Reinforced Concrete Bridge Deck Repair with Titanium NSM

The use of titanium bars as a near surface mounted (NSM) repair method for highway bridge deck slabs is investigated in this pilot study. Four full-scale slabs had half of their internal reinforcing steel cut resulting in an approximately 40% loss of slab capacity; these represented ‘damaged’ slabs. The objective of this study was to evaluate the performance of replacing these two cut bars in order to restore the original capacity of the slab. The four slabs were repaired using NSM titanium bars designed to restore either their capacity or stiffness of the cut bars. One slab from each group was repaired using a full-length straight bar while the other implemented a ‘staple’ type repair. Both approaches effectively restored the capacity of the slabs although each had significant impacts on the available ductility of the repaired slab. Repairs based on restoring lost bar strength resulted in preferable behavior. Restoring lost stiffness required four times as much titanium and resulted in over-reinforced sections showing little ductility.