湖南大学学报（自然科学版）2026，Vol.53Issue(3)：99-107,9.DOI:10.16339/j.cnki.hdxbzkb.2026028
干湿循环下膨胀土纳米尺度微观结构演化的小角中子散射研究
Small-angle neutron scattering study of nanoscale microstructural evolution of expansive clay under drying-wetting cycling
摘要
Abstract
The evolution of nanoscale microstructure of expansive clay during drying-wetting cycling significantly affects their macroscopic hydro-mechanical properties.Due to limitations in testing scope and accuracy,the existing test methods are difficult to quantitatively characterize the nanoscale microstructural evolution of expansive clay.In this paper,the first attempt is made to quantitatively characterize the nanoscale microstructural evolution of expansive clay during drying-wetting cycling using small-angle neutron scattering technique.The results show that the microstructural pore size distribution of expansive clay exhibits bimodal characteristics in the range of 2~100 nm,corresponding to inter-sub-stack pores and inter-particle pores,respectively.For the whole drying-wetting cycling,the overall volumetric strain of these two types of microstructures increases by about 11%and decreases by about 10%during drying and wetting process.Among them,the inter-sub-stack pore variations dominate the microstructure volume changes in this detection range.Comparative analysis of the neutron scattering test results and the isothermal adsorption physical model shows that the potential physical inducement of the volume deformation inter-sub-stack pores is external adsorption.This study reveals the microscopic mechanisms by which drying-wetting cycling affects the hydraulic conductivity,swelling,and shear strength of soils,providing a theoretical basis for the regulation and improvement of expansive soil microstructure.关键词
小角中子散射/膨胀土/纳米尺度微观结构/干湿循环/土-水相互作用Key words
small-angle neutron scattering/expansive clay/nanoscale microstructure/drying-wetting cy-cling/soil-water interaction分类
建筑与水利引用本文复制引用
张超,宜小磊,苟凌云,柯于斌,郭帅成..干湿循环下膨胀土纳米尺度微观结构演化的小角中子散射研究[J].湖南大学学报（自然科学版）,2026,53(3):99-107,9.基金项目
国家重点研发计划项目(2024YFC3809000),National Key R&D Program Project of China(2024YFC3809000) （2024YFC3809000）
国家自然科学基金资助项目(52078208,52090083),National Natural Science Foundation of China(52078208,52090083) （52078208,52090083）
