The North Texas Tollway is creating its own recycled material and using it on its own Sam Rayburn Tollway project.

“The green effort equates to time and money savings while furthering the NTTA’s sustainability efforts,” NTTA’s spokeswoman Susan Slupecki tells Texas Construction.

Houston-based W.W. Webber LLC set up three concrete recycling machines to crush old concrete and repurpose it into different-sized materials. The material is used in pipe bedding or various fill material, Slupecki says.

A “stomper” crunches the old concrete and underlying asphalt in 18-ft-wide sections.

Hydraulic excavators then rake out the concrete and remove the reinforcing steel. The underlying asphalt is removed and the concrete is recycled on site. The asphalt goes to a plant, where a percentage of the original material is put back into new asphalt sub-grade on the interchange project. The remaining recycled asphalt is available for use on other projects.

Meanwhile, the steel goes to a mill, and is recycled for use in projects in North Texas.

To date, Webber and NTTA have recycled approximately 27,000 cu yds of concrete. Some 1.9 million lbs of steel have been recycled.

NTTA’s sustainability efforts also include uncoated concrete; landscaping with native plants; and storm-water recycling.

“The on-site recycling supplies reprocessed materials back into our own project,” Slupecki says. “We help the environment, and cut costs and time by using fewer trucks.”

The project involves building the four-level SRT/U.S. 75 interchange and rebuilding the main lanes and frontage roads.

The NTTA expects to open the new interchange to traffic in January 2011.