Better Roads

March 2014

Better Roads Digital Magazine

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HighwayContractor 20 March 2014 Better Roads The best plan for a stronger foundation... Encourage Excellence! Visit to see our full line of awards and recognition products or call for a quote 1.800.633.2021. CUSTOM AWARDS FOR: ;INM\a 1VVW^I\QWV AMIZ[WN;MZ^QKM 4MILMZ[PQX )VL[WU]KPUWZM Let us help you recognize your workforce! rubber – minus 40 mesh – into a mixing drum or into a mix- ing pugmill located at the discharge end of the dryer drum. "Now we have the DOT behind us with specifi cations for it, so they wanted more control over the process," Marshall says. "Our machines have a weigh depletion system that can mea- sure the dry rubber." Marshall uses CRM binder to bump up the grade of base virgin asphalt to a typical PG 76-22. That binder is used on high-traffi c state routes and interstates. Base liquid, which for Reeves is typically a PG 67-22, is taken and then enough rub- ber is added to bring it up to meet the requirements of a PG 76-22, Marshall says. With the latest binder, 8 percent rubber is being added to the total binder to meet DOT specs, he says. The material normally comes in 2,000-pound Super Sacks. "If the state lets a project that requires polymerized asphalt, you can either use the PG 76-22 SBS or in lieu of that, you can use crumb rubber," Marshall says. "The spec reads that it has to meet the same specs as the SBS [styrene butadiene styrene] polymer." Marshall says he and Reeves offi cers like crumb rub- ber because its price is stable, unlike that of polymer. Major projects often take a couple of years from the bid date to start of construction. So the volatile price of polymer makes it dif- fi cult to bid an asphalt paving project. If a contractor bids for a polymer project at the current price, it could easily jump by construction time. If the contractor bids an escalated price, the risk is that someone else would underbid that price. Reeves Construction Co. has just fi nished a project on I-75 that has 2 inches of SMA with crumb rubber and a friction course in downtown Macon, Ga., coming north through Ma- con toward Atlanta. "I think we used something like 40,000 tons of rubberized asphalt out there," Marshall says. "We use it on a lot of state routes. We have a job down in Tifton that has nearly 90,000 tons on U.S. 319 that will be laid this year. And we have a 50,000-ton job down in Albany that will be starting as soon as the weather breaks." On Interstate 10 In California, Granite Construction Co. recently performed a "mill-and-fi ll" project by milling 1/10 of a foot from a

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