一种改性聚合硫酸铝型速凝剂的适应性研究

介绍了一种改性聚合硫酸铝型液体速凝剂的性能特点,通过凝结时间和强度测试,重点研究了该速凝剂对不同种类水泥的适应性问题,以及环境温度对速凝剂性能的影响,并通过XRD测试,分析了该速凝剂的促凝机理。结果表明:该速凝剂具有良好的水泥适应性,掺量在4.5%~6.5%时能满足JC477—2005《喷射混凝土用速凝剂》规定的一等品要求,该速凝剂具有良好的温度适应性,当环境温度从20℃降至-10℃时,速凝剂仍可稳定保存,掺量仅需从4.5%增加至5.5%,便能使凝结时间达到一等品要求,能满足低温施工需要。XRD测试结果表明,该速凝剂是通过促进钙矾石生成而达到速凝效果。

Study on Adaptability of Flash Setting Admixture Composed of Modified Polyaluminium Sulfate

A liquid flash setting admixture composed of modified polyaluminium sulfate was introduced.The effects of cement kinds and test temperature on the flash setting admixture were discussed by setting time and compressive strength test.The setting mechanism of this admixture were analysed by XRD test.The results show that the flash setting admixture has cement and temperature adaptability.By using different kind of Portland cement,the performance of this admixture meet the requirements of JC477—2005 Flash setting admixtures for shotcrete when the dosage is between 4.5%~6.5%.This admixture can be stored steadily at-10℃.When the environment temperature decrease from 20℃to-10℃,the dosage of admixture just increase from 4.5%to 5.5%to meet the requirements of the standard.The XRD test results show that the setting mechanism of this admixture is promoting the formation of ettringite.