Evaluation of sustainable asphalt mixtures with crumb rubber using cracking index

Fatigue in asphalt mixtures is one of the main failures that occur in flexible pavements. This problem is generated by the successive passage of vehicles and manifests itself on the rolling surface as cracks of short length. These fissures, when they reach a certain size, interconnect with each other to form a lattice that is commonly referred to as crocodile skin. This problem of pavements is not generated by reaching the ultimate strength of the material, but by exceeding the permissible tensile stress under repeated loads in the lower fiber of the asphalt layer. On the other hand, the inclusion of waste material is becoming increasingly necessary due to the large generation of waste. One of them is Crumb Tire Rubber (CTR) which is a suitable waste for use in the asphalt paving industry. The shredding of the tires to a millimeter size allows them to be used in this way. This condition ensures that the CTR is incorporated into the asphalt to form a homogeneous material that does not separate in its phases. The present work proposes the characterization of asphalts with 15 and 18% of CTR above the weight of asphalt in conjunction with the base asphalt, employing rheological analyses with short and long term aging. Subsequently, a dense asphalt mixture is designed with the previously mentioned asphalts to perform the Indirect Traction test and evaluate the results with cracking indices to estimate the fatigue in pavements. Finally, correlations are proposed between the parameters of the asphalt and the asphalt mixtures obtained, which show an acceptable relationship. Superior performance of asphalt mixtures with CTR can be seen through the cracking indices compared to the standard sample.