Seismic Behavior of PC Column and Steel Beam Composite Moment Frame with Posttensioned Connection

Abstract

This paper presents test results of two large-scale precast concrete (PC) column/footing and steel beam subassemblies. In the model subassemblies, the steel beams were posttensioned by high-strength steel rods to the PC columns using an end-plate shop welded to a beam. The PC columns were connected to their footings using splice-sleeve method and dowel anchorage method, respectively. The objective of the test program was to investigate the seismic behavior of special moment resisting frames consisting of PC columns and steel beams in high-seismic regions. The detailed design approach of the proposed PC and steel special moment frames based on current seismic provisions was suggested and applied to the design of model subassemblies. Test results indicated that the PC and steel composite moment frame could be designed for resisting seismic load in terms of strength, drift ductility, and postyield deformation capacity. The test subassemblies also exhibited excellent strength and stiffness retention capacity even when the first-story drift ductility reached 5.0. In addition, the effectiveness of the two different column-footing connection types is evaluated in this paper.