基于高性能耐火钢材的组合楼盖结构体系抗火性能研究

压型钢板钢-混凝土组合楼盖是多高层建筑的关键构件，其抗火性能是影响结构整体安全性的关键要素。普通压型钢板钢-混凝士组合楼盖的自身抗火性能难以满足结构抗灾安全性要求，压型钢板主要用做施工阶段的模板，钢梁部分需要采用防火涂料或防火保护保证其火灾下的安全性，抗火保护层存在耐久性难以与主体结构等寿命，且维修困难并成本高的难题。新型耐火结构钢材的应用为提高组合楼盖抗火性能提供了新的途径，由被动防护变为主动抗火。目前国内外对耐火钢组合楼盖抗火性能的科学问题缺乏基础性研究，更无应用技术、设计方法和技术标准。本项目提出采用耐火钢构建新型钢-混凝土组合楼盖体系，系统研究新型组合楼盖在常温和火灾下的受力性能和破坏机理，建立耐火钢组合楼盖的抗火性能评价和设计方法，为耐火钢组合楼盖应用提供依据。本项目研究是高性能组合结构体系及其整体抗灾性能基本设计方法的创新，对提高建筑结构全寿命抗灾安全性具有重要学术意义和应用价值。

Profiled steel-concrete composite floor are the primary structural member in high-rise building, and its fire resistance is the dominant considerations in assessing the structural safety. The fire resistance of traditional composite beam and slab is provided by fire coating or insulation material, and the profiled steel deck is used as the formwork for in-situ casting concrete slab. However, the durability of fire protection may not be consistent with the structural members. Meanwhile the maintenance and rehabilitation of fire protection is expensive and difficult, and new solution is required. The high performance fire-resistant steel(HPFRS) with the properties of less strength reduction under elevated temperature has provided an innovative method for significantly improving the fire resistance of steel-concrete composite floor. Unfortunately, there is neither fundamental research being performed in applying HPFRS in composite beam and slab nor technology and specification available for assessing fire behavior of composite structure fabricated from HPFRS. This project proposes an innovative composite floor system with fire-resistant steel deck to improve the fire resistance of composite floor. The structural behavior of the new type composite floor under normal and elevated temperature will be extensively investigated, and the failure mode and fire resistance will be understood. The fundamental analysis and design method for assessing the fire resistance of the new type of composite floor will be provided to demonstrate the benefit of higher fire resistance of HPFRS. The project outcomes will also provide indispensable information for drafting specification relevant to composite beam fabricated from HPFRS. The project outcome will produce an innovative solution for fire safety of composite beam where the fire resistance can be provided by the structural member itself instead of fire protection, and will make a great contribution to the development of high performance structural system and its design theory, with the potential to increase the safety of building structures.