Normal section strength of eccentrically compressed reinforced concrete structures with loop reinforcement joints. Experimental studies

Introduction. The current RF regulatory documentation contains only general instructions on the structural requirements for loop reinforcement joints in reinforced concrete structures without accounting their influence on the bearing capacity of normal sections, in particular, eccentrically compressed elements. These circumstances limit designers and may have a negative effect on the reliability of design solutions. In this regard, it seems necessary to investigate various possible structural options of loop joints and experimentally check their effect on the normal section strength of eccentrically compressed elements under static loads.Aim. To conduct experimental studies of the bearing capacity for normal sections of eccentrically compressed reinforced concrete elements with various options of loop reinforcement joints.Materials and methods. Experimental studies were carried out by testing reinforced concrete elements under an eccentrically applied static compressive load, taken into account the requirements of the current regulations. Results. The result of the studies involve experimental data on the normal section strength of eccentrically compressed reinforced concrete elements with various options of loop reinforcement joints, as well as data on their stiffness and crack resistance.Conclusion. According to the results of experimental studies, destructive loads, cracking patterns, and deflections of test samples were determined. For all eccentrically compressed samples with loop joints, the strength of normal sections is lower by 3–12 % than the strength of control samples without reinforcement joints. This reveals a tendency of a bearing capacity to increase as the length of the straight insert at the joint, as well as the area of the transverse reinforcement in the joint area, increases. Further, a more detailed publication of the obtained experimental data is planned.