Q&A

This question comes from Chris Vogt, Public Works Director and City Engineer, La Quinta, CA.

Does Asphalt-Rubber reduce pavement noise levels?

Answer:
Numerous noise level studies in the U.S. and abroad prove use of Asphalt Rubber as the binder in hot mixes reduce traffic noise levels dramatically.

This phenomenon was first noted in Brussels, Belgium in 1981 in an A-R hot mix called "Drainasphalt' " Since then numerous studies have been conducted in 3 continents on A-R hot mix pavements where the results have been documented in published technical papers available from the RPA library. The 1981 Belgium investigation was conducted on the Brussels loop by Professor E. Nakkel, President of a Technical Committee on "Asphaltstrasen" , Bonn, Germany. Professor E. Nakkel writes of the high cost of noise reduction using sound barriers and the results of his study which reveals a reduction of 8-10 dBs through the use of A-R Hot Mix. This means a significant cost savings by eliminating the need for sound barriers. in the U.S., both the City of Phoenix and the AZ DOT have conducted studies. In 1990, Phoenix, using a I" A-R GG overlay found a noise reduction of 10dB or approximately 88%. Earlier, in 1989, ADOT using an open graded A-R hot mix over PCCP on the 1-19 near Tucson, found a noise reduction of 6.7 dB from the existing pavement to the A-R 'Open graded. This relates to a 78% reduction. Both studies were conducted by Western Technologies, Inc of Phoenix, AZ. The results of these and other tests have led to routine usage of the Asphalt-Rubber GG and OG mixes by ADOT to reduce noise levels in urban areas, many placed by my company, FNF Construction, which utilized 1.3 million tires in its 1996 paving season.

For copies of noise study reports, call RPA (480)-517-9944.