聚合物对水泥水化进程和砂浆微观结构的影响

The polymer on cement hydration process and on the microstructure of polymer modified cement modified

通过力学性能的测定和红外光谱分析、热分析、扫描电镜分析等研究了聚乙烯-乙烯乙酸酯乳液(简称EVA乳液)对水泥砂浆力学性能的影响,以及水化特性和砂浆的微观结构。结果表明,随着EVA用量的增加,抗压强度逐渐减小,抗折强度先下降后增加。EVA与水泥中的钙离子发生化学络合作用,并且与水泥中的带电物质发生吸附作用,降低了水化速率。聚合物的掺入有利于优化水泥基材料的微观结构,形成的有机无机互穿网络结构提高了砂浆的密实度,增强了砂浆的抗弯曲能力。红外和热重分析也表明聚合物抑制了水化反应的进程,降低了水化度,加之聚合物的高粘性导致离子的转移速率降低,水化产物的含量都有明显的下降。

Polyethylene vinyl acetate(EVA)emulsion was used to investigate the physical and chemical effect of polymer on cement mortar and its influence on the microstructure of mortar.Through mechanical strength analysis,Fourier transform infrared spectroscopy(FTIR),thermal analysis and microstructure analysis,it is shown that the chemical interaction between the polymer and the calcium ions in the cement forms chemical bond that is relatively stable and adsorbs with the charged substances in the cement-based materials,reducing the water absorption.The incorporation of the polymer is beneficial to optimizing the microstructure of the cement-based materials,and the formed interpenetrating network structure improves the compactness and enhances the bending resistance of the mortar.Infrared and thermogravimetric analysis(TG)also showed that the polymer inhibited the progress of the hydration reaction and reduced the degree of hydration.In addition,the higher viscosity of the polymer led to a significant reduction in the ion transfer rate and in the hydration product content.