Review of Bond-Slip Behavior between Rebar and UHPC: Analysis of the Proposed Models

Abstract

With superior mechanical properties and workability, ultra-high-performance concrete (UHPC) has been utilized extensively in engineering projects. To gain a comprehensive understanding of the bond behavior of UHPC or ultra-high-performance fiber-reinforced concrete (UHPFRC), researchers studied the factors influencing the bond-slip between rebar and UHPC or UHPFRC over the past few years. The literature-proposed ultimate bond strength formulas and the bond-slip constitutive model between rebar and UHPFRC are analyzed and compared. Based on the bond test database of UHPFRC, the results indicate that UHPFRC strength, relative concrete cover thickness, relative bond length, and steel fiber volume content are the primary parameters influencing the ultimate bond strength between rebar and UHPFRC. In the bond-slip constitutive model, the nonlinear ascending and linear descending model is more accurate than other models. This paper concludes by discussing the shortcomings in UHPC or UHPFRC bond research and predicting the future research trend.