钢管混凝土柱耐火性能和抗火设计的特点

FIRE BEHAVIOR AND FIRE-RESISTANT DESIGN OF CONCRETE-FILLED STEEL TUBULAR COLUMNS

简要论述了按 ISO- 834和 GB 9978- 88规定的标准升温曲线升温作用下钢管混凝土柱耐火性能的特点 ,分析了影响钢管混凝土柱耐火极限的因素。说明了由于钢管和混凝土的共同工作且核心混凝土具有较好的吸热性能 ,从而使钢管混凝土柱具有较好的耐火性能。在进行钢管混凝土柱的抗火设计时 ,柱子外围只需进行适当的防火涂料保护 ,即可达到《高层民用建筑设计防火规范 (GB 5 0 0 4 5 - 95 )》对柱结构所要求的耐火极限。《高层民用建筑设计防火规范 (GB 5 0 0 4 5 - 95 )》

The behavior of concrete filled steel tubular columns under ISO 834 or GB 9978 88 standard fire curve is briefly introduced in the present paper.The influences of the changing strength of the materials, sectional dimensions, steel ratio, load eccentricity and slenderness ratio on the fire resistance are discussed. The results show that the composite columns have excellent behavior under fire and high fire resistance because of the interaction between the steel tube and its core concrete, as well as the heat absorption ability of the concrete core itself. The columns can satisfy the design fire resistance that are demanded by the code named GB 50045 95 Code for Fire Protection of High Rise Building with proper spraying material protection.the fire protection thickness determination methods for pure steel structure columns are unsuitable for the composite columns. The theoretical model in this paper were used to provide data on the necessary fire protection measures for the concrete filled steel tubular columns used in a high rise building, SEG Plaza in Shen zhen City, South China.In this case 78.6% coating can be saved on the column structures of the building.And the increase of the sectional dimensions of the columns is limited.So it has a good economic profit and architectural effect.