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聚羧酸系减水剂作为第三代减水剂,具有掺量少、减水率高、保坍性能好、与水泥适应性强、混凝土收缩小等特点。正是由于这些优点,加之其本身与环境友好的特点,在国内外已得到普遍的认可。目前,国内重点市政、铁路、桥梁等工程几乎全部使用了聚羧酸系减水剂,一些地区的商品混凝土搅拌站也使用了聚羧酸减水剂,很多工程取得了较满意的效果,与此同时,在应用中也发现了一些问题。最近有许多技术人员反映使用聚羧酸减水剂后坍落度损失很快,即出机坍落度很好,但短时间内就会变得几乎无流动性。有些技术人员对聚羧酸减水剂的收样检测办法比较迷惑,很多产品净浆流动度很大,而混凝土扩展度却很小。本期特别策划邀请相关专家就该问题如何应对及采取的措施予以解答。
As the third generation superplasticizer, polycarboxylate superplasticizer has the characteristics of low dosage, high water reducibility, good slump performance, strong adaptability with cement and small shrinkage of concrete. It is because of these advantages, together with their own characteristics of being environmentally friendly, have gained universal acceptance both at home and abroad. At present, most of the domestic municipal, railway, bridge and other projects almost all use of polycarboxylate superplasticizer, some areas of commercial concrete mixing station also used polycarboxylate superplasticizer, many projects have achieved more satisfactory results, and At the same time, some problems have also been found in the application. Recently, many technicians have reported that the loss of slump after using the polycarboxylate water reducer is very rapid, that is, the slump of the extruder is very good, but almost no fluidity will be obtained in a short time. Some technicians on the polycarboxylate superplasticizer sampling approach more confused, many products have a great flow of paste, and concrete expansion is very small. This issue special planning to invite relevant experts on how to deal with the problem and measures to be answered.