IntroductionBy the advancement of human societies and the increasing use of vehicles, millions rings of scrap tires around the world is taking out of the consumption cycle and collecting as garbage every year. Due to the high volume of scrap tires, dangerous fires occurrence, and the high cost of hygiene disposal, this issue has become one of the biggest environmental problems. Therefore, providing some solutions to this problem seems to be necessary. Some of the solutions are reusing them as filler materials in construction projects, such as road construction, retaining walls, and drainage systems. Over the past two decades, several studies have been conducted about the application of crumb rubber in the reinforcement of retaining earth walls and also about its use as filler materials in the road construction [1][2][3]. In addition to using crumb rubber in geotechnical projects, it is important to pay attention to possible environmental pollutions caused by these material types. For this reason, many experimental and field studies have been performed on the environments and fluids which are placed next to these materials. The obtained results show that no harmful effect is relevant and the only environmental limitation in the use of crumb rubber is related to their self-ignition potential [1][2][3][4]. In1998, the ASTM regulation provided the D6270 instruction to decrease this potential. Foose et al. (1996) investigated the behavior of sand reinforced by scrap tire chips with direct shear tests. The results of this research have illustrated that in all the cases, the addition of tire chips has caused an increase in the internal friction angle [5]. Lee et al (1999) investigated the use of tire chips as a light weight material. Triaxial test results and theoretical studies on the finite element method showed that there is a linear relationship between the deviator stress and axial strain of rubber components and chips [2]. Yoon et al (2004) studied bearing capacity and settlement of sand reinforced with crumb rubber by conducting plate load tests. The results of that research showed that the bearing capacity of the loose sand reinforced with scrap tire chips is 2 times more than the bearing capacity of loose sand. The settlement decrease caused by reinforcing the sand with the mixture of brick fragments and tire chips has been more than 70% for