Cyclic tests of precast post-tensioned concrete filled steel tubular (PCFT) columns with internal energy-dissipating bars. (15th February 2021)

• Record Type: Journal Article
• Authors: Shen, Yu; Liu, Xueshan; Li, Yongxing; Li, Jianzhong
• Is Part Of: Engineering structures. Volume 229(2021)
• Publication Date: 2021-02-15
• Subjects: Bridge column -- Concrete filled steel tubular -- Post-tensioned -- Cyclic tests -- Seismic behavior -- Energy dissipation -- Self-centering; Structural engineering -- Periodicals; Structural analysis (Engineering) -- Periodicals; Construction, Technique de la -- Périodiques; Génie parasismique -- Périodiques; Pression du vent -- Périodiques; Earthquake engineering; Structural engineering; Wind-pressure; Periodicals; 624.105
• DOI: 10.1016/j.engstruct.2020.111651
• Languages: English
• ISSNs: 0141-0296

Abstract

Highlights: Six PCFT columns with internal energy dissipation bars were cyclically tested. UHPC bedding layer and steel tube can ensure the larger ductility of PCFT columns. The effects of initial PT force and ED bars on PCFT columns are identified. The PCFT column is a minimal-damage precast structure with superior seismic behavior. Abstract: In this paper, a promising construction option, which combines the concrete filled steel tubular (CFT) column and the self-centering rocking system, is introduced and its seismic behavior is experimentally investigated. In this hybrid system, named as post-tensioned concrete filled steel tubular (PCFT) column, the unbonded post-tensioned (PT) tendons and energy dissipation (ED) devices are employed to provide recentering and ED properties, respectively. The steel tube acts as a protective jacket, stay-in-place formwork, and transverse reinforcement. Six PCFT columns with different amounts of initial PT force and ED bars were tested. All columns failed due to the fracture of ED bars and the crushing of mortar bed which though was cast from ultra-high performance concrete (UHPC). The column shafts of specimens suffered little damage after testing. The amount of ED bars greatly affected the self-centering capacity and ED capacity of the PCFT columns when the ratio of ED bars was less than 1.2%. Beyond this ratio, its effect was negligible. Additionally, increasing initial PT force made only a little difference to the load-carrying capacity but significantly enhanced the self-centering capacity of the column.