Seismic response of a rocking bridge column using a precast hybrid fiber-reinforced concrete (HyFRC) tube

With the expected replacement of deteriorated reinforced concrete bridges to occur in the next several decades, an opportunity exists to design more economic bridge columns in seismically active regions which are rapidly constructed while having enhanced crack resistance for extended service life. A precast hybrid fiber-reinforced concrete (HyFRC) tube, which contains a column's steel reinforcement, is proposed for accelerating construction and is to be filled with plain concrete at the construction site. An experimental column was subjected to static, uni-directional, cyclic loading and utilized a base-rocking design for further ductility enhancement. At the conclusion of the test, the column reached a peak drift ratio of 13.1% and showed minor damage, including elimination of cover spalling. The HyFRC tube column design contributed effective resistance against longitudinal reinforcing bar buckling, allowing the column to maintain 93% of its peak load capacity at 9.5% drift. Compared to a monolithic HyFRC column, the precast HyFRC tube column was constructed with less HyFRC volume while having similar seismic performance, making it a more sustainable alternative.