纤维素醚-水泥水化特征及机理评述

Review on the characteristics and mechanism of cellulose ether-cement hydration

纤维素醚会明显延缓水泥的凝结和硬化,通常降低水泥水化热的释放速度和峰值,延迟水泥水化产物的生成,影响水化产物的形貌和水泥浆的孔结构。纤维素醚影响水泥水化的主要机理包括吸附、阻碍水泥颗粒的溶解以及延缓水化产物的成核和生长。纤维素醚对水泥水化的延迟与水泥的化学组成和纤维素醚的化学结构密切相关,高黏的纤维素醚溶液阻碍离子扩散也是水泥水化延迟的原因。纤维素醚具有碱稳定性。

Cellulose Ethers（CEs） will significantly retard the setting and hardening of cement paste,commonly decreasing the release rate and peak of hydration heat,slowing down the formation of hydration product,transforming the morphology of hydration product and pore structure of cement paste.The mainly mechanism of CE influencing cement hydration includes：Absorption,slowing down the dissolution of cement particle,as well as retarding nucleation and growth of some hydration products.CE-cement hydration is closely relevant to cement compositions and the chemical structure of CE.Ions diffusion barrier,induced by the high viscous solution of cellulose ethers,is also the cause of retarding cement hydration.CEs are stable in alkaline media.