PB-g-PS胶乳改性水泥砂浆的性能研究

Study on Properties ofPB-g-PS Latex-modified Cement Mortars

PB-g-PS胶乳常用于改性水泥砂浆,聚丁二烯对苯乙烯的重量比的范围从70/30,50/50到30/70.保持水灰比为0.5的常数,在20°、相对湿度为90%的空气中养护24 h,接下来在20°的水中养护27 d.这项研究考察了聚丁二烯与苯乙烯的重量比和聚灰比对PB-g-PS胶乳改性水泥砂浆的流动度,抗压、抗折强度及吸水率的影响.实验结果表明,改性砂浆的流动度随着聚灰比的增加而增加,而随聚丁二烯对苯乙烯重量比的增加而减少,PB-g-PS胶乳能显著地降低毛细孔吸水率.此最小值是1.33 kg/m2.PB-g-PS胶乳能显著地影响改性砂浆的力学性能.改性砂浆的抗压强度、和抗折强度都降低.总之,PB-g-PS胶乳可以加入到水泥砂浆里作为水泥改性剂.

The PB-g-PS latex was used to modify cement mortar,and the weight ratios of polybutadiene to styrene ranged from 70/30,50/50 to 30/70.In the constant water-cement ratio of 0.5,and curing 24h at 20℃,RH90 % air followed by 27d at 20℃water.This study examines the effects of weightratiospolybutadiene to styreneand the polymer-cement ratios on the flow,compressive and flexural strength and water absorption rate of PB-g-PS latex modified cement mortar.The experimental results show that the flow of modified mortar is increased with increasing polymer-cement ratios and decreasing weight ratiosof polybutadiene to styrene,PB-g-PS latex can markedly reduce capillary water absorption rate.The minimum is 1.33 kg/m2.PB-g-PS latex can mark influences much on the mechanical properties of modified mortars.The compressive of the polymer modified mortar decreased,and the flexural strength of polymer modified mortar decreased as well.Overview on,PB-g-PS latex can be incorporated into cement mortars as cement modifier.