Comparative bond characteristics of polymer concrete and UHPC for bridge joints: Reinforcement anchorage and substrate interface behavior

Polymer concrete (PC) has recently attracted attention as a potential alternative to ultra-high-performance concrete (UHPC) for closure field joints in accelerated bridge construction due to its rapid strength development. However, its broader implementation remains limited by incomplete understanding of its interaction with conventional concrete substrates and steel reinforcement. Previous studies have primarily focused on material-level properties of limited PC types, leaving bond performance and direct comparisons with UHPC largely unexplored. This study presents a comprehensive comparative evaluation of the bond characteristics of two PC systems—polymethyl methacrylate-based (PMMA-PC) and polyvinyl ester-based (PVE-PC)—relative to UHPC for reinforcing steel anchorage and splice behavior as well as substrate interface bond performance. The research consisted of an experimental program consisting of: (1) pullout tests to characterize rebar anchorage behavior; (2) splice tests to evaluate bond-controlled performance under bending; and (3) slant shear tests to assess interfacial bond strength with conventional concrete substrates under different mechanical and chemical surface preparation conditions. The results indicate that PC can serve as a viable alternative in accelerated bridge construction. In particular, PVE-PC exhibits superior bond performance relative to PMMA-PC and achieves rebar bond behavior comparable to UHPC at similar embedment lengths. Slant shear test results further demonstrate that the interfacial bond performance of PC can be significantly enhanced through surface preparation and the use of a bonding agent, achieving bond strengths greater than UHPC under conditions representative of typical field installation without using a bonding agent. The study concludes by proposing design recommendations for rebar anchorage length, lap splice detailing, and substrate interface treatment to support the implementation of PC in future bridge deck joints. • Bond performance of two PC types are compared with UHPC for bridge joints. • PVE-PC achieved rebar anchorage and splice behavior comparable to UHPC. • PMMA-PC showed lower but practically adequate bond performance. • PC–concrete substrate bond with bonding agents and surface treatment is superior to typical field application with UHPC. • Design-oriented recommendations for anchorage, splice length, and interface treatment are proposed.