Effect of waste tire cord reinforcement on unconfined compressive strength of lime stabilized clayey soil under freeze–thaw condition

Mechanical properties of fine grained soils, which are subjected to freeze–thaw condition, often change considerably, so when these soils are used as a part of a structure or as an infrastructure, determining a proper solution is necessary. In this paper, stabilization and fiber reinforcement are simultaneously examined as a soil modification method. A series of unconfined compression tests was carried out to investigate the effects of tire cord waste products on mechanical characteristics of a lime stabilized and unstabilized clayey soil subjected to freezing and thawing cycles. Several specimens were prepared at three percentages of lime (i.e. 0%, 4%, and 8%) and four percentages of discrete short nylon fiber (i.e. 0%, 0.5%, 1%, and 1.5%) by weight of dry soil. The samples were saturated and exposed to one up to three freeze–thaw cycles before testing. The results indicated that the compressive strength and stress–strain behavior of specimens depend considerably on the amounts of both fiber and lime. For stabilized specimens, the reinforcement effect of fiber was more than unstabilized ones and also, by inclusion of fiber, 4% lime stabilized specimens indicated more strength in comparison to the untreated and 8% lime stabilized specimens. Furthermore, the contribution of fiber in the strength of samples increased as the number of freeze–thaw cycles was increased.