新疆盐渍土地区水泥稳定基层盐胀变形规律及机理
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摘要
为进一步明确硫酸盐对水泥稳定基层膨胀变形的影响规律,基于硫酸盐结晶膨胀理论,设计了水泥稳定砂砾混合料盐胀试验,系统研究了不同硫酸盐含量和环境湿度条件下水泥稳定基层材料的盐胀规律,揭示了水泥稳定基层材料的盐膨胀机理,提出了水泥稳定基层混合料中硫酸盐含量的合理控制范围。结果表明:随混合料含盐量的增加,水泥稳定基层材料变形量从不含盐时的负值变为正值;当含盐量小于1.0%时,混合料每增加0.25%的含盐量,其盐胀率将增大0.012 1%左右;在5～20℃温度范围内,水泥稳定基层材料的盐胀变形随温度的不断降低而快速增长,且在10℃左右,其盐胀变形量达到最大;随环境湿度的增加,水泥稳定基层材料盐膨胀变形量的增大幅度主要由混合料含盐量决定。当含盐量为1.0%时,膨胀变形量受湿度的影响较为显著;含硫酸钠水泥稳定基层材料发生了盐分聚集和结晶作用,结晶后晶体形态变化较大,多数悬浮于固体颗粒之间,且体积显著膨胀,当膨胀力大于微观固体颗粒间的联结力时,便会造成颗粒距离增大,从而在宏观上表现出膨胀变形;水泥稳定基层材料含盐量与其膨胀量存在良好的指数关系,相关系数0.97以上;水泥稳定砂砾混合料中硫酸含盐量宜控制在0.136%以内。
In order to further clarify the influence rule of sulfate on expansion deformation of cement stabilized base, based on the theory of sulfate crystallization expansion, the salt heaving test of cement stabilized gravel mixture is designed. The salt heaving rules of cement stabilized base material under different sulfate content and environmental humidity conditions are studied systematically. The salt heaving mechanism of cement stabilized base material is revealed. The reasonable control range of sulfate content in cement stabilized base mixture is put forward. The result shows that(1) with the increase of sulfate content in the mixture, the deformation of cement stabilized base material changed from negative value without sulfate to positive value.(2) When the sulfate content is less than 1.0%, the salt heaving ratio of the mixture increased by 0.012 1% with the increase of 0.25% sulfate content.(3) In the temperature range of 5～20 ℃, the salt heaving deformation of cement stabilized base material increased rapidly with the decreasing of temperature, and the salt heaving deformation reached the maximum at about 10 ℃.(4) With the increase of environmental humidity, the increase of salt heaving deformation of cement stabilized base material is mainly determined by the sulfate content of the mixture, the expansion deformation is significantly affected by humidity when the sulfate content is 1.0%.(5) Sulfate aggregation and crystallization occurred in the cement stabilized base material with sodium sulfate. After crystallization, the crystal morphology changed greatly, most of them suspended between solid particles, and the volume expanded remarkably. When the expansion force is greater than the bonding force between micro-solid particles, the distance between particles will increase, thus showing the macro-expansion deformation.(6) There is a good exponential relationship between sulfate content and expansion of cement stabilized base material, and the correlation coefficient is above 0.97.(7) Sulfate content in cement stabilized base should be controlled less than 0.136%.
In order to further clarify the influence rule of sulfate on expansion deformation of cement stabilized base, based on the theory of sulfate crystallization expansion, the salt heaving test of cement stabilized gravel mixture is designed. The salt heaving rules of cement stabilized base material under different sulfate content and environmental humidity conditions are studied systematically. The salt heaving mechanism of cement stabilized base material is revealed. The reasonable control range of sulfate content in cement stabilized base mixture is put forward. The result shows that(1) with the increase of sulfate content in the mixture, the deformation of cement stabilized base material changed from negative value without sulfate to positive value.(2) When the sulfate content is less than 1.0%, the salt heaving ratio of the mixture increased by 0.012 1% with the increase of 0.25% sulfate content.(3) In the temperature range of 5～20 ℃, the salt heaving deformation of cement stabilized base material increased rapidly with the decreasing of temperature, and the salt heaving deformation reached the maximum at about 10 ℃.(4) With the increase of environmental humidity, the increase of salt heaving deformation of cement stabilized base material is mainly determined by the sulfate content of the mixture, the expansion deformation is significantly affected by humidity when the sulfate content is 1.0%.(5) Sulfate aggregation and crystallization occurred in the cement stabilized base material with sodium sulfate. After crystallization, the crystal morphology changed greatly, most of them suspended between solid particles, and the volume expanded remarkably. When the expansion force is greater than the bonding force between micro-solid particles, the distance between particles will increase, thus showing the macro-expansion deformation.(6) There is a good exponential relationship between sulfate content and expansion of cement stabilized base material, and the correlation coefficient is above 0.97.(7) Sulfate content in cement stabilized base should be controlled less than 0.136%.
引文
[1]WU Q,ZHU Y.Experimental Studies on Salt Expansion Deformation for Coarse Grain Soil Under Constant Temperature[J].Cold Regions Science&Technology,2002,34(2):59-65.
[2]FUJIMAKI H,SHIMANO T,INOUE M,et al.Effect of A Sulfate Crust on Evaporation from a Bare Saline Soil[J].Vadose Zone Journal,2006,5(4):1246-1256.
[3]马晓宁,王选仓,孙进玲,等.陇南地区膨胀土微观结构与膨胀性[J].南水北调与水利科技,2016,14(3):111-114,149.MA Xiao-ning,WANG Xuan-cang,SUN Jin-ling,et al.Microstructure and Expansion Properties of Expansive Soil in Longnan District[J].South-to-North Water Transfers and Water Science&Technology,2016,14(3):111-114,149.
[4]LAI Y,LIAO M,HU K.A Constitutive Model of Frozen Saline Sandy Soil Based on Energy Dissipation Theory[J].International Journal of Plasticity,2016,78:84-113.
[5]MA Q,LAI Y,ZHANG M,et al.Model Test Study on The Anti-saline Effect of the Crushed-rock Embankment with Impermeable Geotextile in Frozen Saline Soil Regions[J].Cold Regions Science&Technology,2017,141:86-96.
[6]ZHANG Y,YANG Z,LIU J,et al.Impact of Cooling on Shear Strength of High Salinity Soils[J].Cold Regions Science&Technology,2017,141:122-130.
[7]张莎莎,杨晓华,戴志仁.基于均匀设计的砾类硫酸盐渍土盐胀特性试验研究[J].公路交通科技,2009,26(5):29-34.ZHANG Sha-sha,YANG Xiao-hua,DAI Zhi-ren.Experimental Study on Salt Expansion of Gravel Sulfate Salty Soil Based on Uniform Design[J].Journal of Highway and Transportation Research and Development,2009,26(5):29-34.
[8]温小平,翁兴中,张俊,等.道面基层抗硫酸盐侵蚀性能及防范措施[J].公路交通科技,2015,32(9):36-40.WEN Xiao-ping,WENG Xing-zhong,ZHANG Jun,et al.Characteristics of Sulfate Corrosion Resistance of Pavement Base and Precaution Measures[J].Journal of Highway and Transportation Research and Development,2015,32(9):36-40.
[9]王智远,张宏,张海龙.硫酸盐盐渍化道路横向隆起的力学响应分析[J].公路交通科技,2018,35(8):1-6,54.WANG Zhi-yuan,ZHANG Hong,ZHANG Hai-long.Analysis on Mechanical Response of Transverse Uplift of Sulphate Salinized Pavement[J].Journal of Highway and Transportation Research and Development,2018,35(8):1-6,54.
[10]谢宇晨,翁兴中,张俊,等.盐渍土地区道面混凝土盐冻侵蚀研究[J].公路交通科技,2017,34(4):25-31.XIE Yu-chen,WENG Xing-zhong,ZHANG Jun,et al.Study on Salt-frost Erosion of Pavement Concrete in Salty Soil Area[J].Journal of Highway and Transportation Research and Development,2017,34(4):25-31.
[11]温小平,翁兴中,张俊,等.新疆地区粗颗粒盐渍土毛细水上升和隔断层隔断效果研究[J].公路交通科技,2015,32(5):56-60,67.WEN Xiao-ping,WENG Xing-zhong,ZHANG Jun,et al.Research on Effect of Capillary Water Rise and Layer Separation of Coarse Grained Salty Soil in Xinjiang Region[J].Journal of Highway and Transportation Research and Development,2015,32(5):56-60,67.
[12]陈渊召,李振霞.盐渍土工程性质试验[J].公路交通科技,2012,29(12):1-6,13.CHEN Yuan-zhao,LI Zhen-xia.Experiment of Engineering Property of Saline Soil[J].Journal of Highway and Transportation Research and Development,2012,29(12):1-6,13.
[13]牛玺荣,李志农,高江平.盐渍土盐胀特性与机理研究进展[J].土壤通报,2008,39(1):163-168.NIU Xi-rong,LI Zhi-nong,GAO Jiang-ping.Study Progress in Salt Expansion Characteristic and Mechanism of Saline Soil[J].Chinese Journal of Soil Science,2008,39(1):163-168.
[14]包卫星,李志农,罗炳芳.公路工程粗粒盐渍土易溶盐试验方法研究[J].岩土工程学报,2010,32(5):792-797.BAO Wei-xing,LI Zhi-nong,LUO Bing-fang.Test Method for Soluble Salt in Saline Soil in Highway Engineering[J].Chinese Journal of Geotechnical Engineering,2010,32(5):792-797.
[15]包卫星,张莎莎.路用砂类盐渍土盐胀及融陷特性试验研究[J].岩土工程学报,2016,38(4):734-739.BAO Wei-xing,ZHANG Sha-sha.Experimental Study on Salt Expansion and Thawing Subsidence Properties of Sandy Saline Soil[J].Chinese Journal of Geotechnical Engineering,2016,38(4):734-739.
[16]张莎莎,谢永利,杨晓华,等.典型天然粗粒盐渍土盐胀微观机制分析[J].岩土力学,2010,31(1):123-127.ZHANG Sha-sha,XIE Yong-li,YANG Xiao-hua,et al.Research on Microstructure of Crude Coarse Grain Saline Soil under Freezing and Thawing Cycles[J].Rock&Soil Mechanics,2010,31(1):123-127.
[17]任秀玲,张文,刘昕,等.西北地区盐渍土盐胀特性研究进展与思考[J].土壤通报,2016,47(1):246-252.REN Xiu-ling,ZHANG Wen,LIU Xin,et al.The Research Development and Thinking about the Expansibility Property of Saline Soil in Northwest Region[J].Chinese Journal of Soil Science,2016,47(1):246-252.
[18]万旭升,廖孟柯,杜立群.温度对硫酸钠盐渍土盐胀影响的试验研究[J].公路交通科技,2016,33(8):44-50.WAN Xu-sheng,LIAO Meng-ke,DU Li-qun.Experimental Study on Influence of Temperature on Salt Expansion of Sodium Sulfate Saline Soil[J].Journal of Highway and Transportation Research and Development,2016,33(8):44-50.
[19]杨鹏,朱彦鹏,曹亚鹏,等.含水率单次递减条件下粗颗粒硫酸盐渍土盐胀的室内模拟试验[J].岩土力学,2017,38(10):2909-2915.YANG Peng,ZHU Yan-peng,CAO Ya-peng,et al.Experiment of Salt Expansion Behavior for Coarse Saline Soil Containing Sulphate due to Drying[J].Rock and Soil Mechanics,2017,38(10):2909-2915.
[20]刘凯,张远芳,张运海,等.冻融循环条件下亚氯盐渍土盐冻胀试验研究[J].长江科学院院报,2018,35(5):93-96,102.LIU Kai,ZHANG Yuan-fang,ZHANG Yun-hai,et al.Salt Heaving Test of Sub-chlorine Saline Soil under Cyclic Freezing and Thawing[J].Journal of Yangtze River Scientific Research Institute,2018,35(5):93-96,102.
[21]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.NIU Xi-rong,GAO Jiang-ping.Expression for Volume Change of Sulphate Saline Soil Considering Salt Expansion and Frost Heave[J].Chinese Journal of Geotechnical Engineering,2015,37(4):755-760.
[22]YANG P,LIU Y F,MI H Z,et al.Study on Deformation Property of Coarse Particles(Sulfate)Saline Soil with Field Test[J].Applied Mechanics&Materials,2014,580-583:329-333.
[23]杨晓华,王永威,张莎莎.基于调节因素的盐渍土盐胀率随含水率变化规律研究[J].中国公路学报,2016,29(10):12-19.YANG Xiao-hua,WANG Yong-wei,ZHANG Sha-sha.Research on Changing Rules of Salt Expansion Rate of Salty Soil with Water Content Based on Regulation Factor[J].China Journal of Highway and Transport,2016,29(10):12-19.
[2]FUJIMAKI H,SHIMANO T,INOUE M,et al.Effect of A Sulfate Crust on Evaporation from a Bare Saline Soil[J].Vadose Zone Journal,2006,5(4):1246-1256.
[3]马晓宁,王选仓,孙进玲,等.陇南地区膨胀土微观结构与膨胀性[J].南水北调与水利科技,2016,14(3):111-114,149.MA Xiao-ning,WANG Xuan-cang,SUN Jin-ling,et al.Microstructure and Expansion Properties of Expansive Soil in Longnan District[J].South-to-North Water Transfers and Water Science&Technology,2016,14(3):111-114,149.
[4]LAI Y,LIAO M,HU K.A Constitutive Model of Frozen Saline Sandy Soil Based on Energy Dissipation Theory[J].International Journal of Plasticity,2016,78:84-113.
[5]MA Q,LAI Y,ZHANG M,et al.Model Test Study on The Anti-saline Effect of the Crushed-rock Embankment with Impermeable Geotextile in Frozen Saline Soil Regions[J].Cold Regions Science&Technology,2017,141:86-96.
[6]ZHANG Y,YANG Z,LIU J,et al.Impact of Cooling on Shear Strength of High Salinity Soils[J].Cold Regions Science&Technology,2017,141:122-130.
[7]张莎莎,杨晓华,戴志仁.基于均匀设计的砾类硫酸盐渍土盐胀特性试验研究[J].公路交通科技,2009,26(5):29-34.ZHANG Sha-sha,YANG Xiao-hua,DAI Zhi-ren.Experimental Study on Salt Expansion of Gravel Sulfate Salty Soil Based on Uniform Design[J].Journal of Highway and Transportation Research and Development,2009,26(5):29-34.
[8]温小平,翁兴中,张俊,等.道面基层抗硫酸盐侵蚀性能及防范措施[J].公路交通科技,2015,32(9):36-40.WEN Xiao-ping,WENG Xing-zhong,ZHANG Jun,et al.Characteristics of Sulfate Corrosion Resistance of Pavement Base and Precaution Measures[J].Journal of Highway and Transportation Research and Development,2015,32(9):36-40.
[9]王智远,张宏,张海龙.硫酸盐盐渍化道路横向隆起的力学响应分析[J].公路交通科技,2018,35(8):1-6,54.WANG Zhi-yuan,ZHANG Hong,ZHANG Hai-long.Analysis on Mechanical Response of Transverse Uplift of Sulphate Salinized Pavement[J].Journal of Highway and Transportation Research and Development,2018,35(8):1-6,54.
[10]谢宇晨,翁兴中,张俊,等.盐渍土地区道面混凝土盐冻侵蚀研究[J].公路交通科技,2017,34(4):25-31.XIE Yu-chen,WENG Xing-zhong,ZHANG Jun,et al.Study on Salt-frost Erosion of Pavement Concrete in Salty Soil Area[J].Journal of Highway and Transportation Research and Development,2017,34(4):25-31.
[11]温小平,翁兴中,张俊,等.新疆地区粗颗粒盐渍土毛细水上升和隔断层隔断效果研究[J].公路交通科技,2015,32(5):56-60,67.WEN Xiao-ping,WENG Xing-zhong,ZHANG Jun,et al.Research on Effect of Capillary Water Rise and Layer Separation of Coarse Grained Salty Soil in Xinjiang Region[J].Journal of Highway and Transportation Research and Development,2015,32(5):56-60,67.
[12]陈渊召,李振霞.盐渍土工程性质试验[J].公路交通科技,2012,29(12):1-6,13.CHEN Yuan-zhao,LI Zhen-xia.Experiment of Engineering Property of Saline Soil[J].Journal of Highway and Transportation Research and Development,2012,29(12):1-6,13.
[13]牛玺荣,李志农,高江平.盐渍土盐胀特性与机理研究进展[J].土壤通报,2008,39(1):163-168.NIU Xi-rong,LI Zhi-nong,GAO Jiang-ping.Study Progress in Salt Expansion Characteristic and Mechanism of Saline Soil[J].Chinese Journal of Soil Science,2008,39(1):163-168.
[14]包卫星,李志农,罗炳芳.公路工程粗粒盐渍土易溶盐试验方法研究[J].岩土工程学报,2010,32(5):792-797.BAO Wei-xing,LI Zhi-nong,LUO Bing-fang.Test Method for Soluble Salt in Saline Soil in Highway Engineering[J].Chinese Journal of Geotechnical Engineering,2010,32(5):792-797.
[15]包卫星,张莎莎.路用砂类盐渍土盐胀及融陷特性试验研究[J].岩土工程学报,2016,38(4):734-739.BAO Wei-xing,ZHANG Sha-sha.Experimental Study on Salt Expansion and Thawing Subsidence Properties of Sandy Saline Soil[J].Chinese Journal of Geotechnical Engineering,2016,38(4):734-739.
[16]张莎莎,谢永利,杨晓华,等.典型天然粗粒盐渍土盐胀微观机制分析[J].岩土力学,2010,31(1):123-127.ZHANG Sha-sha,XIE Yong-li,YANG Xiao-hua,et al.Research on Microstructure of Crude Coarse Grain Saline Soil under Freezing and Thawing Cycles[J].Rock&Soil Mechanics,2010,31(1):123-127.
[17]任秀玲,张文,刘昕,等.西北地区盐渍土盐胀特性研究进展与思考[J].土壤通报,2016,47(1):246-252.REN Xiu-ling,ZHANG Wen,LIU Xin,et al.The Research Development and Thinking about the Expansibility Property of Saline Soil in Northwest Region[J].Chinese Journal of Soil Science,2016,47(1):246-252.
[18]万旭升,廖孟柯,杜立群.温度对硫酸钠盐渍土盐胀影响的试验研究[J].公路交通科技,2016,33(8):44-50.WAN Xu-sheng,LIAO Meng-ke,DU Li-qun.Experimental Study on Influence of Temperature on Salt Expansion of Sodium Sulfate Saline Soil[J].Journal of Highway and Transportation Research and Development,2016,33(8):44-50.
[19]杨鹏,朱彦鹏,曹亚鹏,等.含水率单次递减条件下粗颗粒硫酸盐渍土盐胀的室内模拟试验[J].岩土力学,2017,38(10):2909-2915.YANG Peng,ZHU Yan-peng,CAO Ya-peng,et al.Experiment of Salt Expansion Behavior for Coarse Saline Soil Containing Sulphate due to Drying[J].Rock and Soil Mechanics,2017,38(10):2909-2915.
[20]刘凯,张远芳,张运海,等.冻融循环条件下亚氯盐渍土盐冻胀试验研究[J].长江科学院院报,2018,35(5):93-96,102.LIU Kai,ZHANG Yuan-fang,ZHANG Yun-hai,et al.Salt Heaving Test of Sub-chlorine Saline Soil under Cyclic Freezing and Thawing[J].Journal of Yangtze River Scientific Research Institute,2018,35(5):93-96,102.
[21]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.NIU Xi-rong,GAO Jiang-ping.Expression for Volume Change of Sulphate Saline Soil Considering Salt Expansion and Frost Heave[J].Chinese Journal of Geotechnical Engineering,2015,37(4):755-760.
[22]YANG P,LIU Y F,MI H Z,et al.Study on Deformation Property of Coarse Particles(Sulfate)Saline Soil with Field Test[J].Applied Mechanics&Materials,2014,580-583:329-333.
[23]杨晓华,王永威,张莎莎.基于调节因素的盐渍土盐胀率随含水率变化规律研究[J].中国公路学报,2016,29(10):12-19.YANG Xiao-hua,WANG Yong-wei,ZHANG Sha-sha.Research on Changing Rules of Salt Expansion Rate of Salty Soil with Water Content Based on Regulation Factor[J].China Journal of Highway and Transport,2016,29(10):12-19.