behaviour of a masonry arch bridge repaired using fibre-reinforced polymer composites

a two-span, single-ring semi-circular brick arch bridge was tested in this study, complete with fill material. each of the spans was initially loaded to investigate their response and to establish a four-hinge collapse mechanism, simulating damage prior to strengthening. frp strengthening was then applied to the two arches, and each of the spans was again tested separately until the failure of the strengthening system. the global (load and deflection) and local (crack width and frp strain) response of the structure was recorded. the frp strengthening resisted flexural crack opening in the masonry, and hence prevented a four-hinge mechanism collapse. failure instead occurred when the frp strengthening debonded from the masonry adjacent to an existing intrados hinge crack. as well as shear debonding adjacent to flexural cracks in the masonry, peel debonding occurred where shear deformation occurred across a masonry crack. catastrophic collapse did not occur, as the frp continued to contribute to the load capacity by acting as a tie after the ultimate load had been reached.