面漆对膨胀型防火涂层隔热性能的影响

摘要

A series of fire tests were carried out on intumescent coating protected steel plates both with and without top coating.The expansion ratio and effective thermal conductivity of intumescent coatings with and without top coating were compared.The results show that top coating reduces the expansion ratio of intumescent coating by around 30 ％ of the final thickness.The effective thermal conductivity is obtained as the average thermal conductivity of intumescent coating within the steel temperature range of 400-600 ℃,and can be used to present the insulating properties of intumescent coating with top coating.The proposed effective thermal conductivity can be expressed in linear relationship with the dry film thickness(DFT) of intumescent coatings with and without top coating.The effective thermal conductivity of intumescent coatings with top coating is larger than that without top coating by 3 0 ％-7 0 ％ under the same DFT.%分别对有无面漆的膨胀型防火涂层保护的钢板试件进行了火灾试验,并对有无面漆的膨胀型防火涂层的膨胀率和等效导热系数进行了对比分析.将钢构件温度为400～600℃时涂层导热系数的平均值作为等效导热系数,并用之来评价有无面漆的膨胀型防火涂层的隔热性能.结果表明:面漆使膨胀型防火涂层的膨胀率降低了30％左右;无论有无面漆,膨胀型防火涂层的等效导热系数都与涂层干膜厚度呈线性关系,有面漆的膨胀型防火涂层等效导热系数比相同厚度的无面漆膨胀型防火涂层等效导热系数增大了30％～70％.