Strengthening of masonry arches with fiber-reinforced polymer strips

This paper deals with masonry arches and vaults strengthened with surface fiber-reinforced polymer (FRP) reinforcement in the form of strips bonded at the extrados and/or intrados, considering strip arrangements that prevent hinged mode failure, so the possible failure modes are: (1) crushing, (2) sliding, (3) debonding, and (4) FRP rupture. Mathematical models are presented for predicting the ultimate load associated with each of such failure modes. This study has shown that the reinforced arch is particularly susceptible to failure by crushing, as a result of an ultimate compressive force being collected by a small fraction of the cross section. Failure by debonding at the intrados may also be an issue, especially in the case of weak masonry blocks or multiring brickwork arches. Failure by sliding has to be considered if the reinforcement is at the extrados and loading is considerably nonsymmetric.