Seismic performance of precast concrete columns with prefabricated UHPC jackets in plastic hinge zone

The plastic hinges of precast concrete columns with grouted sleeves commonly occur at the column-footing connection regions, leading to difficulties in the repair and rehabilitation of precast concrete structures after catastrophic events. In this paper, new structural details are proposed to strengthen the plastic hinge area of precast columns by using local prefabricated UHPC jackets. Three specimens were tested under reversed cyclic loading to evaluate the seismic performance of the precast column strengthened with local prefabricated UHPC jackets. The results show that the specimen with the proposed prefabricated UHPC jackets shifts the damaged areas away from the column-footing connection region and achieves comparative seismic performance to that of the monolithic reference specimen. The plastic hinge length of the column strengthened with a local prefabricated UHPC jacket can be estimated by the plastic hinge length models for monolithic concrete members.