| 摘要: |
| 以轻烧MgO和MgCl2·6H2O为主要原料，同时掺加少量柠檬酸或柠檬酸铵，制备了氯氧镁水泥（MOC），研究了柠檬酸和柠檬酸铵对MOC水稳定性的改善作用及其作用机理.结果表明：柠檬酸根离子与MgOH+结合形成了有机镁络合层，在阻碍Mg（OH）2产生的同时，促进了5Mg（OH）2·MgCl2·8H2O（5-1-8相）的生成，提高了MOC试件各龄期的抗压强度和体积稳定性；引入柠檬酸和柠檬酸铵没有生成新相，但柠檬酸根离子吸附在5-1-8相表面，显著提高了MOC的水稳定性，并且柠檬酸对MOC水稳定性的改善效果要优于柠檬酸铵. |
| 关键词: 氯氧镁水泥 柠檬酸 柠檬酸铵 水稳定性 |
| DOI：10.3969/j.issn.1007-9629.2022.05.001 |
| 分类号:TU528.01 |
| 基金项目:上海市2020年度“科技创新行动计划”“一带一路”国际合作项目（20520741200） |
|
| Mechanism of Citric Acid and Ammonium Citrate Tribasic on Improving Water Stability of Magnesium Oxychloride Cement |
|
GU Kang, CHEN Bing
|
|
Shanghai Key Laboratory for Digital Maintenance of Buildings and Infrastructure， Shanghai Jiao Tong University， Shanghai 200240， China
|
| Abstract: |
| Magnesium oxychloride cement was prepared by the reaction between light-burned MgO and MgCl2·6H2O in presence of citric acid and ammonium citrate tribasic. Effects of citric acid and ammonium citrate tribasic on improving the water stability of magnesium oxychloride cement and its mechanism were studied. The results show that the citrate combines with MgOH+ to form a stable complex， hindering the precipitation of Mg（OH）2 and promoting the generation of 5Mg（OH）2·MgCl2·8H2O （5-1-8 phase）， which improves the compressive strength and volume stability of magnesium oxychloride cement at all ages. The addition of citric acid and ammonium citrate tribasic induces none of new phase， but significantly enhances the water stability of magnesium oxychloride cement due to the adsorption of citrate onto the surface of 5-1-8 phase. The improvement of water stability by citric acid is better than that by ammonium citrate tribasic. |
| Key words: magnesium oxychloride cement（MOC） citric acid ammonium citrate tribasic water stability |
