Experimental Investigation on Seismic Performance of Precast Hollow Column-Footing Socket Connections Using Ultrahigh-Performance Concrete

The study examines the potential of ultrahigh-performance concrete (UHPC) to reduce embedment lengths in member socket connections (MSCs) for precast bridge columns. Two quarter-scale MSC specimens were tested under quasi-static reversed cyclic loading: a reference with normal concrete (NC) and a UHPC-enhanced specimen with 20% shorter embedment. The UHPC specimen exhibited 36% higher load capacity, 10% greater ductility, 4% improved energy dissipation, and 10% lower residual drift. The failure mode transitioned from flexure-controlled to combined flexural-slippage. Findings demonstrate that UHPC enables shorter, more economical MSC designs while maintaining excellent seismic performance.