低分子量混凝土抑泥剂的制备及性能研究

Preparation and Performance of Low Molecular Weight Clay-retraining Reagent for Concrete

摘要:

针对混凝土原材料中黏土对混凝土带来不利影响，本文通过自由基共聚反应机理，以丙烯酸（AA）、丙烯酰胺（AM）为单体，过硫酸铵为引发剂，异丙醇为链转移剂，制备了2种低分子量水溶性聚合物混凝土抑泥剂PAAS和AA-AM。通过傅里叶变换红外光谱（FTIR）、热重（TGA）以及凝胶渗透色谱（GPC）对聚合物进行了表征，并通过水泥净浆流动度、混凝土坍落度和扩展度对其应用性能进行了检测。结果表明，2种聚合物抑泥剂均具有一定的抑泥性能，在高含泥量混凝土的应用中，能够显著降低水泥净将流动度、混凝土坍落度和扩展度的损失，掺入聚合物AA-AM后，混凝土1h后的坍落度从180mm提高到210mm，扩展度从310mm提高到430mm。

Abstract:

In view of the negative effect of the clay in the concrete, two kinds of low molecular weight clay-retraining reagents, PAAS and AA-AM, were synthesized through the mechanism of free radical copolymerization, ammonium persulfate as initiator, isopropyl alcohol as chain transfer. The polymers were analyzed by fourier infrared spectroscopy (FTIR), thermogravimetric (TGA) and gel permeation chromatography (GPC). Meanwhile the polymers were characterized by the cement paste fluidity, concrete slump and expansion. The results showed that the two kinds of polymers had a certain performance on inhibiting clay which could reduce the cement paste fluidity, concrete slump and expansion losing. The concrete slump increased from 180mm to 210mm and the concrete expansion advanced from 310mm to 430mm while adding the polymer AA-AM.