Strengthening of RC slabs with large penetrations using anchored FRP composites

Large penetrations are routinely made in existing reinforced concrete (RC) slabs due to structural and/or functional changes. Externally bonded fibre-reinforced polymer (FRP) composites can in turn be bonded to the tension face of the slab in the immediate vicinity of the penetration in order to restore the strength of the slab due to the lost internal steel reinforcement. In order to prevent premature debonding failure of the FRP strengthening, anchors can be applied. The results of tests on the strength and behaviour of one-way spanning RC slabs with large central penetrations which have been strengthened with unanchored and anchored FRP composites are presented in this paper. The FRP strengthening was found to be effective in strengthening penetrated slabs and the anchors were found to be effective in controlling the propagation of debonding cracks.