Waste tires are extensively being used in civil engineering applications to improve flexibility and elastic properties of the base foundation material. Moreover, by using pure tires or soil-tire mixtures, rubber stockpiles which cause lots of environmental contaminations are being consumed. The objective of this research is to study the strength and modulus variations of sands when combined with rubber materials in different sizes and percentages. To this reason, triaxial experiments were performed on various sand-rubber mixtures using static triaxial apparatus. Samples were constructed at the maximum dry density and optimum moisture content to consider engineering applications in dry regions. The results show that rubber content and rubber-sand particle size ratio,D50,r/D50,s, significantly affect the mixture behavior in the manner which increase in the former and decrease in the latter leads to more softening behavior. Furthermore, specific combination of sand and rubber which may improve the elastic properties of the mixture is proposed as a base flexible layer.