Load-carrying capacity of circular recycled aggregate concrete-filled steel tubular stub columns under axial compression: Reliability analysis and design factor calibration. (1st May 2023)

• Record Type: Journal Article
• Authors: Chen, Wenguang; Xu, Jinjun; Li, Zhipeng; Huang, Xinliang; Wu, Yuntian
• Is Part Of: Journal of building engineering. Volume 66(2023)
• Publication Date: 2023-05-01
• Subjects: Recycled aggregate concrete -- Concrete filled steel tubes -- Axial compression -- Load-carrying capacity -- Reliability analysis -- Calibration; Building -- Periodicals; 690.05
• DOI: 10.1016/j.jobe.2023.105935
• Languages: English
• ISSNs: 2352-7102

Abstract

Abstract: It has been well-reported that using steel tubes to confine recycled aggregate concrete (RAC) is an effective solution to strengthen the imperfection of RAC, namely RAC-filled steel tubes (RAC-FST). Yet to date available design codes applicable to the axial compressive behavior of RAC-FST stub columns are still limited, and very scarce studies have concentrated on investigating the structural safety. This paper presents a full-scope reliability-based design analysis for the load-carrying capacity of circular RAC-FST stub columns under axial compression. First, the performances of several code-based models were evaluated in terms of model uncertainty based on a reliable experimental database that comprises 94 circular RAC-FST stub columns, respectively. Then, the statistical characteristics for characteristic compressive strength of RAC were specially identified, and other uncertainties associated with steel strength, geometrical configurations, and loads were taken from available publications. Subsequently, the reliability of circular RAC-FST stub columns designed using existing design factors in current normal concrete filled steel tubes (CFST) codes was investigated in conjunction with Monte Carlo simulation (MCS) technique. Results indicated that in order to achieve the reasonable design of circular RAC-FST stub columns, existing design factors need to be calibrated. Accordingly, a combined partial factor directly reducing the whole resistance of composite cross-section was proposed, and the corresponding recommendations were provided based on the target reliability index-oriented calibration process. Highlights: Performances of several code-based models were evaluated in terms of model uncertainty. Statistical characteristics for characteristic compressive strength of RAC were identified. Reliability of RAC-FST columns designed using existing design factors in CFST codes was investigated. A combined partial factor directly reducing the whole resistance of composite cross-section was proposed.