Heat Transfer Evaluation Method for RC Members at Standard Fire Scenario

Abstract

This paper addresses the heat transfer evaluation problem in RC members at standard fire loads. Accidental fire events in building structures are common, in which structural RC members come often into contact with severe fire conditions that directly affect their stability and integrity against collapse. The code and standard practices do not provide any provisions for fire resistance rating evaluation and specify the fire resistance rating of RC members by acknowledging their applicability in terms of concrete cover provision. RC member failure appraisal in performance-based design and analysis is one of the significant concerns in the recent era which depends on appropriate heat transfer analysis. In transient heating boundary conditions with associated influencing material properties, i.e., thermal conductivity, specific heat carry capacity, and diffusivity for normal strength concrete (NSC) and high strength concrete (HSC) are completely different, which directly influence heat transfer behavior using heating mechanisms. Therefore, a finite difference method (FDM) based heat transfer evaluation method has been proposed for both NSC and HSC with consideration of thermally induced material properties and appropriate heating mechanisms. The proposed method prediction has been verified with the experimentally performed database and it is observed suitable to evaluate heat transfer in RC members made by NSC and HSC at exposure to the standard fire load.