*2.2. Fiber*

Two types of fibers FM 300 and FC 500 supplied by Propex operating company (Chattanooga, TN, USA) were used for the present study. The physicochemical properties of two fibers are provided in Table 2. The length of fiber adopted for the experimental work is 6 mm and 12 mm for both FM and FC (Figure 1); the dosage of each fiber is fixed at 0.2% and 0.6% by weight of dry soil mass.

**Table 2.** Physicochemical properties of fibers.


**Figure 1.** Fibers used in the study.
