Experimental and numerical investigation of the bond behavior of smooth and sand-coated rebar in concrete by flexural bond test method

Abstract

Reinforced concrete behavior can be exhibited by the acting of steel rebar and concrete together. This situation produces full adherence acceptance of the steel rebars and concrete interface for use in simple empirical calculations. However, the bond-slip model may be important in more realistic and comprehensive models. This situation causes other factors that create adherence to come to the fore, due to the lack of mechanical clamping in smooth surfaced bars. For this reason, it is important to define the bond-slip models accurately to the numerical models when constructing the numerical model of this type of rebars. In this study, two flexural bond experimental test specimens reinforced with smooth surface steel bar and reinforced with sand coated steel bar were prepared. These two samples were tested comparatively in terms of load bearing capacity, vertical displacement capacity, slip and collapse mechanism. As a result of the investigations, boundary values have been proposed for the BPE model, which is also recommended by the CEB-FIP (2010) model, to be used in both smooth surface and sand-coated surface. In addition to these, numerical models with different embedment lengths were created in the light of experiments and proposed BPE models. It was concluded that the embedment length significantly affects the maximum load capacity in the numerical models created.