六偏磷酸钠分散剂和聚羧酸减水剂对硅镁胶凝材

2.广东省水利水电科学研究院，广东省水利新材料与结构工程技术研究中心，广东 广州  510635）

    摘要：利用XRD、DTA/TG、SEM、AAS以及水化热等方法研究了聚羧酸减水剂和六偏磷酸钠分散剂对硅镁胶凝材料水化物相组成、产物形态、微观结构以及孔溶液离子浓度的影响。结果表明：硅镁胶凝材料水化产物主要为水化硅酸镁、氢氧化镁以及残留的MgO，水化硅酸镁之间以及与其它相之间搭接从而产生胶凝性。聚羧酸减水剂对水化进程几乎无影响；六偏磷酸钠分散剂减缓了试样水化放热速率，提高了反应溶液中的Mg2+浓度和pH值，抑制了Mg（OH）2的生成。

    关键词：氧化镁；水化硅酸镁；六偏磷酸钠；聚羧酸减水剂

    中图分类号：TU528.042        文献标识码：A       文章编号：1001-702X（2018）07-0126-05

 

Effects of sodium hexametaphosphate dispersant and polycarboxylate superplasticizer on

the hydration process of silicon-magnesium cementitiou materials

LI Zhaoheng1，2，LI Wei2，WEI Jiangxiong1，YU Qijun1

（1.School of Materials Science and Engineering，South China University of Technology，Guangzhou 510640，China；

2.Guangdong Research Institute of Water Resources and Hydropower，Guangdong Provincial Engineering Research Center for

 Water Conservancy Advanced Material and Structure，Guangzhou 510635，China）

  Abstract：The effects of polycarboxylate superplasticizer and sodium hexametaphosphate dispersant on the composition and form of hydrates，microscopic structure and the pore solution ion concentration of silicon-magnesium cementitious material were carried out by XRD、DTA/TG、SEM、AAS、hydration heat etc. The results showed that the hydration products of silicon-magnesium cementitious material were magnesium silicate hydrate，magnesium hydroxide and residual MgO，the lapscarf between magnesium silicate hydrate and other phase providing cementitious property. Polycarboxylate superplasticizer has little influence on hydration process，Sodium hexametaphosphate dispersant slowed down the hydration heat release rate，improved the Mg2+ concentration and the pH value of reaction solution，restrains the generation of Mg（OH）2.

    Key words：magnesium oxide，magnesium silicate hydrated，sodium hexametaphosphate，polycarboxylate superplasticizer