Innovative retrofitted reinforcement techniques for masonry arch bridges

This paper describes a series of load tests to determine the effectiveness of two innovative repair systems for masonry arch bridges containing the common defect of ring-separation. Two arches were strengthened using the Helibeam system, one using a prototype version and the other using a modified version. Two further arches were strengthened using the masonry arch repair and strengthening (MARS) system, again using a prototype and modified system. The effectiveness of the repair systems is evaluated by comparing the behaviour of the strengthened arches with an unstrengthened arch containing ring-separation. For comparison purposes, an additional test was carried out on a fully bonded arch (that is, with no ring-separation). The testing demonstrated that, following some modifications to the initial installation procedures, both retrofitted strengthening systems generated significant increases in load-carrying capacity when compared with the ring-separated and the unstrengthened arch. Some recommendations on practical limitations with particular regard to the safety of the structure during installation of the strengthening system are also given.