Experimental investigation of precast concrete hybrid-steel concrete beam-column connections with self-centering system and steel slit dampers

This
study introduces a precast concrete hybrid-steel concrete beam-column connection incorporating a
self-centering system
and steel slit damper (SSDs) for seismic resistance. The objective is to utilize post-tensioned steel to enable the
structure to return to its original position (self-centering) after an earthquake, while SSDs are
designed to yield under seismic loads, absorbing and dissipating energy to
mitigate potential damage to the beam structure. The end of the beam is also
installed with H-section
steel beams to reduce the damage from SSDs. To evaluate the seismic performance
of the proposed structure, the study applies the capacity design approach to
control damage at the connection region. All test specimens were designed and tested following
ACI 374.1-05, using quasi-static reversed cyclic loading. The behavior of two connection
specimens was compared: 1) cast-in-place beam-column connection and 2) hybrid-steel concrete beam-column connections with unbonded
post-tensioned steels
and steel slit damper (SSD). The structural performance was
assessed based on the force-displacement
relationship, energy dissipation capacity, and stiffness. The test results indicate that a
crack formed at the beam-column
interface under lateral loads, known as a gap opening. However, the post-tensioned steel effectively closed
this gap, demonstrating self-centering
capability, while the SSDs efficiently dissipated energy through yielding. Furthermore, the specimens
exhibited stable behavior under large deformations, withstanding beam rotations
of up to 2% comparable
to the cast-in-place beam-column connection.