Cyclic behavior of precast concrete beam-column connection using steel fiber reinforced cast-in-place concrete

Three equivalent exterior precast concrete beam-column (PCBC) connections have been investigated in this study in orderto analyze the effect of steel fiber reinforced concrete (SFRC) as cast-in-place (CIP) on the seismic performance of the PCBC connection. The connection was designed as a ductile connection for a moment-resisting frame and consists of a precast U-beam, precast column with corbel, interlocking bars, and CIP-concrete to connect the precast beam to precast column. The volume fractions of steel fiber incorporated within the CIP-concrete were 0%, 0.5% and 1%. A quasi-static load was applied vertically to the beam tip of the PCBC specimen. The results showed that the steel fibers contained within the CIP-concrete provided 2% increase of the maximum load, 17.7% increase of the energy dissipation, and increase in the joint stiffness of the PCBC connection. The steel fibers delayed the onset of cracking and slowed down the crack propagation, resulting in shorter cracks in the joint core of PCBC specimen, which correlates well with the deflection-hardening characteristic found from the modulus of rupture test.