Document Type : Research Article
Civil Engineering department, Engineering Faculty, Kermanshah University of Technology (KUT), Kermanshah, Iran
Civil Engineering Department, Bu-Ali Sina University, Hamedan, Iran
The occurrence of ice caps and the subsequent melting of the ice causes great damage to the substrates consisting of fine-grained soils every year. However, the volumetric changes of soil during freezing-thawing is a factor that reduces strength and increases deformations. In this study, several laboratory measurements are presented to investigate the effects of freeze-thaw cycles on the behavior of cylindrical sand specimens. To investigate the effects of freezing, fine-grained sand has been selected. At the same time, the methods of chemical stabilization of soil by mixing with cement with amounts of 2, 4 and 6% by weight of dry soil and mechanical reinforcing by adding 0, 0.5 and 1% by weight of recycled DTY fibers are included in the agenda of the article. This study shows that the presence of fibers next to cement causes obvious changes in the stiffness, strength and durability characteristics of the samples under the effect of freeze-thaw cycles. In 7-days dry samples , the compressive strength of the samples increases with the addition of fibers. In the 28-days samples, with an increase of only 0.5% of fibers with a length of 0.5 cm, the increase in the unconfined compressive strength was gained and its decrease was observed after that. In all 7 and 28 days dry samples, the strength of the samples decreases with the increase of fiber size from 0.5 cm to 1.5 cm. Also, by adding the percentage of fibers from 0.5 to 1%, the trend of decreasing strength can be seen.