Earticle

This study aims to evaluate the ultimate shear strength of the connections of composite steel beam(CSB) composed of reinforced concrete (RC) column and steel beam. Total number of specimens of CSB were 66 carried out by researchers in domestic and foreign countries. The specimens were considered with various types of shear reinforcement such as shear reinforcement of vertical and end concentration, band plate and stud bolt and welding of main bar, etc. Ultimate shear strength of the connections with various reinforcement types was evaluated through experiments and code equations. In this study, experimental result were compared with code formula(KBC-RC, JIS-RC, JIS-SRC) and Zsutty`s Equation. The average test-to-code ratio of ultimate shear strength for all specimens was 1.05(KBC-RC), 1.59(JIS-RC), 1.16(JIS-SRC), and 0.96(Zsutty). Categorized by shear reinforcement type of specimen, ultimate shear strength by code formula and Zsutty’s equation deviated from 6% to 41% from experimental results and the average of deviated percentage was 25%(KBC-RC), 29%(JIS-RC), 29%(JIS-SRC), and 21%(Zsutty). Specimen reinforced at end with fixed plate showed the best correlation with code formula and Zsutty’s equation.

RCS construction method is to take an advantage by applying reinforced concrete column and steel beam. RCS construction method has a complex structural analysis, compared with single structural system, due to interaction of different material, behavior of load distribution, diversity of joint detail and failure behavior. Therefore, this study aims to describe behavior of RCS joint as a simplified analysis model. The first, for understand behavior of RCS joint through test literatures related to RCS from the inside and outside of country and presented an analysis model, which to reflect each characteristic. So first of all, the researcher divided RCS specimen into four groups, according to its form and stress distribution element. The 'C' group, which is a flexural failure model, was explained properly using a factor in not order to generate stiffness reduction, strength reduction and pinching with polygonal model. The 'A', 'B' and 'D' groups, which are origin oriented models, were explained properly using smooth model and they had little bigger values in stiffness and strength reduction than general RC joint and a factor of pinching was explained through a combination among slip length, slip sharpness and moment level of slip in each group.