Experimental study on the seismic behavior of RC columns with high axial compression ratios retrofitted by large rupture strain fiber-reinforced polymer. (15th February 2023)

• Record Type: Journal Article
• Authors: Ma, Chao; Gao, Hui; Li, Kai; Liao, Weizhang; Wang, Zuohu; Bai, Yulei
• Is Part Of: Engineering structures. Volume 277(2023)
• Publication Date: 2023-02-15
• Subjects: PET FRP retrofitting -- High axial compression -- Seismic test -- Failure mode -- Deformation capacity; 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.2022.115448
• Languages: English
• ISSNs: 0141-0296

Abstract

Highlights: 1. Seismic tests on the PET FRP retrofitting RC columns with high axial compression were conducted. 2. PET FRP retrofitting significantly changes the failure modes of the RC columns. 3. PET FRP retrofitting could improve the ductility of the RC columns under high axial compression loads. 4. Laterally wrapped scheme is more suitable for retrofitting RC columns. Abstract: Fiber-reinforced polymer (FRP) composites being utilized to retrofit reinforced concrete (RC) columns has been well documented. However, the axial compression load of the FRP retrofitting RC columns was relatively limited. Aiming to analyze the applicability of FRP retrofitting RC columns with higher axial compression loads, this paper presents an experimental study on the seismic performance of RC columns retrofitted by the Polyethylene Terephthalate (PET) FRP composites. A total of twelve 1/3 scale RC columns were fabricated, including four control specimens and eight PET FRP retrofitting columns with two retrofit schemes. All the columns were tested under combined high axial compression load and cyclic lateral displacement excursions, and the maximum axial compression ratio reaches 1.1. The seismic performance of RC columns retrofitted by PET FRP was analyzed detailedly from the failure mode, shear force and deformation capacity, energy dissipation and ductility. The test results showed that PET FRP retrofitting changed the failure mode of RC columns from brittle to more ductile. The post-peak strength degradation of the columns was more rapid with the increase of axial compression ratio, but the strength degradation of the PET FRP retrofitting columns was more gradual. PET FRP retrofitting significantly improved the ductility and lateral deformation capacity of the columns even under the high axial compression ratio. PET FRP retrofitting can be applied for the RC columns with serous demand of deformation capacity due to the lighter change of shear-loading capacity and stiffness. Contrastively, the improvement of the seismic capacity of the RC columns retrofitted by the laterally wrapped scheme is higher than that of the striped wrapped scheme. Conclusions from this study provide useful references for the seismic retrofitting of RC structures.