Experimental Study On Mechanical Behavior Of FRP Plateconcrete Composite Interface Under Seawater Immersion And Load Coupling

Conventional reinforced concrete structures and steel structures are prone to steel corrosion in harsh environments such as the ocean,leading to premature failure of the structure.FRP materials have significant advantages such as corrosion resistance,fatigue resistance,light weight and high strength,and can be used as structural materials instead of steel.The properly designed FRP profile-concrete composite structure can give full play to the advantages of lightweight and high strength of FRP materials and high compressive strength of concrete.FRP profile-concrete composite structure has the potential of high durability and high fatigue resistance,and it is a structural form with great application potential.Due to the high tensile properties of FRP materials and the high compressive properties of concrete,the composite interface is the easiest to break first in FRP profile-concrete composite structures,ensuring the reliability and durability of the composite interface is the premise and basis for the development of this composite structure.It can be seen that it is very necessary to study the mechanical properties and degradation mechanism of the FRP-concrete composite interface in the marine environment.This paper has carried out research work on the durability of FRPconcrete composite interface in marine environment.The main work contents are as follows:(1)The durability of four kinds of FRP plates,two kinds of epoxy resins and concrete were studied by aging test of different immersion age under constant temperature artificial seawater.The physical and mechanical properties of the four kinds of FRP plates,two kinds of epoxy resins and concrete were measured,and the change of mechanical properties were studied.(2)The tensile bonding performance experiment of the bond resin under constant temperature artificial seawater immersion was carried out to study the durability of the adhesive resin.The bond resin with good durability and adhesion properties was optimized.(3)The mechanical properties and failure modes of FRP plate-concrete composite interface were studied by double-sided tensile shear test of FRP plate-concrete interface with different FRP plates,different epoxy resins and different interface forms under constant temperature artificial seawater immersion.The change of the maximum of shear stress,effective bond length and interfacial fracture energy with immersion time were also studied by the test.(4)The mechanical properties and failure modes of FRP plate-concrete composite interface were studied by conducting double-sided tensile shear test of FRP plateconcrete interface of four interface forms under the preloading dead load and constant temperature artificial seawater coupling.The change of the maximum of shear stress,effective bond length and interfacial fracture energy with immersion time were also studied by the test.