Seismic Performance of Precast Columns with Mechanically Spliced Column-Footing Connections

This paper presents the results from a large-scale experimental study that was conducted at the University of Nevada in Reno, NV. Five half-scale bridge column models were constructed and tested under reversed slow cyclic loading. The study focused on developing four new moment connections at column-footing joints for accelerated bridge construction in regions of high seismicity. The new connections were employed in precast columns, each using mechanical splices to create connectivity with reinforcing bars in a cast-in-place footing. Two different mechanical splices were studied: an upset headed coupler and a grout-filled sleeve coupler. Along with the splice type, the location of couplers within the plastic hinge zone was also a test variable. All precast models were designed with the intent to emulate conventional cast-in-place construction and, thus, were compared with a conventional cast-in-place test model. Results indicate the behavior of these new connections was similar to that of conventional cast-in-place construction with respect to key response parameters, although the plastic hinge mechanism could be significantly affected by the couplers.