Effects of Xanthan Gum and Lime on Physical Properties and Mechanical Behavior of Organic Soil

A sample of organic soil collected from the Chaharmahal-Bakhtiari Province, Iran, was treated with ۰.۵, ۱, ۱.۵, ۲, ۲.۵, and ۳% of xanthan gum and ۱, ۳, and ۵% of lime. The untreated and the treated specimens were subjected to physical and mechanical tests, including soil classification, pH measurement, compaction test, unconfined compressive strength test, indirect tensile test, and direct shear test. An increase in lime by ۳% led to the greatest increase in the compressive strength (۵ and ۶ times for the ۷-day and ۲۱-day samples, respectively) and the tensile strength (۳.۷ and ۴.۵ times for the ۷-day and ۲۱-day samples, respectively). Xanthan gum also improved the compressive strength (۳ and ۶ times for the ۷-day and ۲۱-day samples, respectively) and the tensile strength (۵.۹ and ۷.۵ times for the ۷-day and ۲۱-day samples, respectively). Increasing lime up to ۳% enhanced the adhesion of the stabilized soil for ۳.۵ and ۷.۵ times that of the organic soil for ۷ and ۲۱ days of curing, respectively. Also, the friction angle increased by ۴۰%  and ۶۸% times with the increase of lime up to ۳% during ۷ and ۲۱ days of curing, respectively. Stabilization with xanthan gum led to ۱۱.۵ and ۱۷.۵ times increase adhesion for ۷-day and ۲۱-day samples, respectively. Moreover, xanthan gum increased the friction angle by ۴۷% and ۷۵% for ۷-day and ۲۱-day samples, respectively. The findings generally suggest that xanthan gum can be a good ecofriendly alternative to lime as a soil stabilizer.

کلیدواژه ها:

Organic soil ، Soil stabilization ، Xanthan gum biopolymer ، lime ، Shear strength parameters