Rehabilitation of damaged RC bridge piers through rebar replacement: Experimental study at different scales and numerical modeling

This study evaluates a rehabilitation technique for damaged reinforced concrete (RC) bridge piers involving rebar replacement, with experiments conducted at two scales (1:6 and 1:3). Self‐compacting concrete (SCC) and ultra‐high‐performance concrete (UHPC) were employed as rehabilitation materials. A simulation approach applicable to various scale factors was developed, validated against experimental results, and subsequently extended to full‐scale piers. The results indicate that the reduced scale specimen can predict the behavior of the original structure after the rehabilitation, which was proved to be effective as piers of different sizes exhibited consistent and satisfactory performances. For SCC rehabilitations, the horizontal force capacity was only partially restored (about 85% of the original value) due to the use of reduced‐diameter rebars, although energy dissipation was largely recovered and ductility was significantly enhanced. In contrast, UHPC rehabilitations improved horizontal force capacity to about 105% of the original value, while also enhancing energy dissipation and ductility. The CFRP wrapping provided excellent confinement, and from a cost‐effectiveness standpoint, the wrapping height only needs to slightly exceed the rehabilitation region.