Experimental study on seismic behavior of full-scale fully prefabricated steel frame: Global response and composite action

To investigate the seismic behavior of a fully prefabricated steel frame with new type construction process, to provide a unique set of data on frame test, and to lay the foundation for follow-up research, a full-scale test was performed under cyclic loads. This frame was composed of box cold-formed columns, hot-rolled I-section beams, end-plate joints, rod flexible braces, and prefabricated concrete slabs. A recently proposed type of bolted end-plate joint and a new proposed construction method were used in this test. Because limited concrete casting and field welding were involved during the structural assembly process, construction efficiency was improved. The design details of the test specimen, the test setup, the loading protocol, the construction process, and the measurement arrangement are introduced. Test observations of braces, beams, joints, columns, and slab behavior are described in detail. Hysteresis behavior of the frame is discussed, including hysteresis curves, backbone curves, overall deformation and energy dissipation behavior. The composite action of the prefabricated slabs under cyclic loads is also studied. The results indicate that the specimen exhibited satisfactory cyclic behavior, horizontal load-carrying capacity and ductility performance, with no obvious degradation in strength was observed even at the large overall drift ratio of 7.69%. Plastic hinges formed at beam-ends and column bases. The frame's lateral stiffness in the initial position degraded significantly following brace buckling, however, no soft-story mechanisms were developed.