摘要
为研究高温受热对膨润土物理性能的影响,将MX-80膨润土粉末置于4种不同温度(25、100、150、200℃)下受热30 d后,对其进行比重、界限含水率、膨胀指数试验。在此基础上,利用热重分析试验(TGA)和X射线衍射试验(XRD)揭示高温受热后MX-80膨润土的物理性能变化及微观机理。试验结果表明:MX-80膨润土的比重、界限含水率、膨胀指数均随受热温度增加而减小,100℃以下受热时温度对膨润土物性的影响较小,在150℃及以上受热时对物性指标的影响较大;受热30 d后MX-80膨润土中蒙脱石含量减少,150、200℃下受热后出现了新矿物钠云母,表明受热温度达到150℃后土中出现了蒙脱石向钠云母的转化;受热后MX-80膨润土吸附的弱结合水、强结合水含量减少;MX-80膨润土物理性能的变化可归因于不同高温作用后土中蒙脱石向钠云母的转化和结合水的脱附。
To study the effect of high temperature heating on the physical properties of bentonite,MX-80 bentonite powder was subjected to 4 different temperatures(25,100,150,200℃)under heating for 30 days.The variations of physical properties such as specific gravity,limit water content and swell index of MX-80 bentonite were studied.On this basis,thermogravimetric analysis(TGA)test and X-ray diffraction(XRD)test were carried out to reveal the changes of physical properties and the microscopic mechanism of the MX-80 bentonite after being heated at high temperature.The experiment results show that the physical indicators(specific gravity,limit water content,swell index)of MX-80 bentonite decreases with the increase of heating temperature.The temperature below 100℃has little effect on the physical properties of bentonite,while the temperature at 150℃and above has greater effects on the physical properties.After being heated for 30 days,the montmorillonite content of MX-80 bentonite decreases,and a new mineral paragonite appears after being heated at 150℃and 200℃respectively,indicating the transformation of montmorillonite to paragonite in the soil after reaching a heating temperature of 150℃.After heating,the content of weakly bound water and strongly bound water absorbed by MX-80 bentonite decreases.The changes in the physical properties of MX-80 bentonite can be attributed to the transformation of montmorillonite to paragonite and the desorption of bound water in MX-80 bentonite after different temperature treatments.
作者
陈梦豪
付海
曹珊珊
林铭宇
陈良宇
CHEN Meng-hao;FU Hai;CAO Shan-shan;LIN Ming-yu;CHEN Liang-yu(Guilin University of Technology,Guilin 541004,China;Hebei Haichuang Geotechnical Engineering Co.,Ltd.,Tangshan 063009,China)
出处
《金陵科技学院学报》
2024年第1期46-53,共8页
Journal of Jinling Institute of Technology
基金
国家自然科学基金地区项目(41962014)
广西自然科学基金项目(2023GXNSFAA026187)
大学生创新创业项目(202310596316)。
关键词
温度
MX-80膨润土
物理性能
蒙脱石
结合水
钠云母
temperature
MX-80 bentonite
physical property
montmorillonite
bound water
paragonite
