Investigation on ultimate shear strength of SRC interior beam-column joints

Experimental and analytical studies were carried out in order to clarify the stress-transfer mechanism of SRC interior beam-column joints. The variables examined were beam-column depth ratio, concrete strength, and the shapes of steel and concrete in a horizontal cross-section. All of the SRC specimens failed in joint shear. The experimental results showed that the shear strength of a beam-column joint depends on the beam-column depth ratio and the shape of the joint cross section. Therefore, the ultimate shear strengths of the SRC beam-column joints calculated by using the AIJ-SRC standard equation did not agree with the experimental values. The analytical results showed that the shear strength of a shaped steel joint could be estimated from measurements of the shear strengths of the following three components: the joint web plate, the joint flange frame and transverse flanges. The following conclusions were drawn from the results: 1) the sheer strength of a steel joint web can be accurately estimated by using the AIJ-SRC standard equation, 2) calculation of shear strength of a joint flange frame using an inelastic model results in overestimation, 3) the shape of the joint cross section affects the shear strength of the transverse flanges, 4) calculation of sheer strength of concrete reinforcement using the AIJ-SRC standard equation results in overestimation, and 5) ultimate shear strength of an SRC beam-column joint can be accurately estimated by using the proposed equation.