Effect of Freeze-Thaw on Compressive Strength of Clayey Soils Reinforced with Wool

Abstract

ABSTRACT Reinforcing clayey soil using synthetic and natural fibers has been widely used as soil improvement methods in recent years. The usage of wool, which is inside the natural fibers, as a reinforcing material is seen as an economic, sustainable, and environmentally friendly solution. The compressive strength parameters of clayey soils (CS) equipped with wool were determined by a series of free pressure strength tests before and after freeze-thaw (F-T). The F-T cycle was repeated 12 times in cycles 1, 7, and 28 days. The highest strength increase was attained after 28 days of curing. The compressive strength increase of CS samples prepared with four different wool additives (0.5%, 1%, 1.5%, and 2% dry weight) occurred between 16.9–68.7% and 13.3–62.7% before and after F-T, respectively. The highest compressive strength increase before and after F-T occurred in CS+1.5% wool mixture. In addition, the wool ratio and the number of freeze-thaw cycles were determined to be important parameters in the increase in compressive strength. In summary, it is concluded that wool-supported CS can be used in the basic design of engineering structures and in shallow depths especially in regions with cold climates.