›› 2018, Vol. 39 ›› Issue (5): 1543-1552.doi: 10.16285/j.rsm.2016.1308

• 基础理论与实验研究 •    下一篇

活性氧化镁碳化固化粉质黏土微观机制

刘松玉1, 2,曹菁菁1, 2, 3,蔡光华1, 2   

  1. 1. 东南大学 岩土工程研究所,江苏 南京 210096;2. 东南大学 江苏省城市地下工程与环境安全重点实验室,江苏 南京 210096; 3. 南京市测绘勘察研究院股份有限公司,江苏 南京 210019
  • 收稿日期:2016-06-06 出版日期:2018-05-11 发布日期:2018-06-12
  • 作者简介:刘松玉,男,1963年生,博士,教授,博士生导师,主要从事特殊土地基处理及环境岩土等方面的研究工作
  • 基金资助:

    国家自然科学基金(No.41330641, No.451279032);国家重点研发计划项目(No.42016YFC0800201);江苏省交通工程建设局科技项目(No.2018T01);“十二五”国家科技支撑计划项目(No. 2012BAJ01B02-01);江苏省普通高校研究生科研创新计划资助项目(No.KYLX_0147)。

Microstructural mechanism of reactive magnesia carbonated and stabilized silty clays

LIU Song-yu1, 2, CAO Jing-jing1, 2, 3, CAI Guang-hua1, 2   

  1. 1. Institute of Geotechnical Engineering, Southeast University, Nanjing, Jiangsu 210096, China; 2. Jiangsu Key Laboratory of Urban Underground Engineering and Environmental Safety, Southeast University, Nanjing, Jiangsu 210096, China; 3. Nanjing Institute of Surveying, Mapping & Geotechnical Investigation Corporation, Nanjing, Jiangsu 210019, China
  • Received:2016-06-06 Online:2018-05-11 Published:2018-06-12
  • Supported by:

    This work was supported by the National Natural Science Foundation of China(41330641, 51279032); the National Key Research and Development Program of China (2016YFC0800201); the Science and Technology Project of Jiangsu Traffic Engineering Construction Bureau (2018T01); the Key Projects in the National Science & Technology Pillar Program during the Twelfth Five-year Plan Period(2012BAJ01B02-01) and the Fundamental Research Funds for the Jiangsu Provincial Innovation Foundation for Postgraduate of Regular Institutions of Higher Learning(KYLX_0147).

摘要: 以活性氧化镁碳化固化粉质黏土为研究对象,通过无侧限抗压强度试验、酸碱度测试、X射线衍射试验、压汞试验和扫描电镜试验,研究了不同初始含水率和碳化时间影响下活性氧化镁碳化加固粉质黏土的强度、pH值、碳化产物和微观结构等变化。根据碳化固化土强度与碳化产物含量及累积孔隙体积间的内在联系,提出了粉质黏土的碳化反应微观模型。结果表明:随碳化时间增加和初始含水率减小,碳化固化土的碳化产物含量增加、累积孔隙体积减小,同时氧化镁碳化加固土的强度提高;碳化固化土的pH值随碳化时间不断减小,而随初始含水率变化不大;最后提出了粉质黏土的碳化反应微观模型,确定了活性氧化镁固化粉质黏土在碳化约6.0 h时可获得最高强度。

关键词: 活性氧化镁, 粉质黏土, 碳化, 土体固化, 微观机制

Abstract: In this study, reactive magnesia (MgO) is used as a binder to carbonate and stabilise silty clay. The changes of unconfined compressive strength, soil pH, carbonation products, and microstructure of the silty clay carbonated and stabilized by reactive MgO are studied at different carbonation time and initial water contents through the experiments of unconfined compression, pH, X-ray diffraction, mercury intrusion porosimetry and scanning electron microscope, respectively. The micromodel of carbonation reaction of silty clay is proposed according to the intrinsic relationships between the strength of carbonated soil and contents of carbonation products as well as the cumulative pore volume. The results show that with the increase of the carbonation time or the decrease of the initial water content of carbonated samples, the carbonation products increase, and the strength of reactive MgO stabilized soil gradually increases with the decrease of cumulative pore volume. Moreover, the pH values of reactive MgO-stabilized soil decreased with the increase of the carbonation time, whereas the initial water contents show no obvious changes. Finally, the micromodel of carbonation reaction of silty clay is established, and the highest strength of reactive MgO-stabilized silty clay is determined after about 6 hours of carbonation.

Key words: reactive magnesia, silty clay, carbonation, soil stabilisation, microstructural mechanism

中图分类号: 

  • TU 411

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