Cyclic behaviour of precast beam-column connections with shear key and hybrid rebar coupler: An experimental study

The current work attempts to examine the cyclic behaviour of the proposed shear key based precast beamcolumn wet connections. The configurations consist of shear keys, fiber reinforced composites and interface treatment between beam & column. The rebar continuity between the precast beam and column was established using hybrid rebar couplers. Six precast specimens and one monolithic joint were cast and tested under reversed cyclic loading. The seismic performance of the connections was assessed and discussed in terms of hysteretic behaviour, stiffness and strength degradation, damage tolerance, displacement ductility, energy dissipation characteristics, and joint principal tensile stresses. The strength enhancement, dissipated energy, stiffness retention of precast specimens was similar to monolithic specimen. The crack patterns revealed the influence of stiffness of coupler in the plastic hinge region with shifting of cracks next to coupler and joint region. Also, the presence of fiber reinforced composites, shear key and interface treatment in the connection region exhibited controlled cracking in the plastic hinge region and restricted the joint shear failure. The obtained results were validated through ACI 374.1-05 requirements criteria, which shows the acceptable seismic behaviour. The findings obtained from this study demonstrated the integrity of proposed beam -column connections against seismic forces and could achieve emulative design philosophy.