Experimental studies on the strength of reinforced concrete elements with lap joints of compressed reinforcement in a single design section under axial compression

Introduction. Current Russian standards impose stricter requirements on the overlap length of reinforcing bars in lap joints executed within a single section of the structure compared to staggered lap joints. Due to insufficient research on this issue concerning compressed reinforcement, these requirements lack comprehensive justification and have been adopted with some caution, which leads to increased reinforcement consumption. This implies investigating various possible design solutions for lap joints of reinforcement bars made in a single design section and experimental verifying of their impact on the strength of compressed reinforced concrete elements under static loads. Aim. To conduct experimental studies on the load-bearing capacity of compressed reinforced concrete elements with different variants of lap joints of reinforcement located in a single design section. Materials and methods. Experimental studies were conducted by testing reinforced concrete elements subjected to centrally applied static compressive loads. The studies were carried out in accordance with the provisions of current standards. Results. Experimental data were obtained regarding the strength of reinforced concrete elements with various types of lap joints of reinforcement located in a single design section under axial compression. Conclusions. Experimental studies have determined the failure loads and the failure patterns in the test samples. Failure for all test samples occurred outside the lap joint. Depending on the design solution of the sample, the values of failure loads for the studied samples with lap joints of reinforcement were lower by an average of 4 % than for samples without joints or higher by 2–3 %.