Acoustic field evaluation of asphalt mixtures with crumb rubber

The aim of this study is to characterize the acoustical behavior of bituminous mixtures fabricated with recycled rubber crumb. Acoustic field measurements of the tire/pavement interaction in close proximity to the contact patch were carried out with a trailer with a protective chamber (TiresonicMk4-LA2IC). The survey was conducted on a test track with several experimental sections paved with a gap-graded mixture. Different methods of incorporating crumb rubber in the mixture were used: (i) into binder and (ii) with the aggregate materials. Close proximity sound levels are assigned to the gap-graded mixtures containing rubber and compared to that of a reference mixture without rubber. It is shown that asphalt mixtures fabricated with the addition of crumb rubber to the aggregate material (dry process) managed to reduce the noise from the tire/pavement interaction up to 2 dB(A).