Document Type : Research Article
civil engineering department, faculty of engineering, yazd university
The presence of organic matter in soil reduces its compressive and shear strength. It is, therefore, not suitable for construction projects. Soil strength can be enhanced by various methods. Stabilization and reinforcement are two common ways of improving soil strength parameters. In this study, the effect of polypropylene fibers on stabilized soil was investigated. For this purpose, lime and xanthan gum biopolymer were used as stabilizers, and soil was reinforced with polypropylene fibers. The experiments were performed using 1 and 3% lime, 1 and 1.5% xanthan gum biopolymer, and 0.5% polypropylene fibers (by dry weight). To investigate the effect of these materials on soil strength, uniaxial compression strength and indirect tensile strength tests were conducted. The processing time of the samples was 7 and 21 days. The results showed that the addition of lime, xanthan gum biopolymer, and polypropylene fibers can increase the compression strength of the soil. Increasing the processing time can also increase the strength of stabilized soil, and the addition of fibers leads to the improvement of soil ductility. The maximum tensile strength was observed in the sample stabilized with xanthan gum biopolymer. In the soil sample with 1% lime, the addition of fibers could increase the soil tensile strength. The results suggest that soil strength parameters can considerably be improved if xanthan gum is replaced with lime. In addition, this material is environment-friendly.