According to concrete features the investigation of bond strength of reinforcement in reinforced concrete elements subject to combined bending

IV ABSTRACT Phd Thesis ACCORDING TO CONCRETE FEATURES, THE INVESTIGATION OF BOND STRENGTH OF REINFORCEMENT IN REINFORCED CONCRETE ELEMENTS SUBJECT TO COMBINED BENDING Kazan TÜRK Fırat University Graduate School of Natural and Applied Sciences Department of Civil Engineering 2002, Page: 96 The primary aim of this study was to develop an empiricial equation, which could used to define bond strength of reinforcement. In this study, twenty seven beams, which were produced from fc >30 MPa concrete and had large size, were tested. Each beam was designed to include two bars in tension, spliced at the center of the span. The splice length was selected so that bars would fail in bond, splitting the concrete cover in the splice region, before reaching the yield point. In all experiments, the variables used were the reinforcing bar diameter and loading condition. In the first series experiments, nine beam specimens were loaded in positive bending with the splice in a constant moment regioa In the second and third series experiments, total eighteen beam specimens were subjected to axial pressure force in addition to positive bending. As results, bond strength reduced as the bar diameter increased but axial pressure force for the same bar diameter increased both bond strength and ductility. Key Words: Beams, bond of reinforcing bar-concrete, deformed bar, combined bending, splice length.