Studies On Bonding Behavior Of BFRP-Concrete Interface

As a new type of reinforcement material,Basalt Fiber Reinforced Polymer(BFRP)is widely used in civil engineering field because of its advantages of light weight,high strength,corrosion resistance,good fatigue performance and non-magnetic properties.As a reinforcement material,FRP mainly bonds FRP and concrete into a whole by epoxy resin.Therefore,the bond mechanical properties of FRP-concrete interface are important factors affecting the reinforcement effect,and also the basis for the joint work of FRP and concrete.Domestic and foreign scholars have done a lot of experimental research on FRP reinforced concrete structures,but most of the reinforcement materials studied at present are carbon fiber(CFRP)and aramid fiber(AFRP),but less research on cost-effective basalt fiber(BFRP).The subject of this paper comes from the key project of Jilin Province's scientific and technological research project,“Application Technology Development of Basalt Fiber in Structural Reinforcement Project in Seasonal Frozen Zone”(20180201079SF)and Jilin Provincial Development and Reform Commission Industrial Innovation Special Fund Project(2017C050-3).The research content is an important research content of the two projects.In this paper,the double-shear test is used to study the bond behavior between BFRP plate and concrete interface.The main research contents are as follows:(1)This paper designed double shear specimens with various influencingfactors,considering the influence of concrete strength grade,bond length,rubber layer thickness and bond width on interface bond behavior,providing a wide range of samples for the conclusion of the test,has great application reference value.(2)According to the test phenomenon,the failure mode of BFRP-concrete interface is expounded,and the influence of various influencing factors on the interface bearing capacity is analyzed.The load-end slip curve is drawn based on the experimental data.(3)Comparing the experimental data with the existing bond strength model,pointing out the shortcomings of these models;the local shear stress and slip value of the interface are obtained by calculation,and the shear stress distribution and bond slip curve of the interface are given.And the effective bond length value;the Popovics model and the hyperbolic model were used to fit the test data,and the bond-slip constitutive relation of BFRP-concrete interface was proposed.