Structural Fire Engineering of Building Assemblies and Frames

Use of the temperature-dependent, thermophysical material properties, shape geometry, and fundamental heat transfer and structural principles, in combination with available fire test data, can enable several distinct levels of engineering/calculation methods of fire resistance. The simpler computational methods, such as those in ASCE/SFPE 29-99,1 are semi-empirically based on standard fire test results. They provide an efficient and generally conservative way to provide fire resistance ratings for members and assemblies that do not directly match listed assemblies to meet prescriptive code requirements. Higher order fire simulations and structural analyses can also be used as performance-based design alternatives to achieve a more accurate solution to overall fire safety. Substantial fire-induced damage is expected after a severe (fully developed or postflashover) fire exposure, not only to the building contents and finish but also to the structural elements. It is not uncommon for well-designed, ductile, and properly functioning fire-resistive framing systems to experience visible distortions, cracking, permanent damage, and deflections in floor, walls, or columns than can be on the order of 12 to 24 inches (300 to 600 mm), or more, without collapse. In the following sections, several computational approaches to the determination of the fire resistance of building construction are summarized, independent of any requirements of a particular building code or design standard. These can be considered generally applicable to any structural material. The specific provisions of the governing building code and design standard(s) for a given project must be consulted for any engineering applications