Effect of fire on concrete and concrete structures

作者：Gabriel Alexander Khoury · 发表于：Progress in Structural Engineering and Materials · 年份：2000 · DOI：10.1002/pse.51 · 被引用次数：804 · 研究领域：Fire effects on concrete materials、Fire dynamics and safety research、Engineering and Material Science Research

Abstract The behaviour of concrete in fire depends on its mix proportions and constituents and is determined by complex physicochemical transformations during heating. Normal‐strength concretes and high‐performance concretes microstructurally follow similar trends when heated, but ultra‐high‐performance concrete behaves differently. A key property unique to concrete amongst structural materials is transient creep. Any structural analysis of heated concrete that ignores transient creep will yield erroneous results, particularly for columns exposed to fire. Failure of structural concrete in fire varies according to the nature of the fire; the loading system and the type of structure. Failure could occur from loss of bending or tensile strength; loss of bond strength; loss of shear or torsional strength; loss of compressive strength; and spalling of the concrete. The structural element should, therefore, be designed to fulfil its separating and/or load‐bearing function without failure for the required period of time in a given fire scenario. Design for fire resistance aims to ensure overall dimensions of the section of an element sufficient to keep the heat transfer through this element within acceptable limits, and an average concrete cover to the reinforcement sufficient to keep the temperature of the reinforcement below critical values long enough for the required fire resistance period to be attained. The prediction of spalling – hitherto an imprecise empirical exercise – is...