Volume 24 Issue 3
Jun.  2016
Turn off MathJax
Article Contents
LIU Yi. 2016: INVESTIGATION ON THE SWELLING PROPERTIES AND MICROSTRUC-TURE MECHANISM OF COMPACTED GAOMIAOZI BENTONITE. JOURNAL OF ENGINEERING GEOLOGY, 24(3): 451-458. doi: 10.13544/j.cnki.jeg.2016.03.015
Citation: LIU Yi. 2016: INVESTIGATION ON THE SWELLING PROPERTIES AND MICROSTRUC-TURE MECHANISM OF COMPACTED GAOMIAOZI BENTONITE. JOURNAL OF ENGINEERING GEOLOGY, 24(3): 451-458. doi: 10.13544/j.cnki.jeg.2016.03.015

INVESTIGATION ON THE SWELLING PROPERTIES AND MICROSTRUC-TURE MECHANISM OF COMPACTED GAOMIAOZI BENTONITE

doi: 10.13544/j.cnki.jeg.2016.03.015
  • Received Date: 2015-03-17
  • Rev Recd Date: 2015-04-28
  • Publish Date: 2016-06-25
  • Bentonite has the property of swelling when meeting water. It is a desirable buffer/backfill material in the deep geological disposal for high-level radioactive waste. The expansibility is one of the most important properties for bentonite as the buffer/backfill material, and is influenced by a number of factors. For study the expansibility of bentonite, Gaomiaozi(GMZ)bentonite was taken as the research object. Gaomiaozi(GMZ)bentonite had been proposed as the first choice of buffer/backfill material for the high-level radioactive waste disposal in China. Its expansibility was studied by the constant volume swelling test method which is one of the commonest methods for measuring the swelling pressure of bentonite. In these tests, water content and dry density were chosen as the control variable. Two types of dry density and three types of water content were adopted in the tests. Results of the swelling tests show that the shape of swelling curves and the maximum swelling pressure depend on the water content and dry density of the bentonite samples. There are conspicuous double-peak shapes of the swelling curve for the samples with low dry density. When the dry density is high, the swelling curves have different shapes with different water contents. The curve's shapes change from double-peak to smooth curve with the water content increasing. For analysis of the results of swelling tests, the mercury intrusion porosimetry(MIP)test has been carried out. MIP test results indicate that the pore size distribution curves of samples also depend on the water content and dry density, with the volume of inter-aggregate pores increasing as the water content or dry density decreases. In accordance with the relevant researches, the swelling curve of GMZ bentonite is deeply influenced by the volume of the inter-aggregate pores. When meeting water, the bentonite aggregates absorb water and swell quickly. When the inter-aggregate pores are large enough, there will be sufficient space for swelled aggregates to form a provisional structure. The provisional structure will collapse with the swelling pressure reach the limit load. Then the measured pressure fall and inner structure of bentonite recombination. The hydration is continuous so that the curve will get the second peak. Therefore, a double-peak structure can be observed when the space of inter-aggregate is great. With the volume of inter-aggregate pore decrease, the swell curve of bentonite changes from a double-peak structure to a smooth curve.
  • loading
  • Bird P. 1984. Hydration phase diagrams and friction of montmorillonite under laboratory and geologic conditions, with implications for shale compaction, slope stability, and strength of fault gauge[J]. Tectonophysics,107(3-4):235~260.

    Gray M N,Cheung S C,Dixon D A. 1984. Influence of sand content on swelling pressures and structure developed in statically compacted Na-bentonite[M]. Mississauga:Atomic Energy of Canada Limited.

    Imbert C,Olchitzky E,Lassabatere T,et al. 2005. Evaluation of a thermal criterion for an engineered barrier system[J]. Engineering Geology,81(3):269~283.

    Komine H,Ogata N. 1994. Experimental study on swelling characteristics of compacted bentonite[J]. Canadian Geotechnical Journal,31(4):478~490.

    Komine H,Ogata N. 1996. Prediction for swelling characteristics of compacted bentonite[J]. Canadian Geotechnical Journal,33(1):11~22.

    Li X M,Wang Y H. 2003. Regressive analysis of swelling and shrinkage deformation rule of expansive soils[J]. Journal of Xiangtan Mining Institute,18(2):30~33.

    Liu Q S,Wang Z J. 2002. Influence factors of sand-bentonite mixtures on the swelling pressure[J]. Chinese Journal of Rock Mechanics and Engineering,21(7):1054~1058.

    Liu Y M,Xu G Q,Liu S F,et al. 2001. Study on compatibility and swelling property of buffer/backfill material for HLW repository[J]. Uranium Geology,17(1):44~47.

    Marcial D,Delage P,Rui Z X,et al. 2006. Ageing effects in a compacted bentonite:a microstructure approach[J]. Gétechnique,56(5):291~304.

    Pusch R. 1982. Mineral-water interactions and their influence on the physical behavior of highly compacted Na bentonite[J]. Canadian Geotechnical Journal,19(3):381~387.

    Qian L X. 2007. A fundamental study of GMZ bentonite as buffer material in deep geological disposal for high-level radioactive waste[D]. Shanghai:Tongji University.

    Qin B,Chen Z H,Liu Y M,et al. 2009. Characteristics of 3D swelling pressure of GMZ001 bentonite[J]. Chinese Journal of Geotechnical Engineering,31(5):756~763.

    Shen Z Y. 2001. Latest advances in HLW geological disposal in the world[J]. Chinese Geology,28(12):19~21.

    Sposito G,Prost R. 1982. Structure of water adsorbed on smectites[J]. Chemical Reviews,82(6):553~573.

    Suzuki S,Prayongphan S,Ichikawa Y,et al. 2005. In situ observations of the swelling of bentonite aggregates in NACL solution[J]. Applied Clay Science,29(2):89~98.

    Wang J. 2007. Geological disposal of high level radio active waste:progress and challenges[J]. Engineering Science,10(3):58~64.

    Wang J,Su R,Chen W M,et al. 2006. Deep geological disposal of high-level radioactive wastes in China[J]. Chinese Journal of Rock Mechanics and Engineering,25(4):649~658.

    Xie Y,Chen Z H,Li G,et al. 2006. Test research on three-dimensional swelling pressure of Nanyang expansive soil[J]. Journal of Logistical Engineering University,1:11~14.

    Xie Y,Chen Z H,Sun S G,et al. 2007. Test research on three-dimensional swelling pressure of remolded expansive clay[J]. Rock and Soil Mechanics,28(8):1636~1642.

    Xu G Q. 1996. Selection of buffer/backfill materials and their additives[J]. Uranium Geology,12(4):238~244.

    Xu G Q,Li Y L,Gu Q F,et al. 1996. Selection of bentonite deposits[M]. Beijing:Beijing Research Institute of Uranium Geology, 1996.

    Xu Y F,Xiang G S,Chu F F,et al. 2014. Fractal model for swelling deformation of bentonite[J]. Journal of Engineering Geology,22(5):785~791.

    Yang C Q,Dong D,Tan B,et al. 2014. Laboratory tests on three-directional swelling deformation of remolded expansive soil[J]. Journal of Engineering Geology,22(2):188~195.

    Ye W M,Huang Y,Cui Y J,et al. 2005. Microstructural changing characteristics of densely compacted bentonite with suction under unconfined hydrating conditions[J]. Chinese Journal of Rock Mechanics and Engineering,24(24):4570~4575.

    Ye W M,Qian L X,Chen B,et al. 2009. Characteristics of micro-structure of densely compacted Gaomiaozi bentonite[J]. Journal of Tongji University(Natural Science),37(1):31~35.

    Ye W M,Schanz T,Qian L X,et al. 2007. Characteristics of swelling pressure of densely compacted Gaomiaozi bentonite GMZ01[J]. Chinese Journal of Rock Mechanics and Engineering,26(S2):3861~3865.

    李献民,王永和. 2003. 膨胀黏土胀缩变形规律的回归分析[J]. 湘潭矿业学院学报,18(2):30~33.

    刘泉声,王志俭. 2002. 砂-膨润土混合物膨胀力影响因素的研究[J]. 岩石力学与工程学报,21(7):1054~1058.

    刘月妙,徐国庆,刘淑芬,等. 2001. 我国高放废物处置库缓冲/回填材料压实膨胀特性研究[J]. 铀矿地质,17(1):44~47.

    钱丽鑫. 2007. 高放废物深地质处置库缓冲材料-高庙子膨润土基本特性研究[D]. 上海:同济大学.

    秦冰,陈正汉,刘月妙,等. 2009. 高庙子膨润土GMZ001三向膨胀力特性研究[J]. 岩土工程学报,31(5):756~763.

    沈珍瑶. 2001. 世界各国高放废物地质处置最新进展[J]. 中国地质,28(12):19~21.

    王驹. 2007. 高放废物地质处置:进展与挑战[J]. 中国工程科学,10(3):58~64.

    王驹,苏锐,陈伟明,等. 2006. 中国高放废物深地质处置[J]. 岩石力学与工程学报,25(4):649~658.

    谢云,陈正汉,李刚,等. 2006. 南阳膨胀土三向膨胀力规律研究[J]. 后勤工程学院学报,1:11~14.

    谢云,陈正汉,孙树国,等. 2007. 重塑膨胀土的三向膨胀力试验研究[J]. 岩土力学,28(8):1636~1642.

    徐国庆. 1996. 缓冲/回填材料与添加剂的选择[J]. 铀矿地质,12(4):238~244.

    徐国庆,李永利,顾绮芳,等. 1996. 膨润土矿床筛选[M]. 北京:核工业北京地质研究院.

    徐永福,项国圣,褚飞飞,等. 2014. 膨润土膨胀变形的分形模型[J]. 工程地质学报,22(5):785~791.

    杨长青,董东,谭波,等. 2014. 重塑膨胀土三向膨胀变形试验研究[J]. 工程地质学报,22(2):188~195.

    叶为民,黄雨,崔玉军,等. 2005. 自由膨胀条件下高压密膨胀黏土微观结构随吸力变化特征[J]. 岩石力学与工程学报,24(24):4570~4575.

    叶为民,钱丽鑫,陈宝,等. 2009. 高压实高庙子膨润土的微观结构特征[J]. 同济大学学报(自然科学版),37(1):31~35.

    叶为民,Schanz T,钱丽鑫,等. 2007. 高压实高庙子膨润土GMZ01的膨胀力特征[J]. 岩石力学与工程学报,26(增2):3861~3865.
  • 加载中

Catalog

    通讯作者: 陈斌, bchen63@163.com
    • 1. 

      沈阳化工大学材料科学与工程学院 沈阳 110142

    1. 本站搜索
    2. 百度学术搜索
    3. 万方数据库搜索
    4. CNKI搜索
    Article views (2700) PDF downloads(632) Cited by()
    Proportional views
    Related

    /

    DownLoad:  Full-Size Img  PowerPoint