Experimental Study of Acoustical Properties of Recycled Rubber Panels

This paper is focused on the characterization of multilayer acoustic panels made from recycled rubber waste produced by the Zebra factory in Bulgaria. The acoustical characteristics of rubber samples as well as three-layer panels were investigated to determine their applications as sound barriers or resilient flooring. The experiments to determine the sound absorption and sound reflection coefficients were carried out in laboratory conditions using the standing wave method in the frequency range from 100 to 2000 Hz. The potential of recycled materials to reduce airborne and impact noise was investigated and discussed. The sound insulation coefficients of recycled rubber panels were determined by the "two-chamber" method in the frequency range from 100 to 4000 Hz. For this purpose, small acoustic chambers were constructed and tested. The dynamic properties (dynamic stiffness and damping ratio) of the experimental materials were also investigated by an impact test. The obtained results have been discussed and analyzed with a view to evaluating the possibilities of application as acoustic barriers and flooring.