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压型钢板组合楼板防火.doc

发布:2017-05-24约6.15千字共9页下载文档
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压型钢板—组合楼板耐火试验和破坏模式的探讨 中冶集团建筑研究总院 白力更 马德志 摘要: 本文试验测试了在标准升温条件下,闭口式压型钢板不同部位的升温情况。试验表明被 混凝土包裹的部分升温要比直接受火面慢,但由于热传导,升温122min时被混凝土包裹的 部分最低温度也超过了 6000C。试验还表明无论是火灾的前期还是后期,板的混凝土厚度 都是影响组合楼板耐火性能的重要参数。文章分析了高温状态下组合楼板的试验现象,定 性地分析了各影响参数,并探讨了组合楼板在耐火极限状态下的破坏模式。由于影响组合 楼板耐火性能的参数多而复杂,许多影响参数并未被一致确认,在此情况下,文章建议防 火设计应必须保证一定的混凝土厚度,确保火灾下组合楼板的安全。 关键词:组合楼板、耐火试验、破坏模式 FIREPROOFING TEST AND DISTRUCTIVE MODE OF COLD-FORMED STEEL DECK –COMPOSITE SLAB Abstract:In this paper, we test the increase of temperature on different parts of cold-formed steel deck with closed rib under the standard condition. The results indicate that the increase of the temperature on the part enwrapped in concrete is slower than that straightly fired, but because heat conduction, the lowest temperature of this part also can exceed 600℃ after fired for 122 minutes. The results prove that the thickness of concrete is one of the important factors that influence the fireproofing properties of the composite slab during the period of both prophase and anaphase when fire disaster happening. The paper analyzed the phenomenon of composite slab under high temperature condition and qualitative analyzed the factors that influence fireproofing properties and also discussed the destructive mode of composite slab under critical fireproofing condition. The factors that influence fireproofing properties can not be confirmed because the factors are too many and complicate, under this condition, the paper propose that we should ensure the safety of composite slab during fire disaster through a certain thickness of concrete. Keywords:composite slab fireproofing test destrutive mode 行业标准《钢—混凝土组合楼盖结构设计与施工规程》(YB9238-92)[1]是以压型钢板替 代或部分替代钢筋为基础编制的,但在钢-混凝土组合楼板引进我国的初期,实际工程大多 是以压型钢板作为永久模板使用,楼板按普通钢筋混凝土计算,因为此类组合楼板与普通钢 筋混凝土楼板一样,不存在特殊的防火问题,所以该问题也并未得到重视。近年来,以压型 钢板替代或部分替代正弯矩钢筋的设计理念逐步被设计人员所接受,组合楼板不配正弯矩钢 筋的组合楼板越来越多。在组合楼板设计时,其板跨往往由施工时的支撑檩距所决定,其跨 度一般较小,组合楼板使用阶段的强度和变形比较容易保证,而此时压型钢板暴露在外,因 此防火和防腐成为组合楼板设计的关键。组合楼板的耐火性能研究在我国起步较晚,近年来 也做了一些研究[2][4][4],但总体来讲我国在此方面的研究,特别是
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