Performance of Headed Reinforcing Bars in CCT Nodal Regions

The use of headed reinforcement in concrete bridge applications offers a partial solution to congestion and anchorage problems. Heads eliminate the need for standard hooks and can reduce straight-bar anchorage lengths. Use of headed bars is not widespread due to the lack of coverage in provisions. Common use of headed bars is not likely until satisfactory provisions are developed.

This research explored the performance of headed reinforcement in compression-compression-tension (CCT) nodal regions. Fifteen tests were performed on specimens with varying head size, head shape, specimen width, and base plate length. Mode of failure, failure load, deflection under the load point, slip of the bar, strain along the bar, and crack patterns were analyzed to determine trends in behavior.