Mix it Up

The Alaska Department of Transportation & Public Facilities is on the front line when it comes to promoting new technologies that give them continuous, full coverage asphalt pavement density testing for road paving projects. Continuous testing uses multiple inputs to look for failure zones and has a high probability of detecting defects before they lead […]

In the January 2018 issue, Courtney Jones and Mike Heitzman from the National Center for Asphalt Technology (NCAT) at Auburn, shared “Michigan Tests Friction Aggregates” from their contribution to the fall 2017 NCAT Newsletter. This excellent article can be reviewed on www.TheAsphaltPro.com. The authors shared results of evaluating 11 aggregates for high friction surface treatments […]

We all know that in our industry, what works for one climate may not work for another, and low gyration mix designs are no exception. “We have a similar mix design at the National Center for Asphalt Technology (NCAT) test track in Alabama,” said Robert Semones, branch manager of the Kentucky Department of Transportation (KYTC) […]

Editor’s Note: Read the February issue for findings from the Florida Department of Transportation’s experience with HFSTs over time. High friction surface treatments (HFST) provide enhanced pavement friction in critical safety locations such as horizontal curves and bridge decks. HFSTs are a thin layer of durable, high friction aggregate bonded to an existing pavement surface […]

How cubical do the aggregate particles used in Stone Matrix Asphalt (SMA) need to be to achieve acceptable performance? European specifications require SMA aggregates to have no more than 30 percent Los Angeles (L.A.) abrasion loss (AASHTO T96) and no more than 20 percent flat and elongated (F&E) particles when measured at a 3:1 ratio […]

In 2016, the Russellville School District in Arkansas awarded a large contract to reroof its middle school facility. As part of the project, the general contractor took 120 tons of shingles off the roof in late December, and wisely partnered with a local roadbuilding contractor that kept the material for future use. “There was some […]

In September 2015, the Federal Highway Administration (FHWA) Expert Task Group on Mixtures and Construction formed a Balanced Mix Design Task Force. This group defined balanced mix design (BMD) as “asphalt mix design using performance tests on appropriately conditioned specimens that address multiple modes of distress taking into consideration mix aging, traffic, climate and location […]

In the past, technology hadn’t paved the way for the successful use of ground tire rubber (GTR) in asphalt mix designs the way it has today. Now we have the means to grind tires “finer.” We can use advanced mixing chemicals that facilitate the use of wet process and dry crumb rubber modified asphalt cements […]