When design-build meets warm mix

Aug 07, 2017

Interstate 95 (I-95) is the main interstate highway on the east coast of the U.S., running for almost 2,000 miles. 382 miles along I-95 pass through the state of Florida. Its southernmost portion transports the traffic along Florida’s Atlantic coast. In 2014, international general contractor Archer Western Construction began an 11-mile design-build project on I-95 that included widening and realigning the road. Archer Western is one of the largest mass transit and bridge contractors in the U.S. and is ranked by Engineering News Record as the 12th largest mass transit and rail contractor in the country.

Archer Western designed the project to include an open-graded bonded friction course (Florida’s FC-5) to shed water along the highway, and specified a PG 82-22 binder for its rut-resistant qualities. PG 82-22 mixes are often used on bus pads in Florida in order to mitigate shoving and deformation amidst heavy loads in the sunny, hot climate. PG 82-22 mixes are also one of the most sensitive designs in terms of temperature, so the window of opportunity to properly seat the stone is very limited. When Evotherm® is added to the mix, it provides additional workability time to address issues as they arise, such as the removal of any deleterious materials on the mat.

P&S Paving of Daytona Beach was the subcontractor on a 30,000-ton phase of the project and chose Evotherm to complete the job.

“The pay factors on the project were gradation, texture, spread rate and liquid binder content,” explained Tim Carter, director of quality control at P&S. “With spread rate restrictions in particular, there is a high probability of texture issues because you’re laying the asphalt so thinly. So it’s important that the rocks coat well and stay put, quickly. This is where Evotherm really helps. We just don’t see any tenderness, pushing or shoving of the asphalt.” The spread rate was specified at 83 pounds and the liquid binder content was 6 percent.

Tim continued: “Blending Evotherm at the terminal prior to shipment also makes it easy to use and ensures that every drop of liquid receives the proper dosage for maximum consistency. We get paid for consistency so I do everything I can to get paid the most.”

How is Evotherm positively impacting the reputation of P&S?

“From the time the stone hits our yard to the time it receives its last roller pass, everything we do is geared towards providing our client the most consistent and top quality asphalt mixture possible,” said Carter. “Evotherm has become a major player in that effort. With our reputation at stake and the fact that the I-95 project is extremely high profile, we couldn’t take any chances with quality. That’s why we’ve chosen to use the best materials available, like Ingevity’s warm mix additive. We’re proud of an outstanding finished product.”