Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Effect of continuous spirals on uni-axial strength and ductility of CFST columns
Abstract Nowadays reinforced concrete (RC) columns are commonly adopted in tall building structures. One of its associated problems is that the transverse steel cannot confine the concrete cover and has limited effect on the ductility improvement, particularly of those made of high-strength concrete (HSC). Therefore, there is usually a maximum limit of concrete strength that can be used. To further push up this limit, concrete-filled-steel-tube (CFST) columns are advocated for its better performance contributed by the composite action. However, this composite action cannot be fully developed because of different dilation properties between steel tube and concrete, and very often de-bonding between the constitutive materials will occur initially. To overcome this problem, external confinement in the form of spirals is proposed to improve the interface bonding. In this paper, a total of 38 specimens were fabricated and tested under uni-axial compression. From the results, it can be concluded that the proposed spirals can improve the strength, initial stiffness, ductility and the interface bonding by restraining the lateral expansion of steel tube and core concrete. Lastly, an analytical model evaluating the ultimate strength of spiral-confined CFST columns is proposed and verified.
Highlights Proposed use of continuous spirals in CFST columns Significant uni-axial strength and ductility improvement verified by tests Theoretical model for predicting uni-axial strength of spiral-confined CFST columns developed Applicability of proposed model verified by comparing with available test results
Effect of continuous spirals on uni-axial strength and ductility of CFST columns
Abstract Nowadays reinforced concrete (RC) columns are commonly adopted in tall building structures. One of its associated problems is that the transverse steel cannot confine the concrete cover and has limited effect on the ductility improvement, particularly of those made of high-strength concrete (HSC). Therefore, there is usually a maximum limit of concrete strength that can be used. To further push up this limit, concrete-filled-steel-tube (CFST) columns are advocated for its better performance contributed by the composite action. However, this composite action cannot be fully developed because of different dilation properties between steel tube and concrete, and very often de-bonding between the constitutive materials will occur initially. To overcome this problem, external confinement in the form of spirals is proposed to improve the interface bonding. In this paper, a total of 38 specimens were fabricated and tested under uni-axial compression. From the results, it can be concluded that the proposed spirals can improve the strength, initial stiffness, ductility and the interface bonding by restraining the lateral expansion of steel tube and core concrete. Lastly, an analytical model evaluating the ultimate strength of spiral-confined CFST columns is proposed and verified.
Highlights Proposed use of continuous spirals in CFST columns Significant uni-axial strength and ductility improvement verified by tests Theoretical model for predicting uni-axial strength of spiral-confined CFST columns developed Applicability of proposed model verified by comparing with available test results
Effect of continuous spirals on uni-axial strength and ductility of CFST columns
Lai, M.H. (Autor:in) / Ho, J.C.M. (Autor:in)
Journal of Constructional Steel Research ; 104 ; 235-249
04.10.2014
15 pages
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
Effect of continuous spirals on uni-axial strength and ductility of CFST columns
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