Finite Element Analysis On Bond Behavior Of The Interface Between GFRP-High Strength Concrete

Glass Fiber Reinforced Plastic/Polymer (GFRP) is widely used in concrete structure strengthening because of its high strength-weight ratio,corrosion-resistance and cheapness etc. But there are many problems unsoluted in strengthening high-strength concrete and few researches in China. Although there are many experiments carried, finite element analysis is relatively lagged. Researches on debonding failure modes of interface between GFRP-High strength concrete were performed with finite element method, investigated to provide a reference for anti-peeling-off design.There are many scholars carried lots of researches on strengthening ordinary concrete with FRP, and received many useful conclusions.So researches on the interfacial bonding behavior between GFRP and High Strength Concrete with finite element method is studied combining with the research programs of National Natural Science Foundation of China (50878035) and support programs of national science and technology (2006BAJ03A03-09 and 2006BAJ06B07-05). Numerical simulations of the single-face shear type experiment of high strength concrete specimen bonded with GFRP are carried out, considering the effects of different bongding length, width and thickness of GFRP to the interface behavior between GFRP and High Strength Concrete.Conclusions are received as follows.1. Finite element numerical simulation of the interface failre mode between GFRP and High Strength Concrete are carried out considering different bond length,width and stiffness of the bonding GFRP, with different strength grades of concrete prism being C50,C60.2. Based on finite element analysis results, failure modes of the interfacial are illustrated from point of micro-mechanics and the mechanism of bond failure is analyzed.3. Based on the bond stress and strain received by the numerical simulation, bond mechanism is studied deeply. The distribution and the development of the stress and strain in the process of debonding are studied.4. The influences of bonding length and width of GFRP to ultimate capacity load are studied emphatically. The FEA resluts are examined with experiment results of bibliography [9] and calculate results of Chen-Teng and Yang formulas.The paper points some deficiencies when applying the two formulas in GFRP-High strength concrete ultimate bearing capacity and proposes some corrections for the effective bond length,the coefficient of GFRP bonding length and bongding width for Chen-Teng formulas.