Experimental and Numerical Study on the Compression Behavior of Square Concrete-Filled Steel Tube Stub Columns with Steel Fiber-Reinforced High-Strength Concrete

• Published in: International Journal of Polymer Science Vol. 2018; no. 2018; pp. 1 - 13
• Main Authors: Choi, Chang Sik, Chung, Joo-Hong, Choi, Hyun-Ki, Bae, Baek-Il, Jung, Hyung-Suk, Choi, Yun-Cheul
• Format: Journal Article
• Language: English
• Published: Cairo, Egypt Hindawi Publishing Corporation 01.01.2018; Hindawi; John Wiley & Sons, Inc; Wiley
• Subjects: Analysis; Building codes; Building materials; Civil engineering; Composite structures; Compressive strength; Computer simulation; Concrete; Confining; Construction; Construction materials; Design parameters; Earthquakes; Failure load; Feasibility studies; Fiber reinforced concretes; Fiber reinforcement; Finite element method; Green buildings; High strength concretes; High strength steel; Material properties; Mechanical properties; Reinforced concrete; Seismic engineering; Steel columns; Steel fiber reinforced concretes; Steel tubes; Stress-strain curves; Stress-strain relationships; Structural design; Thickness ratio; Yield point; Yield strength; Yield stress
• ISSN: 1687-9422; 1687-9430; 1687-9430
• DOI: 10.1155/2018/2385725

This study was conducted to evaluate the applicability of concrete-filled steel tube (CFT) columns made from high-performance construction materials. KBC2016, South Korea’s current building code, limits the maximum compressive strength of concrete at 70 MPa and the maximum yield strength of steel at 650 MPa. Similar restrictions to material properties are imposed on major composite structural design parameters in other countries worldwide. With the recent acceleration of the pace of development in the field of material technology, the compressive strength of commercial concrete has been greatly improved and the problem of low tensile strength, known to be the major limitation of concrete, is being successfully addressed by adding fiber reinforcement to concrete. Therefore, the focus of this study was to experimentally determine the strength and ductility enhancement effects, which depend on material composition. To this end, we performed concentric axial loading tests on CFT stub columns made from steel with a yield strength of 800 MPa and steel fiber-reinforced high-strength concrete. By measuring the strain at the yield point of CFT steel during the test, we could determine whether steel yields earlier than ultimate failure load of the member, which is a key design concept of composite structures. The analysis results revealed that the yield point of steel preceded that of concrete on the stress-strain curve by the concurrent action of the strain increase at the maximum strength, attributable to the high compressive strength and steel fiber reinforcement, and the strain increase induced by the confining stress of the steel tube. Additionally, we performed parametric study using ABAQUS to establish the broad applications of CFT using high-performance materials, with the width-to-thickness ratio as the main parameter. Parametric study was undertaken as experimental investigation was not feasible, and we reviewed the criteria for limiting the width-to-thickness ratio as specified in the current building code.