Anchorage performance of headed deformed bars in exterior beam-column joints under cyclic loading

The anchorage performance of headed deformed bars anchored in inter-story exterior beam-column joints under cyclic load was examined based on a test database with 118 test data. A proposed performance index based on the ACI 318 development length equation was used to evaluate the anchorage performance of the headed deformed bars of the specimens in the database. The results of the evaluation showed that the anchorage performance was positively correlated with the axial load, amount of joint transverse reinforcement parallel to the direction of applied shear, and head bearing area ratio, and was negatively correlated with the clear bar spacing and column moment ratio. Based on the evaluation, limits on design parameters (i.e., the minimum clear bar spacing, head bearing area ratio, concrete and steel strengths) were proposed. It was found that all the specimens in the test database showed satisfactory seismic performance if they satisfied the development length equation of the ACI 318 code and the proposed limits on design parameters.