The Effect of Bar Orientation on the Behavior of Column Splices

Column splices can either be oriented in a side-by-side configuration or an offset configuration. The purpose of this study is to examine experimentally the behavior of both splice orientations, and to present recommendations for their usage.

Four column specimens were tested and evaluated. Each had a 36-inch x 18-inch (914.4 x 457.2 mm) cross-section, and the columns were 13 feet (3.96 m) tall with both side-by-side and offset splices. In total, eight tests were performed considering the effects of the following variables: splice orientation, spacing between splices, and transverse reinforcement. Splice evaluations were based on bar stresses at failure, crack patterns, and modes of failure.

Test results showed that offset splices consistently had higher bond strengths than side-by-side splices. If a splice is designed assuming an offset orientation but constructed as a side-by-side splice, the bond strength may not be sufficient to develop the yield stress of the bars.