【摘要】 本文从平面框架入手,通过对三榀相同尺寸和相同持荷情况下的单层单跨矿渣高性能混凝土框架结构的火灾试验,研究了高性能混凝土框架结构的火灾反应和抗火性能特点。通过对火灾中框架温度场、位移反应等的分析以及火灾后框架表面裂缝、颜色和残余变形等的对比,分析了不同混凝土强度等级、有无外掺聚丙稀纤维对矿渣高性能混凝土框架结构火灾反应和抗火性能的影响。研究表明,在800℃左右火灾作用下,矿渣高性能混凝土框架结构具有良好的抗火性能,高性能混凝土的强度等级提高对结构火灾破坏前承受变形的能力是有益的;由火灾引起的构件轴向变形和内力重分布导致在梁柱节点存在较大的内力;框架作为超静定结构,梁柱在火灾中的刚度退化情形不一致,对整体结构的抗火性能明显不利;而聚丙稀纤维的掺加增加了火灾中混凝土温度裂缝的产生,但提高了降温时结构的变形恢复能力。更多还原

【Abstract】 In this paper, three single span and single storey HPC BFS (high performance concrete with blast furnace slag) frames with the same size and loading condition were tested under a fire.In consideation of the effects of concrete strength grade and PPF(polypropylene fiber),the fire response and fire resistance of the frames were investigated in the aspects of temperature field,displacement and post fire appearance,etc.It was concluded from this investigation that the frames behaved well when exposed to a fire of 800℃,the deformation capacity of frames increased with the improvement of the strength grade, the beam column joint of frames bore more moments due to axial deformation of members and redistrbution of internal forces of frames under fire,the different stiffness degradation between beam and column reduced the fire resistance behavior of frames,and PPF resulted in more temperature cracks under fire but brought a good deformation recovered capacity during cooling.更多还原