长江科学院院报2019，Vol.36Issue(4)：140-144,150,6.DOI:10.11988/ckyyb.20180925
弱膨胀土在浸水膨胀过程中的微观结构变化特征
Microstructural Variation Characteristics of Weak Expansive Soils During Hydration
摘要
Abstract
One-dimensional swelling tests under different load conditions were conducted to obtain the evolution of Nanyang expansive soil’s microstructure. Samples with initial state and samples swelling under different conditions were freezing-dried to get prepared for Scanning Electron Microscope ( SEM) tests and Mercury Intrusion Porosime-try ( MIP) test. Then the modification in microstructures and pore size distribution were analyzed. SEM tests show that soil-particle arrangement has no obvious directionality. Samples with initial compacted state and swelling under constant volume are in turbulent flow structures, while samples swelling under 0 or 50 kPa surcharge are of granular structures after reaching steady state. MIP test shows that the pore size distribution curves of samples under different swelling conditions are of three peaks. Pores in soils can be classified into macro-pore, fine-pore, micro-pore and ultra-micro-pore. Compared with initial states, fine-pores in samples swelling under constant volume are compressed into micro-pore. The volumes of all kinds of pores in samples swelling under 0 or 50 kPa surcharge loads all in-crease as the surcharge loads are larger than the expansive force. In this situation, soil particles can push each other away.关键词
弱膨胀土/微观结构/孔隙分布/一维膨胀/压汞试验/扫描电镜试验Key words
weak expansive soil/ microstructure/ pore size distribution/ one-dimensional swelling/ MIP/ SEM分类
建筑与水利引用本文复制引用
陈宝,潘燕敏,路晓军,喻达..弱膨胀土在浸水膨胀过程中的微观结构变化特征[J].长江科学院院报,2019,36(4):140-144,150,6.基金项目
国网河南电网项目(5217L0160001) （5217L0160001）
