Durability of CFRP bonding system under freeze-thaw cycling

Abstract

This paper presents the results of an experimental study on the behavior of externally-bonded fiber reinforced polymer (EB-FRP) joints under freeze-thaw cycling. Four series of single shear tests were conducted on 26 specimens. The parameters considered were the exposure condition, concrete grade, and the number of freeze-thaw cycle. The behavior of the CFRP-concrete interface in the shear direction was investigated. The test results demonstrate that the bond strength, bond stiffness, interfacial fracture energy, and maximum slip of the joints decrease with the increase in the number of freeze-thaw cycle, and also are affected by the testing environment. It is also found that the depth of the cracking and the effective bond length increase with an increase in the cycle number, and thus affecting the bond stiffness and strength. The deterioration of the bond strength is considered due to the damage of the concrete under the freeze-thaw cycling. © Tsinghua University Press, Beijing and Springer-Verlag Berlin Heidelberg 2011.