特殊施工环境下渠道伸缩缝聚氨酯止水材料粘结性能的试验研究

发布时间：2018-06-07 07:21

  本文选题：聚氨酯止水材料 + 渠道伸缩缝　； 参考：《新疆农业大学》2016年硕士论文

【摘要】：聚氨酯密封胶作为水工伸缩缝止水材料得到广泛应用。但在特殊环境和条件下,因施工环境温度、伸缩缝界面潮湿或粘有污物等原因往往会降低聚氨酯止水材料的粘结性能。因此,针对聚氨酯止水材料施工中存在的问题,开展了特殊施工环境下渠道伸缩缝聚氨酯止水材料粘结性能的试验研究。通过试验研究得出以下结论:(1)双组份聚氨酯止水材料的粘结性能,在施工前混合搅拌工序中受搅拌时间和环境温度的影响较大。试验结果发现:双组份聚氨酯止水材料的粘结性能随搅拌时间的延长而提高;环境温度越低双组份聚氨酯止水材料的搅拌难度越大、施工越困难、搅拌均匀程度越差、粘结性能越差。当环境温度为15℃~25℃时,充分搅拌时间应≥5min,才能保证双组份聚氨酯止水材料具有足够的粘结强度;当环境温度为≤2℃时,即使充分搅拌时间达到10 min,也难以保证双组份聚氨酯止水材料的粘结强度和质量;低温环境下采用掺加柴油的方法虽然在一定程度上能够稀释双组份聚氨酯拌合物,便于搅拌、混合均匀,但施工后聚氨酯止水材料的粘结强度会显著降低。(2)混凝土伸缩缝界面粘有灰尘、干燥泥土、潮湿泥土、油污时会降低聚氨酯材料的粘结强度,降低程度分别为21.71%、16.82%、43.43%、33.15%。对于粘有灰尘界面,采用“涂刷界面剂”、“毛刷处理”、“毛刷处理+界面剂”和“吹风机”四种处理方式可以有效改善界面粘结性能,其中“毛刷处理5遍+界面剂”措施的效果最佳;对于粘有干燥泥土界面,采用“钢刷+吹风机+界面剂”、“钢刷+吹风机”两种方式可以有效改善界面粘结性能。(3)采用“涂刷界面剂”措施对粘有浮尘界面有明显效果,但对粘有泥土界面无效。(4)粘结界面潮湿会明显降低聚氨酯材料的粘结强度,降低程度主要取决于界面含水率,含水率越高,降低程度越大。界面含水率在2.074%~4.197%范围内,聚氨酯材料的粘结强度下降15.32%~28.76%。对于潮湿混凝土伸缩缝界面,施工前,在环境温度为≥20℃时采取自然晾晒5 h或对伸缩缝界面喷烤处理20遍可以降低界面含水率,提高聚氨酯材料的粘结强度。(5)养护环境对聚氨酯材料的粘结性能也产生影响。相同施工情况下,施工后在潮湿养护环境下的聚氨酯材料粘结性能比干燥养护环境明显下降。(6)聚氨酯材料粘结强度随干燥养护时间的延长而提高。聚氨酯材料在经过不同干燥养护时间后承担输水任务,聚氨酯材料的粘结性能会有所下降,下降程度随干燥养护时间的延长而减小。
[Abstract]:Polyurethane sealant is widely used as hydraulic expansion joint watertight material. However, under special environment and conditions, the adhesive properties of polyurethane watertight materials are often reduced due to the temperature of construction environment, the wet interface of expansion joints or the adhesion of dirt. Therefore, in view of the problems existing in the construction of polyurethane watertight materials, an experimental study was carried out on the adhesive properties of polyurethane watertight materials for channel expansion joints under special construction conditions. The following conclusions are drawn from the experimental study: the bindability of two-component polyurethane watertight materials is greatly affected by mixing time and ambient temperature before construction. The results show that the adhesive property of the two-component polyurethane watertight material increases with the prolongation of stirring time, and the lower the ambient temperature, the greater the mixing difficulty of the two-component polyurethane watertight material, the more difficult the construction is, and the worse the mixing uniformity is. The worse the bond is. When the ambient temperature is 15 鈩，

本文编号：1990337