Experimental evaluation of the effect of partial saturation of construction moisture on CFRP-concrete debonding

The mechanical strength of FRP reinforcements for concrete elements is greatly affected by the presence of water in the concrete. A great number of investigations has concerned the effects of moisture cycles in various conditions, simulating environmental degradation. In the paper are reported the results of an experimental investigations on the strength of FRP reinforcements installed on partially saturated concrete samples. Pull-off tests and Double Shear Tests were performed at three degrees of partial saturation. The resistance of the reinforcement at pull-off (which is a test used for assessing the conformity of existing reinforcements) was found to degrade by a larger amount than the resistance at shear. The failure mode was found to shift from fibre breakage to partial delamination in which part of the detachment occurred at the interface.