Effect of thermal contact resistance on cross-sectional temperature distributions of composite structural members during fire exposure

Structural Fire resistant behaviour and design is one of key technologies in the design of constructions and is issue to life safety and property insurance in fire conditions. To composite structural elements in the forms of concrete-filled steel tubes, steel-decked composite floor slabs and slim floor beams, the temperature distribution analysis and the subsequent fire resistant behaviour research are particular for their relatively complex of composition of cross sections. Many models to predict the response of composite structures in fire have been developed. One of the major drawbacks for these models is ignoring the effect of thermal contact resistance at the steel-concrete interfaces, and the analysis results can not reflect the feature of poly-gradient of temperature distribution and predictions of temperature are deviated from those of true values. Using the collected models considering the contact thermal resistance and the research results of the authors, the method that how to consider the thermal contact resistance was improved and the influence of thermal contact resistance on the temperatures of composite cross sections was analyzed. The work may provide reference and basis for the further research on the fire resistance behaviour of composite structures.