The objective is to develop new civil engineering applications that will free the environment from a large quantity of used tires. The present work consists of mixing rubber aggregates with sand to improve the mechanical behavior of soils. The study was carried out on Hostun sand mixed with proportions by weight of rubber aggregates between 0 and 30%.The experimental protocol followed consisted in determining the variations of the maximum and minimum void ratios of the mixtures versus the percentage of rubber aggregates. Direct shear tests were carried out on sand-rubber mixtures at relative densities of 55 and 95% and at normal stresses of 100, 200 and 400 kPa. Based on the results of the experimental data, the following conclusions were obtained: the maximum and minimum void ratios decrease with increasing rubber content up to 60% and then increase again. It is also shown that the shear strength of sand increases with increasing rubber content. The shear strength of the mixtures for the two relative densities of 55% and 95% is maximal for a content of 20% of the rubber aggregates. It also increases with the increase of the normal stress applied and with the increase of the relative density.