|Table of Contents|

Experimental study on mechanical properties of loess improved by nano clays(PDF)

《建筑科学与工程学报》[ISSN:1673-2049/CN:61-1442/TU]

Issue:
2023年02期
Page:
138-149
Research Field:
岩土工程
Publishing date:

Info

Title:
Experimental study on mechanical properties of loess improved by nano clays
Author(s):
CAO Baohua1; 2;  ZHAO Danni1;  XU Jiangbo1;  SUN Haohui1;  QI Yu1;  LAI Jie3
(1. School of Highway, Chang'an Unversity, Xi'an 710064, Shaanxi, China; 2. Xi'an Changda Highway Engineering Inspection Center Co., Ltd, Xi'an 710064, Shaanxi, China; 3. Combat Support College, Rocket Force University of Engineering, Xi'an 710025, Shaanxi, China)
Keywords:
attapulgite;  nano montmorillonite;  unconfined compressive strength;  shear strength;  modified loess
PACS:
TU472
DOI:
10.19815/j.jace.2021.10016
Abstract:
Two different nano clay materials were mixed into the loess soil in the Ansai area of Shaanxi Province, and an orthogonal test was designed to investigate the effects of different factors, such as mixing ratio, water content, and curing time on the modified loess. Three-axis tests were conducted to analyze the changes in the unconfined compressive strength and shear strength of the modified loess after mixing the attapulgite and nano montmorillonite, and the improvement mechanisms were microscopically analyzed by SEM. The results show that the addition of 1% attapulgite and 2% nano montmorillonite have the most significant influence on the compressive strength of the loess. Under certain water content, the compressive strength of the plain loess increase by 21% and 42.3%, respectively. The stress-strain curve of the modified loess with the two types of nano clay is affected by dry density, confining pressure, and mixing ratio. The modified loess with a dry density of 1.35 g?cm-3 and a confining pressure of 50 kPa exhibit a strain softening phenomenon, while the stress-strain curves of the modified loess at four different confining pressures show strain hardening tendency when the dry density reached 1.65 g?cm-3. The two types of nano clay significantly affect the shear strength index of the modified loess. The addition of 1% attapulgite and 2% nano montmorillonite increase the cohesion of the modified loess by 61.02% and 81.70%, respectively, and the internal friction angle increase by 27.86% and 21.31%, respectively.

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Last Update: 2023-03-20