Diamond Grinding

Smoothing Price Freeway's concrete surface part of regional pavement study

Smoothing Price Freeway's concrete surface part of regional pavement study

Smoothing Price Freeway's concrete surface part of regional pavement study

By David Rookhuyzen / ADOT Communications

May 22, 2020

Those of you who use the section of Loop 101 south of US 60 (Superstition Freeway) in the East Valley have had to practice patience over the past year while the Price Freeway has been undergoing a widening project.

In the coming months, drivers will not only have new lanes between Baseline Road and Loop 202 (Santan Freeway) but a smooth concrete pavement surface created by a specialized process called diamond grinding.

ADOT's use of diamond grinding, which involves the use of specialized machines with diamond-tipped blades to smooth a freeway’s concrete pavement, is part of an analysis of pavement treatments supported by the Maricopa Association of Governments, which serves as the Valley’s regional freeway planning agency.

While smoothing the pavement, diamond grinding also creates grooves designed to limit vehicle tire noise.

It's the same process crews used earlier this year on the Loop 202 Santan in the Chandler area to improve stretches where rubberized asphalt surface pavement that was well beyond its planned surface life resulted rough surface conditions. Diamond grinding in that area had the desired effect of providing a smooth drive. You can see what the process looks like in action in this video from the work on the Loop 202 to the right.

More than a decade ago, many Phoenix freeways were resurfaced with an inch of smooth rubberized asphalt. Many sections of those rubberized asphalt overlays have been in place longer than a planned service life of 10 years.With that in mind, ADOT and MAG are evaluating decisions over the long-term costs related to pavement wear and replacement. Part of that is considering whether to resurface using rubberized asphalt or using alternative techniques, such as diamond grinding.

The two agencies will continue to study and consider surface pavement alternatives with cost effectiveness, noise limiting benefits and a smooth ride in mind.

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ADOT testing concrete pavement treatment along Loop 202

ADOT testing concrete pavement treatment along Loop 202

ADOT testing concrete pavement treatment along Loop 202

June 19, 2019

PHOENIX – Arizona Department of Transportation engineers are exploring another option for smoothing out the ride along Phoenix-area freeways where the asphalt pavement showed its age and was wearing down, especially after last winter’s heavier wet weather.

It’s called diamond grinding – where a specialized grinding machine uses diamond-tipped saw blades to both smooth and add small grooves in a freeway’s concrete-base pavement. Concrete industry contractors developed diamond grinding to improve ride quality, limit noise and provide increased surface friction to enhance stopping on the pavement.

The Arizona Department of Transportation will evaluate a section of eastbound Loop 202 (Santan Freeway) in Chandler where diamond grinding was done as part of a recent pavement repair and preservation project.

The diamond grind test section is along the eastbound Loop 202’s right two lanes near Dobson Road. Crews last month removed a 1-inch layer of rubberized asphalt that was worn out by time, traffic and Mother Nature.

“This is another tool in our pavement-improvement tool box,” said Randy Everett, senior administrator of ADOT’s Central Construction and Maintenance District serving the Phoenix area. “This is an opportunity to explore options and see how the diamond grind performs in an area where the rubberized asphalt finally wore down well after its expected lifespan of 10 years.”

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The eastbound Loop 202 on-ramp at Alma School Road also was treated with the diamond grind process in May.

Much of the Santan Freeway’s rubberized asphalt surface between the US 60 interchange in Mesa and Loop 101 in Chandler also was given an asphalt-based sealant treatment recently. That fog seal treatment, which has been used on several other Valley freeways, is designed to extend the life of the existing asphalt pavement.

ADOT maintenance crews used weekend closures along the Santan Freeway last month to fix potholes or make repairs to other sections of worn pavement.

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