Modeling Local Bond Stress-Slip Relationships of Reinforcing Bars Embedded in Concrete with Different Strengths

Although many different analytical models of local bond stress-slip have been proposed, considering the possible differences between materials in different countries, their applicability needs to be further explored. In this paper, the local bond stress-slip characteristics of reinforcing bars embedded in concrete with different strengths were experimentally studied. The experimental variables included the concrete strength (20, 40, and 60 MPa) and deformed rebar size (#4, #6, and #8). The experimental results of the bond stress-slip relationship were compared with the Euro-International Concrete Committee (CEB-Comité Euro-International du Béton)-International Federation for Prestressing (FIP-Fédération Internationale de la Précontrainte) Model Code and prediction models found in the literature. In addition, based on the test results, an empirical model of the bond stress-slip relationship was proposed. The evaluation and comparison results show that, regardless of the concrete strength grades, the predicted value calculated using the CEB-FIP Model Code will underestimate the bond strength of the specimens with different steel bar diameters. From this perspective, it is more conservative. In contrast, the proposed model can predict the test results with a reasonable accuracy.