Quasi-Static Testing of a Damage Protected Beam-column Subassembly with Internal Lead Damping Devices
Multiple reversed cyclic quasi-static tests are performed on an 80 percent scale 3D beam column joint subassembly. The physical model is taken from an exterior connection of a jointed precast concrete frame prototype structure that is designed for damage avoidance. Unbonded post-tensioned prestress is provided by high-alloy high-strength threaded bars. Draped and straight tendon profiles are used in the transverse and orthogonal directions, respectively. The joint region is armoured to avoid damage by providing steel plates at the rocking edges of the beam-column interface. Supplemental energy dissipation is provided by high-performance lead-damping devices cast internally in each beam. A combination of couplers and cast in-situ closure pours at the beam ends are used to ensure reasonable construction tolerances. Column axial load and floor dead load are simulated. The global performance of the subassembly and the efficiency of the lead dampers is critically discussed. The subassembly had negligible residual displacements and minimal damage after the test. The hysteresis loops showed stable energy dissipation indicating the success of the dampers. Relatively simple hand methods of predicted performance are shown to conform to the observed experimental behaviour.