The effect of consolidation on the acoustic properties of loose rubber granulates

Acoustical performance of porous absorber made from recycled rubber and polyurethane resin

“…This expression, used for consolidated elastic rubber granulates, showed previously by Horoshenkov and Swift (2000), show an empirical dependence between the binder concentration and the flow resistivity:…”

“…Another study conducted by Jimenez-Espadafor et al (2011) suggested that the waste tyre textile (fluff) could be mixed in the same proportion with hot melt adhesive to produce a real acoustic ceiling tile with a very high absorption coefficient. Horoshenkov and Swift (2000) showed that the application of the binder has considerable effect on the acoustical properties of the rubber granular mix. In the case of improvements on the traffic noise, Paje et al (2010) showed that the acoustical performance of pavement surfaces made from bituminous mixtures, fabricated with recycled tyres (incorporating crumb rubber as aggregate), managed to reduce the noise reduction up to 2 dB(A) and Han et al (2008) verified that crumb rubber blends present a potentially viable alternative to current concrete highway noise barriers.…”

Thermoplastic composite beam structures from mixtures of recycled HDPE and rubber crumb for acoustic energy absorption

“…These studies have shown that improvements in acoustic damping capability can be obtained over a wide frequency range, owing to the high porosity caused by the dispersed particles 8,9,11 . The effects of adhesives and polymeric binders have also been studied 9,13,[16][17] while Zhou et al 2 have developed composite sound absorbing perforated panels, combining double-layer structures of recycled rubber particles with opencell polyurethane foam. More recently, the sound insulation properties of wood/recycled tyre rubber composite panels have been investigated and it has been shown that an increase in recycled rubber crumb produced improvements in soundproofing properties 3 .…”

Numerical Modelling of the Sound Fields in Urban Streets With Diffusely Reflecting Boundaries

“…With an absorption coefficient of 0Á9 the extra attenuation is 6-7 dB along the length, which is significant and also approximately indicates the maximum effectiveness of boundary absorption on noise reduction. Recently, there have been considerable works on outdoor sound absorbers [32,[36][37], mainly for noise barriers, but they are also useful for urban streets. Moreover, open windows and gaps between buildings can be regarded as sound energy sinks.…”