速凝剂与水泥的适应性及速凝剂的作用机理研究

Research on the adaptability of accelerators & cement and active mechanism of accelerators

利用XRD及SEM微观测试结果分析了速凝剂和水泥适应性问题的原因及速凝剂促凝机理.研究结果表明:(1)水泥中石膏形态和速凝剂中的NaAlO2含量对速凝剂的促凝效果具有决定性作用;(2)对于以铝氧熟料为主的高碱速凝剂而言,大量AFt的生成是促凝的主要原因.同时,NaOH的激发作用及Ca(OH)2晶体作为中间产物提高浆体早期的固相比例,使浆体失去可塑性,也有助于水泥浆体速凝.

The various cements and accelerators from the factual project were selected and their adaptability was confirmed by experiment.The active mechanism of accelerators was explored by XRD and SEM technology.The results show that：the type of gypsum in the cement and the content of NaAlO2 in the quick-setting agent dominate the promoting efficiency of accelerating agents;and for the high-alkali accelerating agents based on aluminum oxide-based clinker,the large number of AFt formation is the main reason of condensation.At the same time,NaOH excitation function and Ca（OH）2 crystal as the intermediate product to increase the proportion of solid-phase also would cost plasticity of paste and make the paste quick-setting.