Numerical investigation and design of UHPC-encased CFST stub columns under axial compression
Document Type
Article
Publication Date
3-1-2024
Abstract
Reinforced ultra-high-performance concrete (RUHPC)-encased concrete-filled steel tubular (CFST) columns in composite construction have exceptional fire and corrosion resistance, superior load-bearing capacity, and enhanced ductility compared to standalone RUHPC and CFST columns. However, research on their behavior is limited. This paper presents a 3D finite element (FE) simulation model for accurately predicting the behavior of axially loaded RUHPC-encased CFST short columns. The model accounts for the effects of the concrete confinement provided by the steel reinforcement and circular steel tube. The existing experimental data is used to validate the FE model. The validated model is then utilized to investigate the performance of RUHPC-encased CFST columns with various geometric and material properties. The range analysis technique is applied to an orthogonal design to assess the relative significance of the factors affecting the structural behavior. The findings reveal that RUHPC-encased CFST columns have high ultimate strength and ductility. The range analysis identifies the importance order of parameters as: the compressive strength of UHPC, the steel fiber concentration, tube diameter, stirrup spacing, tube thickness, and confined concrete's compressive strength. Lastly, a simplified design model is developed to estimate the compressive capacity of RUHPC-encased CFST stub columns, providing accurate results that are verified by tests and numerical analysis.
Keywords
Composite columns, Ultra-high-performance concrete, Finite element modeling
Divisions
sch_civ
Funders
National Natural Science Foundation of China (NSFC) (52278144); (52221002),Fundamental Research Funds for the Central Universities (2022CDJQY- 009)
Publication Title
Engineering Structures
Volume
302
Publisher
Elsevier
Publisher Location
125 London Wall, London, ENGLAND