在分析建筑外覆面系统火灾蔓延特点的基础上,重点从外覆面系统建筑材料及构件燃烧性能的评价和外覆面系统整体防火性能的评价两个方面综合比较了欧美建筑外覆面系统防火性能评价体系,根据外覆面系统建筑材料及构件的燃烧性能以及是否存在空腔结构,提出了外覆面系统防火性能分级方法及其相应的防火性能评价要求,建议在进一步发展完善我国建筑材料及构件的不燃-难燃-可燃量化评价方法的同时,尽快建立外覆面系统整体防火性能评价方法以及确保测试构件与建筑外覆面系统实际状况相一致的机制,并把外覆面系统的防火性能要求纳入到建筑整体消防安全问题中统筹考虑,在国家强制性通用消防技术规范中明确提出外覆面系统防火性能的原则性要求及具体测试标准,进一步强化建筑行业自身在确保建筑外覆面系统防火性能方面的责任。

The mechanisms of fire spread by way of the external cladding systems for buildings are discussed. And the standard test methods for fire performance of the external cladding systems for buildings in Europe and America are analyzed. The fire performance classification of external cladding systems and the corresponding fire test requirements are proposed based on the burning characteristics of building materials, construction products and building elements of the external cladding systems and for cases with cavities existing in the external cladding systems. Suggestions are made for developing a fire performance evaluation system for the external cladding systems for buildings in China. The evaluations of the burning characteristics of building materials, construction products and building elements of the external cladding systems are important for keeping the external cladding systems intact without significant fire spread or system collapse. The provisions to limit the susceptibility of the external surface of walls to ignition and to fire spread should be adopted if there are combustible materials and/or cavities in the external cladding systems of buildings. Therefore, the full scale tests for integrated fire performance of the external cladding systems for buildings are necessary, which involve tests for fire resistance, fire spread, and so on. It is urgent to develop the evaluation methods for the integrated fire performance of the external cladding systems and to determine the ensuring mechanism for test specimen to be representative of a facade used in practice, both in constructions and products in China. At the same time, it is necessary to develop a quantitative system of non-combustible, limited-combustible and combustible for building materials, construction products and building elements of the external cladding systems. The fire performance requirements should be established for external cladding systems of buildings in the whole fire safety considerations of buildings. The fundamental and fire test standards should be put forwards clearly in the national general codes for fire techniques. The construction industry should take the responsibility in guaranteeing the fire performance and construction quality of the external cladding systems for buildings.