Concrete Bridge Deck Reinforced with Textured and Nontextured Epoxy-Coated Bars

Abstract

The deterioration of bridge decks is a problem typically associated with the corrosion of reinforcing steel bars. This issue is partially controlled with the incorporation of epoxy-coating protection on the bars. However, later research demonstrated that the smooth surface resulting from the epoxy-coating application reduces most of the friction between the deformed rebars (with a manufactured pattern of surface ridges) and the surrounding concrete. Consequently, forces acting on the ribs of the rebars are reconfigured such that the radial components increase, triggering the early development of cracks. To mitigate both the reduction of bonding and the formation of cracks, the Illinois Department of Transportation proposed a new type of coated bars: textured epoxy-coated (TEC) bars. This study is a continuation of the research efforts aimed to evaluate the bond behavior of TEC rebars. The experimental program aims to explore and compare the impact of drying shrinkage, thermal, and flexural demands on the performance of two large-scale bridge deck specimens reinforced, individually, with TEC and standard epoxy-coated (EC) bars. The data collected from both specimens using digital image correlation and strain gauges make it possible to interpret the spatial distribution of strain during the performance of different tests. Precisely, from the shrinkage test, the results suggest that TEC rebars more actively resist the stress induced by the shrinking action. Regarding the thermal effect test, more but finer cracks develop in the specimen that incorporated the TEC bars. This observation implies an overall reduction of the reinforcement exposure to external agents. Ultimately, the results of the flexural test demonstrate that the TEC bars possess a higher resistance to slip and crack widening. The EC specimen, in contrast, demonstrates a lower stiffness under flexural demands, which can be related to the inferior engagement of the rebars to the concrete matrix.