自然科学版 英文版
自然科学版 英文版
自然科学版 英文版
自然科学版 英文版
英文版编委
自然科学版 英文版
英文版首届青年编委

您目前所在的位置:首页 - 期刊简介 - 详细页面

中南大学学报(英文版)

Journal of Central South University

Vol. 27    No. 7    July 2020

[PDF Download]    [Flash Online]

    

Swelling characteristics of East-Africa black cotton soil based on computer molecular simulation
ZHU Jun-qing(朱俊清)1, ZHANG Wei-guang(张伟光)1, ZHANG Yu-qing(张裕卿)2, 3, TANG Hao(唐皓)1

1. School of Transportation, Southeast University, Nanjing 210096, China;
2. National Engineering Laboratory of Highway Maintenance Technology, Changsha University of Science & Technology, Changsha 410114, China;
3. Aston Institute of Materials Research, Engineering Systems & Management Group, Aston University,Birmingham, B4 7ET, UK

Abstract:Black cotton soil in East Africa is not a stable engineering material for highway and railroad projects. Its strong swelling potential when it absorbs water causes distresses in subgrade of highway and railroad, and thus leads to failures of the projects. This paper presents study on the swelling characteristics of black cotton soil in East Africa. Lab tests were conducted to obtain its basic engineering properties, and the results show that black cotton soil contains high amount of montmorillonite and exchangeable cations and is strong expansive soil. Molecular modelling was exploited to further investigate water absorption ability of montmorillonite. Three different molecular models of montmorillonite were constructed and used for simulations, among which Types I and II montmorillonite represent the expansive soil montmorillonite in China, and Types II and III montmorillonite represent black cotton soil montmorillonite in East Africa. The results showed that the interlayer cations of Type III montmorillonite possessed the strongest water absorption ability based on analysis of radial distribution function (RDF) of cations. Interlayer compensatory cations of Na+ enhance the hydration ability of the other major cations, thus resulting in the strong swelling potential of East-Africa black cotton soil.

 

Key words: East-Africa black cotton soil; swelling characteristics; montmorillonite; molecular simulation; free swell index

中南大学学报(自然科学版)
  ISSN 1672-7207
CN 43-1426/N
ZDXZAC
中南大学学报(英文版)
  ISSN 2095-2899
CN 43-1516/TB
JCSTFT
版权所有:《中南大学学报(自然科学版、英文版)》编辑部
地 址:湖南省长沙市中南大学 邮编: 410083
电 话: 0731-88879765(中) 88836963(英) 传真: 0731-88877727
电子邮箱:zngdxb@csu.edu.cn 湘ICP备09001153号