岩土工程学报2026，Vol.48Issue(4)：740-748,9.DOI:10.11779/CJGE20250030
膨润土缓冲层材料热传导特性的高温劣化效应
Deterioration effect on thermal conductivity of bentonite as buffer material in hype-temperature conditions
摘要
Abstract
To investigate deterioration effect on thermal conductivity of bentonite as a buffer material in hype-temperature conditions,the bentonite powder is pretreated at different thermal aging temperatures(T=25,100,150,200℃).The thermal conductivity of compacted bentonite samples after pretreatment is measured by thermal probe method,and the effect of temperature T on thermal conductivity λ is discussed.Based on the tests of laser particle size analysis,X-ray diffraction and thermogravimetric analysis,the microscopic mechanism of the effect of temperature T on the λ of bentonite samples is revealed.The results show that the λ of bentonite decreases gradually with the increase of temperature T,and the maximum decrease is 6.99%.The λ-T curve of the samples shows a piecewise decreasing trend with T=100℃as the boundary point,and the deterioration effect of λ is more significant under high temperatures(100～200℃).The essential reason for the aforementioned changes is that when T≤100℃(25～100℃),the temperature effect is predominantly manifested through the desorption of the free and weakly bound water,the thinning of the bound water film,the reduction of the particle size of bentonite,resulting in the reduction of the solid phase volume and the increase of the gas phase volume in the samples,which leads to the λ decreases.When T>100℃(100～200℃),the above temperature effect is further intensified and further reduces the particle size of the soil.On the other hand,the high temperature causes the part of montmorillonite to transform into mica sodium with high density and water absorption and low λ,resulting in a more obvious reduction of λ in the sample.关键词
MX80膨润土/导热系数/高温劣化/微观机理/激光粒度分析Key words
MX80 bentonite/thermal conductivity/temperature deterioration/micro-mechanism/laser particle size analysis分类
建筑与水利引用本文复制引用
曾召田,林铭宇,吕海波,范理云,曹珊珊,任天翔..膨润土缓冲层材料热传导特性的高温劣化效应[J].岩土工程学报,2026,48(4):740-748,9.基金项目
国家自然科学基金项目(42167020) （42167020）
广西自然科学基金项目(2023GXNSFAA026187) （2023GXNSFAA026187）
广西研究生教育创新计划项目(YCSW2024360)This work was supported by the National Natural Science Foundation of China(Grant No.42167020),the National Natural Science Foundation of Guangxi(Grant No.2023GXNSFAA026187)and Guangxi Postgraduate Education Innovation Program Project(Grant No.YCSW2024360). （YCSW2024360）
