STUDY OF CRUMB TIRE RUBBER IN ASPHALT CONCRETE MIXTURES

The aim of this work is to characterize the structural and mechanical behavior of asphalt mixtures when some recycled rubber is added. The basic asphalt mixture is the one commonly used in asphalt pavement; the recycled rubber comes from used tires. The research methodology used made it possible to optimize the rubber addition so the structural behavior of resulting asphalt mixtures is improved when compared to the basic mixture without rubber. The study investigates the effects of the addition of crumb tire rubber in asphalt concrete mixtures. The process of incorporation of rubber is similar to the aggregate-rubber process (dry), but seeking the asphalt-rubber process (wet). The study optimizes the asphalt binder and rubber contents with the aid of the Marshall method. The mixture performance is evaluated with the indirect tensile strength, resilient modulus and fatigue tests on Marshall samples. Pavement design simulation with the experimental mixture shows advantages compared to the conventional mixture.