改性淀粉醚对新拌砂浆相关性能的影响

Effect of modified starch ether on the properties of fresh mortar

就改性淀粉醚以不同比例取代纤维素醚后对掺纤维素醚砂浆新拌阶段相关性能的影响进行了试验研究。结果表明:尽管淀粉醚的水溶液黏度较低,但淀粉醚却能增大水泥浆体的黏度;掺淀粉醚可改善砂浆的流动性、提高砂浆的湿表观密度;淀粉醚对砂浆保水性的改善效果较差,但可显著提高砂浆的屈服值,从而赋予砂浆较好的抗流挂性;淀粉醚在低掺量情况下对砂浆凝结时间无明显影响,但当其对纤维素醚的取代率超过30%时,砂浆的凝结时间会缩短。

This paper studies the effect of replacement ratio of modified starch ether （SE） on the property of fresh mortar,the result shows that SE can increase the viscosity of cement paste under certain dosage although its lower viscosity. Meanwhile mortar flow and its wet apparent density will be modified by utilizing SE,water retention will be sharply decreased at the same time. Rheology test indicates that SE would raise mortar yield stress value which helps to improve sag resistance. SE has no significant effect on the setting time,but if replacement ratio is above 30%,the setting time will be reduced slightly.