Large-scale testing of retro-reinforced brick arches

Vertical static load tests on sixteen 2,95m span multi-ring clay brick arches were carried out to investigate the effectiveness of retro-fitted steel reinforcement as a strengthening measure. The principal parameters investigated were the arch geometry; arch ring thickness; area and distribution of reinforcement; type of inter-ring shear reinforcement and mortar strength. In each case a full width line load was applied incrementally to the upper surface of the arch at quarter span until collapse occurred. In all cases, longitudinal reinforcement was found to delay the onset of cracking and to increase the load carrying capacity. Radial dowels were found to be the most effective means of preventing ring separation and the simplest and quickest to install. Longitudinal reinforcement was found to be the most effective when used with measures to prevent ring separation.