Experimental Study on Strengthening RC Beam–Column Joints with Inadequate Integrity using the Brick Wing Wall Installation Method

Beam–column joints constitute critical structural components in reinforced concrete (RC) frame systems, playing a pivotal role in ensuring seismic collapse resistance. Inadequate beam anchorage strength may lead to anchorage failure during seismic events, resulting in structural integrity loss and potential building collapse. Particularly in developing countries, where numerous vulnerable structures coexist with limited financial resources and technological capabilities, there is an urgent demand for simple and cost-effective strengthening methodologies. Bangladesh, characterized by its abundant and economical clay brick resources which are extensively utilized in construction, presents a unique context for structural reinforcement. This study proposes an innovative strengthening approach through the implementation of brick wing walls for RC structures exhibiting insufficient structural integrity. Three specimens representing the deficient exterior beam–column joints were manufactured, with two strengthened using distinct wall configurations: thin-long walls and thick-short walls. Quasi-static cyclic loading tests were conducted to evaluate the strengthening efficacy. Experimental results demonstrated that the control specimen experienced structural integrity failure attributable to insufficient beam anchorage strength. In contrast, both strengthened specimens successfully prevented anchorage failure and achieved an optimal beam-yielding mechanism. The thin-long wall-strengthened specimen exhibited superior strength performance, demonstrating enhancements of 62% and 164% under positive and negative loading conditions, respectively, compared to the prototype specimen. However, rapid strength degradation was observed after reaching the peak strength. In contrast, the thick-short wall-strengthened specimen exhibited relatively lower strength but significantly improved ductility, with increases of 45% under positive loading and 151% under negative loading. Furthermore, finite element analysis was conducted to investigate the stress distribution patterns within the brick walls. The analysis revealed the formation of a compressive strut in the compressed brick wall and a tensile force in the tensile support column. Based on these findings, a comprehensive mechanical model and corresponding design methodology for structural strengthening applications were developed.