聚合物抹灰砂浆试验

Experiment of polymer plastering mortar

针对墙体抹灰层开裂、空鼓、脱落等问题,基于课题组前期成果,制备了7组不同配合比的聚合物抹灰砂浆和1组普通水泥抹灰砂浆,分别测试了各组抹灰砂浆的稠度、分层度、凝结时间、拉伸黏结强度、抗压强度和抗折强度.试验结果表明:聚丙烯纤维、乳胶粉、纤维素醚、木质纤维、膨胀剂等5种添加剂的添加,有效地改善了砂浆的流动性和保水性,提高了砂浆的工作性能和抗裂性能,降低了砂浆的压折比,增强了墙体与砂浆之间的黏结强度,延长了新拌砂浆的凝结时间.分析了上述5种添加剂改善砂浆性能的机理,优选出3组聚合物抹灰砂浆供工程应用参考.

To solve the crack,empty,tympanic and desquamate quality problems in wall plaster layer,seven groups of polymer mortar with different mixture ratios and one group of normal cement mortar were prepared based on previous achievements of the authors＇ research group. The mortar properties of consistency,layered degree,setting time,bonding strength,compressive strength and flexural strength were determined. The experiment results show that the adding of polypropylene fiber,emulsion powder,cellulose ether,wood fiber and expansive agent can improve mixability and water-retaining property of mortar with enhanced working performance and anti-cracking ability of mortar,and can reduce the ratio of compressive strength to flexural strength of mortar with strengthened bond strength between walls and plaster mortar layer and with prolonged setting time of fresh mortar. The improving mechanism of the above five additives to mortar performance is analyzed,and three groups of optional selection polymer mortar are obtained as references for engineering application.