火灾中不同材料对钢筋混凝土构件受力性能的影响

从材料性能的角度分析，不同材料对钢筋混凝土结构构件的影响机理与影响程度是不同的。钢材的影响主要与力学性能有关；混凝土的影响既与力学性能有关，也与热工性能有关；不可燃的面层主要与热工性能有关，而可燃面层可以加大火灾的危险性，不可燃面层是一层阻隔层，火灾时可以阻止热量向混凝土内部传播，因此混凝土构件火灾时的安全可靠性可以得到改善和提高。对于可以燃烧的装饰层而言，则会产生热荷载，结构构件在火灾时的损伤或破坏会加重。本利用欧洲规范采用的火灾时室内的温度－时间曲线、高温作用下混凝土和钢筋的本构关系，以及钢筋混凝土结构非线性分析方法，研究和分析了火灾时钢筋混凝土构件载面的温度分布和承载能力，并根据分析计算结果讨论了影响混凝土结构火灾安全性的因素。

Effect of Different Materials on the Behavior of Concrete Memb ers Under Fire

From the point of view of their performance in fire,for steel, the mechanical properties related to behavior in tension at elevatedtemperature are of principle interest; for concrete, the mechanical propertiesand thermal properties are of equal interest; for non-burnable coatings, only t he thermal properties are of interest; and for burnable coatings, it is severityof fire. Non-burnable coatings can prevent fire heat to penetrate to their inn er structural members, thus the fire safety of concrete structures can be improv ed by this kind of coatings. On the other hand burnable coatings can produce add itional heat during fire. As a result, more damage would be induced to concretestructures with burnable decorative materials if fire were encountered. The Euro -Code indoor temperature-time relationship under fire condition, constitutiverelationship of concrete and steel at elevated temperature and concrete nonlinea r analysis approach are employed, and the distribution of temperature within thesection of concrete members and the load carrying capacity are investigated. Ba sed on the analysis results, factors related to the fire safety of concrete stru ctures exposure to fire have been discussed.