| Title |
Evaluation of Axial Behavior of Strengthened Columns according to Different Peripheral Closed Hoops in Jacket Section |
| Authors |
Hwang, Yong-Ha ; Yang, Keun-Hyeok ; Sim, Jae-Il ; Choi, Yong-Soo |
| DOI |
https://doi.org/10.5659/JAIK_SC.2019.35.7.139 |
| Keywords |
Column; Section Enlargement Strengthening; Peripheral Closed Hoops; Ductility |
| Abstract |
This study examined the effect of various arrangement methods for forming peripheral closed hoops in the jacket section on the axial
behavior of section enlargement strengthening columns. Four types of peripheral closed hoops arranged in the jacket section were prepared as
follows: 1) Closed connection of prefabricated bar units (column P); 2) V-clip installation across the overlapped legs of channel-type bars
(column V); 3) Use of glass fiber mesh for an alternative of steel bars (column F); and 4) combination of prefabricated bar units and glass
fiber mesh (column PF). The V-clip is designed to form the closed hoops in the jacket section using the overlapped channel-type bars,
preventing the opening of the channel bar legs. The glass fiber mesh is to examine the feasibility to apply for closed hoops in the jacket
section as an alternative for steel bars, considering the easy construction. In the jacket section of all the strengthened columns, V-ties were
arranged for supplementary ties, avoiding the interruption of the existing column. The axial stiffness and strength of the strengthened columns
were insignificantly affected by the arrangement methods of closed hoops in the jacket section. The axial ductility ratio of the strengthened
columns P, V, and PF was enhanced more than twice of that measured in the non-seismic existing column. However, the column F exhibited
a lower ductility than the other strengthened columns because of the fracture of the mesh at the ultimate strength of the column. The V-clip
approach was favorable to enhance the ductility of the strengthened column, preventing the opening of the legs of channel-type bars. |