| 摘要: |
| 为了提高硫氧镁（MOS）水泥早期抗压强度，向MOS体系中掺入热处理后的5Mg（OH）2·MgSO4·7H2O（517）晶须，分析了热处理前后的517晶须对MOS水泥凝结时间、抗压强度、物相组成、微观形貌和孔结构的影响. 结果表明：5Mg（OH）2·MgSO4·4H2O和5Mg（OH）2·MgSO4在MOS浆体中均可吸附水分子形成517晶须，并在体系中发挥胶结-晶种协同作用，促进517晶须生长，这缩短了MOS水泥初、终凝时间，优化了MOS水泥孔结构，提高了MOS水泥早期和后期抗压强度； MOS体系中517晶须的掺量不宜超过4%，且经100、150 ℃热处理的517晶须较未经热处理的517晶须对MOS水泥性能优化效果更强. |
| 关键词: 硫氧镁水泥 晶种 协同作用 抗压强度 水化产物 微观结构 |
| DOI：10.3969/j.issn.1007-9629.2023.08.003 |
| 分类号:TQ172.1 |
| 基金项目:国家自然科学基金面上项目（51778101）；国家重点研发计划（2020YFC1909304）；国家自然基金联合基金项目（U1908227）；辽宁省镁质材料与镁资源工程研究中心开放课题基金资助项目 |
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| Effect of 5Mg（OH）2·MgSO4·7H2O Whiskers after Heat Treatment on Compressive Strength of Magnesium Oxysulfate Cement |
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WANG Dongsheng1, HU Zhiqi2, CHEN Xiaoyang3, CHEN Bing4, GUAN Yan5,6
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1.School of Civil Engineering， University of Science and Technology Liaoning， Anshan 114051， China;2.Faculty of Infrastructure Engineering， Dalian University of Technology， Dalian 116024， China;3.School of Chemical Engineering， University of Science and Technology Liaoning， Anshan 114051， China;4.School of Naval Architecture， Ocean & Civil Engineering， Shanghai Jiao Tong University， Shanghai 200240， China;5.School of Materials and Metallurgy， University of Science and Technology Liaoning， Anshan 114051， China;6.Liaoning Provincial Magnesium Materials and Magnesium Resources Engineering Research Center， University of Science and Technology Liaoning， Anshan 114051， China
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| Abstract: |
| To enhance the early compressive strength of magnesium oxysulfate（MOS） cement， 5Mg（OH）2·MgSO4·7H2O （517） whiskers after heat treatment were added to the MOS system. The effect of the 517 whiskers with and without heat treatment on the setting time， compressive strength， phase composition， microstructure and pore structure of MOS cement was investigated. The results show that both 5Mg（OH）2·MgSO4·4H2O and 5Mg（OH）2·MgSO4 can adsorb water molecules from the MOS slurry to convert into 517 whiskers. This can further promote the formation of 517 whiskers in MOS system due to the adhesive-crystal seed synergistic effect of these two dehydrated phases， resulting in a shortening in the initial and final setting time， an optimization in the pore structure， and an improvement in the early and late compressive strength of MOS cement. In addition， the content of 517 whiskers used to prepare MOS cement should not exceed 4%. Compared with 517 whiskers without any heat treatment， the 517 whiskers treated at 100 ℃ and 150 ℃ have a stronger positive effect on the performance of MOS cement. |
| Key words: magnesium oxysulfate cement crystal seed synergistic effect compressive strength hydration product microstructure |
