Performance of Cellular Composite Floor Beams under Severe Fire Conditions

尽管目前大跨度复合地板系统很受欢迎，但目前的结构防火工程设计规范EC3/4第1.2部分和BS5950第8部分没有包含关于采用蜂窝钢梁的复合地板的防火性的规则或指导。本项目的目的是研究全尺寸复合蜂窝楼板梁在高温下的性能和破坏机制，包括弯曲和剪切的影响，单独和组合。当梁在火中加热时，重点还将放在检查由轴向约束引起的额外压缩力的发展和影响上，以引起周围结构的热膨胀。拟议的研究是基于在阿尔斯特的物理模型火灾试验方案，提供丰富的数据，这将大大提高对复合蜂窝钢梁在火灾中的行为的理解水平。这种方法将通过计算机建模与测试的结合得到扩展和加强，最初是为了验证和合理化行为，但会导致广泛的参数研究，旨在为这些构件开发一种设计方法。使用暴露在火灾中的钢CBs的复合地板的合理设计指南的可用性将使在目前不存在的合理和可靠的基础上计算防火要求成为可能，并将为英国顾问和制造商带来可能的全球出口机会。

Despite the current popularity of long-span composite flooring systems, the current structural fire engineering design codes EC3/4 Part 1.2 and BS5950 Part 8 do not contain rules or guidance on the fire resistance of composite floors employing cellular steel beams. The purpose of this project is to investigate the performance and failure mechanisms of full-scale composite cellular floor beams at elevated temperatures over a range of spans, including the influence of both flexure and shear, alone and in combination. Emphasis will also be placed on examining the development and influence of the additional compression forces caused by axial restraint to thermal expansion ensuing from the surrounding structure when a beam is heated in a fire. The proposed research is based on a programme of physical model fire tests at Ulster, to provide a wealth of data which will greatly enhance the level of understanding of behaviour of composite cellular steel beams in fire. This approach will be extended and enhanced by the integration of computer modelling with the testing, initially for validation and rationalisation of the behaviour, but leading to an extensive parametric study aimed at developing a design methodology for such members in fire. The availability of sound design guidance on composite floors using steel CBs exposed to fire would make it possible to calculate fire protection requirements on a rational and trustworthy basis which does not exist at present, and would lead to possible worldwide export opportunities for UK consultants and fabricators.