FIRE RESISTANCE OF HIGH-STRENGTH CONCRETE ENCASED STEEL COMPOSITE COLUMNS

Abstract

Concrete encased steel (CES) column is a type of concrete-steel composite column ideal for top-down and high-rise constructions. CES columns are superior in fire resistance due to the concrete cover acting as a fire protection layer for the embedded steel section. While several countries have come up with their design codes for the fire resistance design of CES columns, a review of these modern design codes reveals that they have at least one of the following limitations: (a) being inapplicable to CES columns made of high-strength materials; (b) generating unsafe predictions for the fire resistance of CES columns subject to eccentric loadings; (c) being overly conservative; (d) requiring advanced knowledge and complex numerical software that are not viable for practical structural design. Hence the aim of this study is to investigate the fire performance of CES columns made of high-strength materials and propose a design method that overcomes the aforementioned limitations of current design codes. This is achieved by a series of experimental, numerical and analytical studies.