Experimental Investigation of Unconfined Compression Strength and Stiffness of Cement Treated Salt-Rich Clay

摘要

Soft clay with high sodium chloride salt concentration is a problem encountered by geotechnical and highway engineers. Chemical stabilization using cement is an attractive method to improve the engineering properties of soft soil. However, very limited studies have been conducted to reveal the effect of salt concentration on the engineering properties of cement-stabilized soil and the reported results in literature are not consistent. The impact of sodium chloride salt on the strength and stiffness properties of cement-stabilized Lianyungang marine clay is studied in this study. The clay with various sodium chloride salt concentrations was prepared artificially and stabilized by various contents of Ordinary Portland cement. A series of unconfined compressive strength (UCS) tests of cement stabilized clay specimen after 7, 14, and 28 days curing periods were carried out. Tlie results indicate that a high sodium chloride salt concentration has a detrimental effect on the UCS and stiffness of cement-stabilized clay. The detrimental effect of salt concentration on the strength and stiffness of cement-stabilized clay directly relates to cement content. Soils mixed with high cement content are more resistant to the negative effect of salts than soils mixed with low cement content. The ratio of modulus of elasticity to UCS of cement treated soil does not have an obvious relationship with salt concentration. The findings of this study present a rational basis for the understanding of the impact of salt on the engineering properties of cement-treated soil.