Impact of the Use of Crumb Rubber Modified Binder on Tire/Road Noise Generation

The recycling of waste material produced by human activity is one of the challenges of our generation. One of the most serious environmental problems of the recent years is mass production of tire and the di􏰟culty of disposing of them. The material and energetic valorization of the wasted tires is possible through the extension of 􏰔green roads􏰕. The incorporation of crumb rubber from wasted tires in bi- tuminous binders allows the design of new asphalt pavements with a higher viscosity. A preliminary study to determine the impact of the use of crumb rubber modi􏰝ed bituminous binder in the sound generation level for a thin layer type BBTM11A, has been carried out by the LA2IC. These results are compared with sound level from a BBTM11A with a conventional binder. This work presents the acoustical characterization performed on the regional road CM-3102 in Ciudad Real (Castilla- La Mancha), based on the close proximity methodology (Tiresonic Mk4-LA2IC ). In addition, mea- surements of super􏰝cial macrotexture pro􏰝le have been realized with the LaserDynamicPG-LA2IC to study the relationship with close proximity road noise. Furthermore, sound absorption measurements of BBTM11A compacted samples have been analyzed to understand the mechanisms involved in the sound generation. The results show that addition of crumb rubber by the wet process leads, in this case (20% crumb rubber content), to a decrease in the sound level emitted by the interaction between tire and road surface, at low frequency by mu􏰠ing the vibrations and by sounf absorption at high frequency.