THE BUCKLING OF SLENDER CONCRETE AND （纤细的混凝土和屈曲）.pdf

THE BUCKLING OF SLENDER CONCRETE AND CONCRETE- FILLED COLUMNS IN FIRE Shan-Shan Huang*, Dorothy Hodgkin Scholar, University of Sheffield, United Kingdom Ian Burgess, Professor, University of Sheffield, United Kingdom Zhao-Hui Huang, Lecturer, University of Sheffield, United Kingdom Roger Plank, Professor, University of Sheffield, United Kingdom Keywords: Transient Thermal Strain, Buckling, Slender Concrete Columns, Concrete-Filled Columns, Fire. ABSTRACT Pre-compressed concrete has been observed to acquire a large amount of irreversible strain (called Transient Thermal Strain) when it is heated. This effect appears not to occur when heating precedes the application of compressive stress. The objective of the research reported in this paper is to assess how this phenomenon affects the buckling resistance of slender concrete and concrete-filled hollow-section columns in fire. Preliminary analyses pre3sented in the paper lead to the conclusion that TTS does have an adverse effect on the buckling temperatures of uniformly heated slender concrete columns. 1. INTRODUCTION Concrete-filled steel hollow-section columns have become increasingly popular recently, especially in the construction of tall buildings. They have a much-enhanced load-bearing capacity at ambient temperature compared to conventional reinforced concrete columns and steel hollow-section columns. This enhanced load-bearing capacity mainly results from the ‘composite action’ between the two materials. The steel tube provides effective confinement to the concrete infill; in turn the concrete infill prevents the steel t