Experimental Investigation of Surface Preparation on Normal and Ultrahigh-Performance Concrete Interface Behavior

Many bridges in the United States are classified as structurally deficient and many others are nearing the end of their design service life, necessitating robust and durable bridge rehabilitation methodologies. States' department of transport have recently developed innovative solutions for accelerated bridge construction using Ultrahigh Performance Concrete (UHPC) as grout material between prefabricated bridge components or as an overlay over existing bridge decks to increase their service life. The normal strength concrete (NSC)-UHPC interface behavior is critical in determining the overall performance of such NSC-UHPC composites. In this study, an experimental investigation was performed to quantify the effect of surface preparation and interface reinforcement on NSC-UHPC interface performance. The results from this study were compared with the current design guidelines for estimating interface shear capacity. In general, it can be concluded that increasing roughness depth and reinforcement area has a positive effect in interface shear capacity.