Experimental Study On Bond Behavior Of FRP-ECC-Concrete Composite Interface

A large number of buildings after many years may induce structural failure in case of natural or man-made, such as structural aging, design errors. The most common method of reinforcement beam is externally FRP method, and the most typical failure mode of the beam strengthened by FRP is the middle part of FRP which is caused by the bending crack. Due to ECC material ductility and its crack at failure is very small, using its characteristic of "seamless concrete", if a layer of ECC is added between the concrete and FRP, there may delay debond or even bond. It will change common FRP debond style. Maybe ECC will solve middle stripping. In order to ensure the normal operation of the structure, the bonding property of FRP-ECC- concrete composite interface needs to be studied. This paper focuses on the experimental study on the bond behavior of FRP-ECC- concrete composite interface. It Consists of two parts: the first part is the ECC as repair layer and adhesive single shear test, is mainly studied in pure shear state FRP-ECC- of concrete interfacial bond strength; the second part is due to beam with bending effect, the ECC as repair layer and the bonding agent for three-point bending notched beam tests to study the in bending shear interfacial bond properties of concrete FRP-ECC- state. The following studies are carried out:(1) This paper study on the effect of different surface treatment methods on the bond behavior of FRP-ECC- concrete interface;(2) This paper study on the effect of different ECC thickness on the bond behavior of FRP-ECC- concrete interface. Through the FRP specimens placed on different thickness of ECC paste of single shear specimens, and flexural experiment in treated test piece pouring different ECC, to make the FRP stripping on both sides, get the influence of thickness of ECC on the interfacial properties of FRP-ECC- concrete.(3) This paper study on the effect of different uses of ECC on the bond behavior of FRP-ECC- concrete interface. ECC as a binder to replace the traditional cementitious materials paste FRP and ECC as a patch with epoxy resin bonded FRP, ECC of different uses for the FRP-ECC- concrete interface bond performance. Through the experimental study. Analysis different surface treatment, ECC for various thickness and different use build failure mode, bearing capacity, effective bond length, shear stress distribution, Bond-Slip, Load-slip, Load-Deflection relationship and so on.