基于砂浆流动性的改性胶粉微观界面机理的研究

Modified Powder Micro Interface Mechanism Based on Mortar Fluidity

以NaOH溶液和表面活性剂分别对胶粉进行改性,利用扫描电子显微镜(SEM)、傅立叶红外光谱仪(FTIR)与液-固界面视频接触角分析仪对改性胶粉表面进行表征分析,在二次改性体系下研究两种胶粉改性途径对水泥胶砂工作性能的影响。研究表明:表面改性可以不同程度减小胶粉与水的接触角,增强胶粉的亲水性,提高水泥基胶凝材料的流动性能,有利于其工作性能的改善;同时,NaOH溶液可以祛除胶粉表面的杂质使其更加圆滑,但过多的NaOH不利于其亲水性能的改善,表面活性剂可使胶粉表面引入含氧官能团,提升亲水性,但二次改性效果并不能加成;两种改性途径中,减少胶粉表面杂质对亲水性能的提升大于表面改性剂含氧官能团的引入作用。实验研究为胶粉改性方法的探索提供了理论基础,对胶粉改性混凝土的工业化生产提供了依据。

Using NaOH solution and surfactant modify the powder. Use SEM, FI＇IR and liquid - solid interface contact angle analyzer characterize the surface of modified powder. Analyze two kinds of rubber modifingapproachs on the performance of cement mortar in twice modified system. Research shows that surface modification can reduce the degree of powder contact angle with water in different degree, enhance the hydrophily of powder, improve the flowing properties of cementitious materials, thus is conducive to the performance improvement. NaOH solution can remove impurities on rubber surface to make it more smooth, but too much is not conducive to the hydrophilic property. Surfactant can add oxygen-containing functional groups to the surface and enhance the hydrophilieity. But two modification effects do not superpose. Enhancement of the surface hydrophilicity of the rubber powder by removing impurities on rubber surface is greater than using surfaetant to add oxygen containing functional groups. The research provides a theoretical basis of modification methods for rubber powder and the basis of industrial production of rubber modified concrete.