Experimental and numerical investigations of the composite behaviour in concrete-filled tubular columns with massive steel core at high temperatures
Journal of Structural Fire Engineering
ISSN: 2040-2317
Article publication date: 31 August 2017
Issue publication date: 17 May 2018
Abstract
Purpose
This paper deals with experimental and numerical investigations of the composite behaviour within concrete-filled tubular columns with embedded massive steel core (CFTES columns). As the inner profile provides the main load-bearing capacity, the load introduction and transfer is of particular interest for the structural detailing of CFTES columns. Currently, no specific design regulations are available – neither for room temperature nor fire design. The presented investigations provide a basis for design recommendations and numerical approaches on reliable shear stresses.
Design/methodology/approach
Three series of push-out tests at room temperature and high temperatures are analysed in terms of ultimate shear strength, bond strength and shear strength-displacement-curve shape. The test parameters involve the steel core diameter and concrete cover, applying normal strength steel and concrete. Furthermore, a three-dimensional finite element model of the push-out tests is set up in Abaqus. The model implies temperature-dependent contact properties derived from the experimental tests using the cohesive behaviour method.
Findings
The test data reveal a distinctive reduction in both ultimate shear and bond strength for high temperatures. For high temperatures, the thermal expansion coefficients dominate the composite behaviour. Using the 3D numerical model and applying a temperature-dependent joint stiffness, maximum shear stress criterion and damage evolution, the observed composite behaviour can be described in a realistic manner.
Originality/value
The presented experimental investigations are unique, both concerning the investigated column type and performing push-out tests at high temperatures. For the first time, a temperature-dependent reduction of capable shear stresses is identified, which is crucial for the design of structural components.
Keywords
Acknowledgements
The presented work is part of the European RFCS-research project FRISCC (“Fire resistance of innovative and slender concrete filled tubular composite columns”) and was kindly funded by the European Commission (Grant No. RFSR-CT-2012-00025).
Citation
Schaumann, P. and Kleibömer, I. (2018), "Experimental and numerical investigations of the composite behaviour in concrete-filled tubular columns with massive steel core at high temperatures", Journal of Structural Fire Engineering, Vol. 9 No. 2, pp. 147-160. https://doi.org/10.1108/JSFE-01-2017-0010
Publisher
:Emerald Publishing Limited
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