为研究降温过程中硫酸盐渍土盐胀与冻胀的内在联系,以冻结温度作为土体盐胀与冻胀的分界点,通过改变降温过程中盐渍土的水盐含量,控制盐胀与冻胀变形相对大小,开展了一系列盐渍土冻结变形试验,分析了水盐变化过程中,土体盐胀与冻胀的变化规律。结果表明降温过程中的盐胀与冻胀存在叠加效应,即总变形与总结晶体积之间不满足正相关关系,总变形受盐胀与冻胀强弱关系的影响,满足盐胀与冻胀的均势规律,即在盐胀变形与冻胀变形相等时,盐、冻胀总变形最小,总变形与盐胀比之间满足“M”形变化规律。研究结果对深入理解盐、冻胀变形的机理,建立盐、冻胀变形计算模型,以及开展盐、冻胀变形病害防治具有积极意义。
Abstract
The aim of this study is to explore the connection between salt expansion and frost heave in cooling sulfate saline soil. Freezing deformation tests are conducted on sulfate saline soil samples to examine the variations of salt expansion and frost heave of soil under varying water and salt content. The salt expansion and frost heave are controlled by changing the water content and salt content in the freezing process. Freezing temperature is set as the demarcation point identifying between salt expansion and frost heave. Results reveal a duplicate effect between salt expansion and frost heave in the freezing process, i.e. there is no positive correlation between total deformation of samples and crystalline volume. Total deformation obeys the law of the balance of power between salt expansion and frost heave, which means that total deformation reaches the minimum when salt expansion deformation equals frost heave deformation. The curve between total deformation and ratio of salt expansion displays an M-shape. The research findings are of active significance for further understanding the mechanism, building models, and hazard prevention of salt expansion and frost heave.
关键词
硫酸盐渍土 /
盐胀 /
冻胀 /
冻结温度 /
冻结变形试验 /
叠加效应 /
均势规律
Key words
sulfate saline soil /
salt expansion /
frost heave /
freezing temperature /
freezing deformation test /
duplicate effect /
law of the balance of power
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参考文献
[1] 牛玺荣,高江平.综合考虑盐胀和冻胀时硫酸盐渍土体积变化关系式的建立[J].岩土工程学报,2015,37(4):755-760.
[2] 肖泽岸,赖远明,尤哲敏.冻融循环作用下含盐量对Na2SO4土体变形特性影响的试验研究[J].岩土工程学报,2017,39(5):953-960.
[3] KONIORCZYK M, GAWIN D. Modelling of Salt Crystallization in Building Materials with Microstructure: Poromechanical Approach[J]. Construction & Building Materials, 2012, 36:860-873.
[4] ESPINOSA R M, FRANKE L, DECKELMANN G. Model for the Mechanical Stress Due to the Salt Crystallization in Porous Materials[J]. Construction and Building Materials, 2008, 22(7):1350-1367.
[5] ESPINOSA R M, FRANKE L, DECKELMANN G. Phase Changes of Salts in Porous Materials: Crystallization, Hydration and Deliquescence[J]. Construction & Building Materials, 2008, 22(8): 1758-1773.
[6] SCHERER G W. Crystallization in Pores[J]. Cement & Concrete Research, 1999, 29(8): 1347-1358.
[7] SCHERER G W. Stress from Crystallization of Salt[J]. Cement & Concrete Research, 2004, 34(9): 1613-1624.
[8] LAI Y, WU D, ZHANG M. Crystallization Deformation of a Saline Soil During Freezing and Thawing Processes[J]. Applied Thermal Engineering, 2017, 120: 463-473.
[9] WU D, LAI Y, ZHANG M. Heat and Mass Transfer Effects of Ice Growth Mechanisms in a Fully Saturated Soil[J]. International Journal of Heat & Mass Transfer, 2015, 86: 699-709.
[10] WAN X, HU Q, LIAO M. Salt Crystallization in Cold Sulfate Saline Soil[J]. Cold Regions Science and Technology, 2017, 137: 36-47.
[11] LITVAN G G.Phase Transitions of Adsorbates: Ⅳ,Mechanism of Frost Action in Hardened Cement Paste[J]. Journal of the American Ceramic Society,2010,55(1):38-42.
[12] 徐学祖,王家澄,张立新.冻土物理学[M].北京:科学出版社,2001.
[13] 邴 慧,何 平,杨成松,等.开放系统下硫酸钠盐对土体冻胀的影响[J]. 冰川冻土,2006(1):126-130.
[14] 李青海,顾同欣,于升松,等.南翼山油田卤水低温结晶过程研究[J]. 物理化学学报,2011, 27(8):1803-1808.
[15] 万旭升,赖远明.硫酸钠溶液和硫酸钠盐渍土的冻结温度及盐晶析出试验研究[J].岩土工程学报,2013,35(11): 2090-2096.
[16] VERBECK G J, KLIEGER P. Studies of Salt Scaling of Concrete[J]. Highway Research Board Bulletin, 1957, 150: 1-17.
[17] CHANDRA S, XU A. Influence of Presaturation and Freeze-Thaw Test Conditions on Length Changes of Portland Cement Mortar[J]. Cement & Concrete Research, 1992, 22(4): 515-524.
[18] SELLEVOLD E J, FARSTAD T. Frost/Salt-Testing of Concrete: Effect of Test Parameters and Concrete Moisture History[J]. Nordic Concrete Research, 1991, 10: 83-100.
[19] LITVAN G G. Frost Action in Cement Paste[J]. Matériaux et Construction, 1973, 6(4): 293-298.
[20] 邓友生, 周成林. 硫酸钠溶液的盐胀与冻胀[J]. 冰川冻土, 2009, 31(5): 920-924.
[21] 李星星,王思敬,肖锐铧,等.硫酸钠溶液在降温结晶过程中的盐胀与冻胀[J].岩土工程学报,2016,38(11):2069-2077.
基金
国家自然科学基金项目(11962016);教育部春晖计划项目(Z2016178);长江师范学院校级科研项目(2017XJQN16)
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