength of sutd,GFRP plate thickness and opening diameter were taken into consideration to investigate the effects of those parameters on the shear behavior of stud connections.The shear-slip curve formula of GFRP-concrete-steel stud connections was given by parameter fitting method.