Anchorage Strength and Behavior of Headed Bars in Exterior Beam-Column Joints

Thirty exterior beam-column joint specimens without transverse reinforcement were tested to measure anchorage strength with respect to anchorage configuration and embedment length. The anchorage behavior of bars terminated with a head and with a 90-degree hook is investigated and compared with each other and existing models. It is found that existing models based on idealized failure modes do not properly predict the concrete contribution to anchorage strength of headed bars terminated in exterior joints. A new model that accounts for head bearing and bond capacity of the anchored bars is proposed and calibrated using statistical analysis of the experimental results. The model conservatively estimates the anchorage strength of the headed bars terminated within exterior beam-column joints with sufficient side cover Features of the new model a e compared with the existing models.