Diamond grinding to be used on Loop 101 Price Freeway pavement

Widening project part of analysis of ways to limit tire noise

PHOENIX – A stretch of the Loop 101 Price Freeway in the southeast Valley will undergo a specialized concrete smoothing process in the coming months as part of a regional analysis of Phoenix-area freeway pavements.

The Arizona Department of Transportation is widening Loop 101 in this area as part of a $60 million improvement project that started in May 2019 and is scheduled for completion this fall.

The Maricopa Association of Governments (MAG), the Phoenix region’s freeway planning agency, supports ADOT’s upcoming work to diamond grind the concrete surface along the Price Freeway between Baseline Road and Loop 202 (Santan Freeway).

The diamond grinding, which is expected to start Friday, May 8, involves the use of machines with diamond-tipped blades on rotating drums to smooth a freeway’s existing concrete pavement while also creating grooves designed to limit vehicle tire noise.

MAG and ADOT have partnered on an analysis of pavement treatments used to limit noise generated by tires as vehicles travel on Valley freeways. Many of the region’s urban freeways were resurfaced more than 10 years ago with a 1-inch top layer of noise-reducing rubberized asphalt.

At a time when the service life of numerous rubberized asphalt overlays has been extended beyond an anticipated 10 years, ADOT and MAG have faced decisions about long-term costs associated with pavement wear over time. That includes whether to resurface a freeway with rubberized asphalt or use an alternative surface treatment such as diamond grinding a freeway’s concrete pavement.

ADOT recently gained experience with replacing older rubberized asphalt overlays by diamond grinding three areas along Loop 202 (Santan Freeway) in Chandler. Those locations are examples where the worn asphalt pavement was in place well beyond its planned service life, resulting in rough surface conditions. Diamond grinding provided a much improved, smooth concrete driving surface.

Older rubberized asphalt was removed from the Price Freeway south of US 60 last year as part of ADOT’s widening project. MAG supports the expanded use of diamond grinding within the project’s boundaries as consideration is given to additional research about different pavement surfaces, long-term costs and efforts to limit noise along regional freeways.