Bond-slip model for rebar mounted to high-strength grouting material

The anchorage performance of reinforcement in high-strength grouting materials plays a decisive role in the safety of prefabricated reinforced concrete structures. At present, the design value of anchorage length of reinforcement in grouting materials or concrete in the codes of various countries is conservative, generally greater than 20 times the diameter of reinforcement. Moreover, the anchorage length is the empirical value obtained from the test of connecting the reinforcement with the grouting sleeve and is not based on the bond-slip performance of the reinforcement and the grouting material. Therefore, based on the interface bond-slip performance test of two media, this paper comprehensively considers the influence of reinforcement diameter, strength grade, anchorage length, and high-strength grouting material strength on the ultimate bond strength, gives the calculation formula of anchorage length and establishes a nonlinear three-segment bond-slip constitutive model. The research in this paper shows that the anchorage length between high-strength grouting material and reinforcement to ensure bonding safety is 7.1 d–10.8 d, which is far less than the recommended anchorage length in the specification. It can provide a reference for the design of prefabricated structures based on grout-anchored reinforcement connections. •Providing a reference for the minimum anchorage length considers the interface bond-slip performance.•A bond-slip constitutive model for rebar and high-strength grouting material was proposed.•Rebar diameter, strength grade, anchorage length, and grouting material strength affect ultimate bond strength.