Equipment World

August 2015

Equipment World Digital Magazine

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EquipmentWorld.com | August 2015 61 D windling budgets and the uncertainty about the Highway Trust Fund have caused departments of trans- portation and municipalities to take longer looks at pavement preserva- tion techniques. In light of this, more transporta- tion entities are looking at thin overlays – commonly called thin- lays – as a way to rehabilitate roads rather than replace them. Asphalt thinlays, which range from 3/4-inch to 1-inch thick, are created with smaller nominal maximum aggregate sizes than typical asphalt pavement and are supplemented with more asphalt binder mix that is formulated to be softer. That helps make the mix more durable and resistant to cracking – ideal attributes for a preservation product. Chuck Fuller, president of J.D. Ramming Paving in Austin, Texas, has been working with thinlays for more than eight years. He's also involved with the National Asphalt Pavement Association in their pavement preservation educational efforts, and has spoken about his experience with thinlays at an education session at the World of Asphalt show. While thinlay use is growing, Fuller says, there also is some trepidation because of some cases of misuse, cases that lead to mixed results and even failures. "Thinlays are a pavement preser- vation tool," he says. "That needs to be stressed more than anything. A thinlay is not a dense-graded mate- rial. It does have structural value, but it's not to be used solely for a typical structural valued roadway." Fuller's company learned some valuable lessons on a project that used thinlay instead of a standard- thickness mat to widen a roadway to create turning lanes. The pave- ment quickly failed. The underlying structure of the roadbed, he explains, has to be sound for a thinlay to perform properly. For example, if there is block cracking, then a contractor has to crack seal the roadway or apply an underseal membrane on the material. But because thinlays have had a high success rate in preserv- ing roadways – and generally are thought to extend the life of a pavement for at least seven years – there is a rush to use this method outside of its intended application, Fuller says. "It's an ongoing battle for proper highway contractor | by Chris Hill | ChrisHill@randallreilly.com AS A PAVEMENT PRESERVATION TOOL, THIS METHOD CAN EXTEND THE LIFE OF ROADWAYS WHILE ADDING SLIGHT STRUCTURAL INTEGRITY THINLAYS

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