预制混凝土外挂墙板气密性检测方法试验研究

Experimental Study on the Airtightness Testing Method for Prefabricated Concrete External Wall Panels

预制混凝土外挂墙板由于施工质量等原因导致的开裂会影响建筑节能,因此有必要对其气密性进行检测评价以及提出有针对性的气密性检测方法。8块预制混凝土夹心外挂墙板拼接成试件,对其水平接缝和垂直接缝内外两侧均采用密封胶进行密封,并在两道密封中间留置常压防水空腔。采用建筑围护结构试验检测设备,分别在150 Pa、240 Pa、300 Pa和400 Pa四组正负压差的作用下进行气密性试验。结果表明,压差小于300 Pa时,混凝土外挂墙板墙体单位面积空气渗透量随压差增加呈线性增加,建议标准检测方法采用压差为150 Pa进行气密性试验,以10 Pa压力差作用下的单位面积空气渗透量作为气密性分级评判指标,并按此指标提出预制混凝土外挂墙板墙体的气密性分级标准。

Due to construction quality and other reasons,external wall panels of prefabricated concrete may crack and affect building energy efficiency.It is necessary to test and evaluate their airtightness and propose a method for airtightness testing.Eight prefabricated concrete sandwich wall panels were spliced together to form specimens.The horizontal and vertical joints of the specimens were sealed with sealant on both sides,and a normal pressure waterproof cavity was left in the middle of the two seals.Building envelope structure testing equipment was used to conduct airtightness tests under four sets of positive and negative pressure differences of 150 Pa,240 Pa,300 Pa,and 400 Pa.The results show that when the pressure difference is less than 300 Pa,the air permeability per unit area of concrete external wall panels increases linearly with the increase of pressure difference.It is recommended to use a standard testing method of air tightness test with a pressure difference of 150 Pa,and use the air permeability per unit area under the action of a pressure difference of 10 Pa as its air tightness grading evaluation index.Based on this index,a grading standard for the air tightness of prefabricated concrete external wall panels is proposed.