Effect of nano-MgO on mechanical performance of cement stabilized silty clay

Abstract

A series of direct shear tests were performed on cement-admixed silty clay to investigate the effect of cement content and nano-magnesia (MgO) on its shear strength properties. For each normal stress, shear strength increased with cement content. However, an obvious increment in shear strength was achieved when the cement content was adjusted from 13% to 17%. Both cohesion and friction angle of cemented soil increased with cement content, and exponential function was adopted to correlate both the factors with cement content. For cement content of 10% investigated in this study, the optimum nano-MgO content was 10‰, wherein the cohesion could reach the peak value. The microstructure of the mixture revealed that the structure of the mixture was compacted for the optimum nano-MgO content. However, micro-cracks were formed when the amount of nano-MgO exceeded its optimum content.

Key Words:

• Cement
• nano-MgO
• shear strength
• silty clay

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work is supported by the National Natural Science Foundation of China (grant number 41772311), Zhejiang Provincial Natural Science Foundation of China (grant number LY17E080016), and Open Research Fund of State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Science (grant number Z017013).