Mechanical Behavior of Repaired Beams Under Static Loading

A total of 15 repaired and unrepaired reinforced concrete beams were tested under static loading in this study. The beams were of rectangular cross-section, 100 x 120 mm, and tested in flexure in simply supported mode on a span of 600 mm under a line load at mid-span. These include control beams, which were unrepaired, and beams repaired by shotcreting prepacked material, shotcreting mortar, casting prepacked material and casting prepacked material with steel fibres. The performance of the repaired beams statically-loaded to failure was monitored. The influence of differential shrinkage between repair material and substrate, bonding strength, casting method and the presence of steel fibres on the mechanical behaviour of repaired beams are discussed in this paper. The test results indicated that the mechanical properties of the repaired beams were significantly affected by differential shrinkage, the mechanical properties and the mix proportions of the repair materials used, and the repairing methods employed. The flexural stiffness of the repaired beams could be increased by using steel fibres, improving the bond quality between substrate and repair materials, and selecting appropriate repair method.