Phoenix — A former Space Shuttle runway is getting a "green" makeover. Arizona Public Service Co. (APS) is providing 12,000 tons of fly ash to repair a deteriorating concrete runway that has seen some of the world's most famous pilots and astronauts.

Edwards Air Force Base, located 110 miles northeast of Los Angeles, is home to the Air Force Flight Test Center and has been the site of numerous Space Shuttle landings. However, after more than 50 years of record-breaking use, the runway is starting to deteriorate. A new 15,000-foot main runway is being built with concrete made with fly ash sold from Four Corners to Salt River Materials Group, APS' longstanding fly ash marketing partner. Construction began on the runway in January and is expected to be completed by the end of the year.

Fly ash is a by-product of burning coal. When used in concrete manufacturing, fly ash is truly a "green" building material because it replaces a portion of the portland cement, and the resulting emissions associated with its production. Fly ash has the consistency of fine powder. Due to the shape, size and chemical composition, it imparts a number of benefits to concrete such as reduced water demand, improved durability and increased strength.

Salt River Materials Group (SRMG) buys, processes, and markets approximately 600,000 tons of fly ash per year from APS. Not just used in concrete, fly ash is also used in other applications like soil and base stabilization. For example, the stretch of U.S. Highway 550 between Bloomfield and Albuquerque, N.M., also was constructed using fly ash.