Guidelines for Enhancing Fire Endurance of High Strength Concrete Columns

摘要：美国是工业化国家中火灾损失最严重的国家之一，在消防科学和工程领域，结构火灾安全是最不发达的。火灾是建筑物可能面临的最严峻的环境条件之一，因此，为结构构件提供适当的消防安全措施是设计的一个重要方面。钢筋混凝土结构体系在高层建筑中的应用相当频繁，近年来，由于结构性能的提高，如高强和耐久性，高强混凝土的使用变得越来越普遍。本研究将从建立高强混凝土高温材料性能的本构关系入手。将开发一个计算机程序形式的数值模型，以跟踪高强混凝土柱在火灾暴露下的反应。采用基于理论传热学和力学原理的热/应变耦合平衡分析方法，对高强混凝土柱在火灾作用下的受力性能进行了估算。该模型将使用通过一系列耐火试验获得的试验数据进行验证，这些试验将在HSC柱上进行。验证后的数值模型将用于进行一系列参数研究，以确定影响高强混凝土柱耐火性能的各种因素。参数研究和试验的结果将被用来为高强混凝土柱的消防安全设计制定合理和经济有效的指导方针。

Abstract: The United States has one of the worst fire loss records in the industrialized world and within the area of fire science and engineering, structural fire safety is the least developed. Fire represents one of the most severe environmental conditions to which structures may be subjected, and hence, the provision of appropriate fire safety measures for structural members is an important aspect of design. Reinforced concrete structural systems are quite frequently used in high-rise buildings and in recent years, the use of high strength concrete (HSC) is becoming more popular due to the improvements in structural performance such as high-strength and durability. This research will start with the development of constitutive relationships for high temperature material properties of HSC. A numerical model, in the form of a computer program, will be developed for tracing the response of HSC columns under fire exposure. The behavior of an HSC column subjected to fire will be estimated using coupled heat transfer/strain equilibrium analysis based on theoretical heat transfer and mechanics principles. The model will be validated using test data obtained through a series of fire resistance experiments that will be conducted on HSC columns. The verified numerical model will be utilized to carryout a series of parametric studies to determine various factors that govern the fire resistance of HSC columns. Results from parametric studies and experiments will be used to develop rational and cost-effective guidelines for fire safety design of HSC columns.