Influence of water immersion on the bond behavior between CFRP and concrete substrate

This paper presents an experimental study on the effect of water immersion on the behavior of bond between a CFRP plate and concrete substrate. The results show that the fracture energy was reduced significantly after 6 months immersion in water but it remained close to constant when the immersion time further increased. They also show that the higher the concrete compressive strength, the more significant the deterioration. The failure mode of the CFRP-to-concrete bonded joint in a single shear pull-off test shifted from a concrete cohesion failure to debonding at the primer/concrete interface. Under the microscope, the failure mode in the aged specimens was a combination of mortar cohesion failure and primer-mortar de-bonding failure.