Hot Mix Asphalt Technology - January/February 2008 - (Page 47)

Big Creek Teams with TxDOT continued The bulk of the paving activity took place at night. The crews from Big Creek laid 28,000 tons of PFC and 22,000 tons of CAM, a specialty mix developed by TxDOT. starts and stops, managing to complete the rehabilitation work on budget and on time during one of the wettest summers in the recent history of central Texas. “Using hot-mix asphalt enabled us to work around a changing schedule,” said Wade Miller, assistant director at Big Creek. “Still it was frustrating for our crews to have to wait out the repeated rains.” The Big Creek crews put down 28,000 tons of porous friction course (PFC) asphalt and an additional 22,000 tons of CAM, a specialty mix. The CAM (crack attenuated mix) was specified by TxDOT in Waco after learning that the mix had received good reviews in the Houston area where it has been used on both highways and surface streets. “The mix was originally developed to be laid over concrete pavement and resist the cracking from migrating to the surface of the road,” said Duane Schwarz, director of TxDOT construction in the Waco district. “For the TempleBelton project, it would be laid over an old asphalt surface. We wanted to have the CAM laid down on the milled area and be an impermeable surface, then have the PFC laid on top for safety reasons because of its effectiveness in reducing splash and spray.” The CAM as specified by TxDOT had 65 percent granite screenings, 34 percent fine crushed gravel aggregate, and 1 percent hydrated lime. The asphalt content was 7.5 percent by weight of the aggregate. The PG binder used was 76-22 and contained recycled rubber. Specifiers at TxDOT wanted to insure that the layer was impermeable, since the PFC layer on top has interconnected voids, allowing the water to quickly drain through the pavement and away from the surface where the water would otherwise be kicked up as spray from passing vehicles. The lab density for the PFC was 78 to 82 percent. In other parts of the country PFC is known as opengraded friction course (OGFC). RB500 International acclaim of the RMI RB500 revolutionizes airport runway, taxiway, ramp and highway rubblization. 339546_Resonant.indd 1 Rubblizing We wrote the book on it. Contact us. Contact us for a FREE Video! www.resonantmachines.com Videos, specifications and current projects available online. 918-749-2209 2835 E. Skelly Dr., Suite 838 Tulsa, Oklahoma 74105 Hot Mix Asphalt Technology – JANUARY/FEBRUARY 2008 • 47 PM 8/28/07 8:30:33 http://www.resonantmachines.com

Table of Contents Feed for the Digital Edition of Hot Mix Asphalt Technology - January/February 2008

Hot Mix Asphalt Technology - January/February 2008 Contents Chairman's Commentary President's Perspective A Conversation with the New NCAT Director NCAT Test Track: Real-Time Testing for Real-World Results Warm Mix: The Lights are Green Illinois Tollway Tests RAP in Fast Forwarded Research Big Creek Teams with TxDOT to Pave Using Innovative Asphalt Mix Diamond Achievement Commendation Issues a Call for Quality Calendar of Events CONEXPO-CON/AGG Product Review Index of Advertisers Advertisers.com

Hot Mix Asphalt Technology - January/February 2008

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