Serviceability characteristics of flowing repairs to propped and unpropped bridge structures

The paper presents the results of a field investigation of repairs to Sutherland Street Bridge on B6080 in Sheffield, England. Flowing repair materials were used to apply large patch repairs to propped and unpropped columns of the bridge. Watertight shuttering was securely attached to the structure and flowing repair materials were either pumped or poured into the shuttering. The elastic modulus of the repair materials (E-rm) used was greater than that of the substrate concrete (E-sub). The results show that free shrinkage of the repair patch is effectively transferred to the substrate when E-rm > E-sub and the risk of restrained shrinkage cracking is reduced. In a propped repair, long-term strain distributions in the repair patch are erratic and are predominantly governed by the depropping process; properties of the repair materials only have a secondary influence. The repair patches applied with flowing materials did not, in the 60 week monitoring period, redistribute any significant external loading from the substrate member.