Civil Engineering and Architecture Vol. 9(7), pp. 2397 - 2415
DOI: 10.13189/cea.2021.090726
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Experimental Investigation on Concrete Filled Steel Tube Columns under Concentric and Eccentric Loading

Panya Klongaksornkul , Kitjapat Phuvoravan ^*
Department of Civil Engineering, Kasetsart University, Bangkok, Thailand

ABSTRACT

Modern construction projects such as skyscrapers, bridge with a large span, residential structures, towers for transmission, warehouses and other industrial structures have all incorporated concrete-filled steel tube (CFST) columns. Fire resistance, excellent ductility and high bearing capacity are all the advantages of CFST columns. Among the different shapes of CFST columns, uses of rectangular and square CFST columns are becoming more favored in modern construction projects for their simple beam-to-column connections design. This study tested 10 concentrically loaded CFST columns and 8 eccentrically loaded CFST columns. One of the most effective techniques to delay local buckling and enhance the ultimate strength of the CFST columns is to use longitudinal inner stiffeners on these steel tubes. Cold-formed steel tube sections are vulnerable due to local buckling; however, a concrete core is able to restrict such early local buckling in the cold-formed steel tube. The test specimens consisted of unstiffened sections and longitudinal inner-stiffened sections. In total, the experimental program tested 18 CFST stub columns with both compact and slender sections, without longitudinal stiffener, with 2 longitudinal inner stiffeners and with 4 longitudinal stiffeners. The test strengths have been as compared with predictions based on the existing design code AISC 360-16 for calculating the ultimate capacities of the CFST stub columns subjected to both concentric and eccentric loading. The focus was mainly on the effect of vertical stiffener square concrete-filled steel tubes on the overall concentric and eccentric compression capacity. The results identified that the longitudinal inner stiffeners had a significant impact on the ultimate strength, deformability and mode of failure in the CFST stub columns. To prevent local buckling of such steel tube, a longitudinal inner stiffener could be applied. In addition, the compression capacity was increased by 12–13.5%.

KEYWORDS
Concrete-Filled Steel Tube, Longitudinal Inner Stiffened Sections, Ultimate Strength

Cite This Paper in IEEE or APA Citation Styles
(a). IEEE Format:
[1] Panya Klongaksornkul , Kitjapat Phuvoravan , "Experimental Investigation on Concrete Filled Steel Tube Columns under Concentric and Eccentric Loading," Civil Engineering and Architecture, Vol. 9, No. 7, pp. 2397 - 2415, 2021. DOI: 10.13189/cea.2021.090726.

(b). APA Format:
Panya Klongaksornkul , Kitjapat Phuvoravan (2021). Experimental Investigation on Concrete Filled Steel Tube Columns under Concentric and Eccentric Loading. Civil Engineering and Architecture, 9(7), 2397 - 2415. DOI: 10.13189/cea.2021.090726.