If you had to take a guess, what would you think the life expectancy is for the average airport runway?

Chances are, most people would put that number somewhere between 50 or even 75 years but the reality is that until fairly recently, most runways and taxiways were designed for a shelf life of just two decades.

“Generally, runways and taxiways are designed for a twenty year life,” says Adil Godiwalla with the Design & Construction Division of the Houston Airport System. “After that, most airports demolish them in 20 years and start from scratch again.”

But a perfect example of new technology and design methods combining to increase the lifespan of a runway can be found at George Bush Intercontinental Airport (IAH).

The runway is 9/27, a ten-thousand foot strip that essentially runs parallel to the terminal facilities between Will Clayton Parkway and JFK Blvd.

The advancement was actually initiated more than twenty years ago, back in 1987. That’s when design teams with the Houston Airport System decided to use something called a Lime Cement Fly Ash Stabilized Base.

Simply put, it allowed Runway 9/27 to strengthen its base level by almost 400%, give future design teams the option of laying new concrete on top of the base, rather than starting over with an entirely new runway.

And that’s exactly what’s currently happening with Runway 9/27, as construction crews finish work on a 14 inch concrete overlay on the runway itself, as well as seven different taxiways.

Work crews are also using the closure time to update much of the electrical features associated with the runway. New airfield light cans, conduits and light fixtures are all part of the work that’s ongoing at this time.

The runway was first closed on October 1, 2008. The work is expected to be completed a short four months later, around January 31, 2009. At that point, the Federal Aviation Administration will begin performing “flight checks,” a process that will likely take seven to fourteen days to complete.