An experimental investigation on strength characteristics of fiber-reinforced clayey soil treated with lime or cement

Abstract

This paper presents an experimental investigation on the strength properties of fiber-reinforced clayey soil stabilized with lime or cement at lower content (5% by weight) cured for 28 days. A series of consolidated undrained (CU) triaxial compression tests and unconfined compressive (UC) strength tests were conducted on compacted untreated, lime-treated and cement-treated clayey soil specimens reinforced with different polyester fiber content (i.e., 0%, 0.05%, 0.1%, 0.2% by weight) to evaluate the effect of fiber content on the strength behavior of tested soil. Test results indicated that the addition of lime or cement gave a significant increase in strength and strength parameters at a certain fiber content, where the improvement effect of cement is better than that of lime. Strain-softening curves were obtained for lime-treated or cement-treated fiber-reinforced specimens compared with the strain-hardening for fiber-reinforced ones. The residual strength is about 75% on average the peak strength for fiber and lime-treated specimens compared to about 50% decrease of peak strength for fiber and cement-treated specimens. The stress and strain curve for the specimen with higher fiber content lies above on that with lower fiber content. Fiber-reinforced plain soil showed a ductile failure mode compared with brittle failure mode for lime or cement-treated specimen. The values of undrained shear strength, unconfined compressive strength, cohesion and internal friction angle of plain soil and lime-treated soil followed the same increase trend when the polyester fiber content increased from 0% to 0.2%. While for lime-treated soil specimens, peak values can be observed when the fiber content was 0.1%. It is recommended to use the optimum fiber content to achieve a better improvement effect in the engineering applications.