Abstract This paper presents an experimental study of the behavior of intumescent coatings exposed to localized fires. The main objective is to assess the extent to which thermal properties of intumescent coatings obtained under uniform heating can be applied for localized fire exposures. The experiments used two types of specimens representing protected steel beams and columns. Localized pool fires were placed underneath horizontal specimens or beside vertical specimens. Solvent-based and waterborne intumescent coatings were applied to the specimens. Measurements were made of temperatures of the steel specimens and the adjacent gas phase, as was coating expanded thicknesses at several locations. Depending on their location relative to fires, the intumescent coatings were variably unreacted, melted, partially expanded, or fully expanded (corresponding to steel temperatures of about less than 100 °C, 100–300 °C, 300–400 °C, and above 400 °C, respectively). The appearances and expansion ratios for various regions of coatings under localized fires were consistent with those under uniform heating from previously obtained furnace test results. Steel temperatures of the specimens were calculated using thermal conductivities of coatings derived from furnace tests, and were found to agree reasonably with the experimental results, thus indicating that it may be feasible to apply thermal conductivities derived from furnace tests to predict steel temperatures under localized heating scenarios.

中文翻译：

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局部火灾下膨胀型涂料行为的实验研究

摘要 本文介绍了膨胀型涂料暴露于局部火灾中的行为的实验研究。主要目的是评估在均匀加热下获得的膨胀型涂层的热性能可应用于局部火灾暴露的程度。实验使用了两种代表受保护钢梁和柱的试样。局部池火放置在水平试样下方或垂直试样旁边。将溶剂型和水性膨胀型涂料应用于样品。测量钢试样和相邻气相的温度，以及涂层在几个位置的膨胀厚度。根据它们相对于火灾的位置，膨胀涂层不同程度地未反应、熔化、部分膨胀、或完全膨胀（分别对应于约低于 100 °C、100–300 °C、300–400 °C 和高于 400 °C 的钢温度）。局部火灾下涂层各区域的外观和膨胀率与先前获得的炉试验结果均匀加热下的外观和膨胀率一致。试样的钢温是用熔炉试验得出的涂层热导率计算得出的，结果与实验结果相吻合，表明应用熔炉试验得出的热导率来预测局部加热下钢的温度是可行的场景。局部火灾下涂层各区域的外观和膨胀率与先前获得的炉试验结果均匀加热下的外观和膨胀率一致。试样的钢温是用熔炉试验得出的涂层热导率计算得出的，结果与实验结果相吻合，表明应用熔炉试验得出的热导率来预测局部加热下钢的温度是可行的场景。局部火灾下涂层各区域的外观和膨胀率与先前获得的炉试验结果均匀加热下的外观和膨胀率一致。试样的钢温是用熔炉试验得出的涂层热导率计算得出的，结果与实验结果相吻合，表明应用熔炉试验得出的热导率来预测局部加热下钢的温度是可行的场景。