丙烯酸改性聚醋酸乙烯酯乳液对砂浆性能的影响

Effect of Acrylic Acid Modified Polyvinyl Acetate Emulsion on Property of Mortar

固定砂浆的流动度为150±10 mm,研究了丙烯酸改性聚醋酸乙烯酯乳液(聚合物乳液)掺量对砂浆保水性、吸水率、粘结强度和压折比的影响。实验结果表明:聚合物乳液改性新拌砂浆的保水性能随乳液掺量的增加而增大,硬化水泥砂浆的失水率和28 d硬化水泥砂浆的吸水率随聚合物乳液掺量的增大而减小,新拌砂浆与水泥基材料的粘结强度随着聚合物乳液掺量的增加不断增强;随着聚合物乳液掺量的增加,28 d硬化水泥砂浆的抗压强度减小而抗折强度增大,压折比不断减小,在掺量在10%时,压折比降低至3左右,说明砂浆的韧性得到不断提高。因此,在砂浆中加入适量的聚合物乳液,可以明显改善砂浆性能。

Effects of content of acrylic acid modified polyvinyl acetate emulsion（polymer emulsion） on water retention,absorption ratio, bond strength and ratio of compressive strength to flexurai strength of mortar at fixed mortar fluidity of 150 ＋ 10 mm were investigated. Results：the water retention of mortar increased with polymer emulsion content.The water loss rate and absorption ratio of hardened cement mortar decreased with polymer emulsion content.The bond strength of cement mortar with cement base material increased with polymer emulsion content.The compressive strength of mortar at 28d decreased with polymer emulsion content.But the flexurai strength increased and the ratio of compressive strength to flexurai strength decreased.When the polymer emulsion content was 10%, the ratio of compressive strength to flexurai strength compressive strength decreased to 3.The performance of the mortar can be improved when the appropriate content of polymer emulsion is added.