Investigation on the seismic behavior of exterior beam–column joint using T-type mechanical anchorage with hair-clip bar

In reinforced concrete structures, it is essential to enhance the performance of beam– column joints in moderate and severe seismic susceptibility areas. An attempt has been made to study and evaluate the performance of exterior beam–column joint using proper reinforcement anchorage and joint core detail. The anchorages are detailed as per ACI-352 (Mechanical anchorage), ACI-318 (90° Standard bent anchorages) and IS-456 (Full anchorage) along with confinement as per IS-13920. Significant improvements were observed in seismic performance, ductility and strength while using proposed hair-clip bar plus X-cross bar in combination with mechanical anchorage detail for higher seismic prone areas, apart from resolution to reducing congestion of reinforcement in joint core. To assess the performances of anchorages and joint details, two groups of three specimens each were tested under reversal loading. The test results are evaluated and presented in this paper.