Seismic performance study of plastic hinge region using PVA-ECC composite bridge piers

This study explores the use of high tensile ductility engineered cementitious composites (ECC) to replace the plastic hinge region in conventional reinforced concrete (RC) pier, aiming to enhance seismic performance. Experiments and numerical simulations were performed on a traditional reinforced concrete pier and three composite piers with different replacement heights of ECC in the plastic hinge area. The findings demonstrated that the use of ECC led to a substantial enhancement in the piers' ultimate displacement, displacement ductility factor, and energy dissipation capacity, with improvements of more than 20.3 %, 17.1 %, and 80 % correspondingly. Increasing the replacement height from 300 mm to 400 mm boosted the displacement ductility coefficient by 10 %. Numerical analyses corroborated these findings, indicating a decline in seismic performance with higher axial pressure ratios. At an axial pressure ratio of 0.2, ductility increased by over 1 % for every 100 mm increase in ECC height up to 400 mm, beyond which the increase was less than 1 %. Thus, ECC in the plastic hinge improves seismic performance, with greater enhancement discovered at higher replacement heights within a certain range.