research investigated the effect of interface region relative humidity (IRRH)
on the bond between CFRP and concrete using computer simulation technique.
After FRP is peeled off concrete substrate, there is a layer of residue
concrete on the detached FRP if the bond is sound. The experimental program
related to this research found that the residual thickness of concrete (RTC)
was directly related to the IRRH. A constitutive equation, which calculated the
RTC from IRRH, was proposed in this research based on the experimental data.
The calculated RTCs were used to build a series of finite element models and
the virtual crack closure technique (VCCT) was used to calculate the bond
fracture energy Gf for
debonding. Through the RTC, the bond fracture energy Gf was related to the interface region relative humidity (IRRH). The model
and FEM results had excellent agreement with the experimental data. These
models can be used to simulate the bond degradation for CFRP bonded concrete
specimens suffering from moisture attack.