As the number of waste tires increases due to the increase in the number of vehicles, it is necessary to benefit from the material out of which tires are made, and this poses a real challenge. The purpose of this paper is to investigate the impact of using the rubber of waste tires (10 years of age) in an asphalt mix design (3/4" wearing course). The crumb (shredded) rubber is used with (60/70) bitumen grade. Four different percentages of rubber are used with bitumen: 5%, 10%, 15%, and 20%. The marshal test, as well as the ductility test, are to be performed when considering the following bitumen percentages: 4%, 4.5%, 5%, 5.5%, and 6%. The optimum asphalt and rubber contents are investigated by applying several trial mixes containing different bitumen and rubber percentages: 95% and 5% rubber, 90% and 10% rubber, 85% and 15% rubber, and 80% and 20%, respectively. Based on the lab test results, relevant entities and stakeholders are recommended to use such materials in the paving of asphalt roads. From an optimistic point of view, the use of such materials is expected to minimize the unit cost of pavement (square meter) as well as the environmental impacts (a friendly solution to tire waste problems). The results indicate that 10% and 15% of rubber satisfy the standards and specifications.
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