Infrastructure - Airports

By Marcus Kirkwood

As we continue to dig into the facts about infrastructure, today we hop out of a car and into an airplane. Think of it like a little mental vacation, since getting on a real airplane in 2020 is more of a delusion than a reality. Do you ever wonder how in the world a giant aluminum can with wings can take off and fly across the world with hundreds of people on board? Me too. But you won’t find the answer to that question here. All I can say is: physics. That’s not our area of expertise.

Given our affinity for construction, I tend to wonder how that same airplane, loaded with people, bags and fuel can land on a runway and not blow either surface to pieces. Think about how many airplanes hit that surface every day! At JFK in New York, 800 planes come and go on a daily basis. Those planes average anywhere between 175,000 and 775,000 pounds at take off. 3/4 of a million pounds!!! What?? Computing that compression weight on a landing surface AND factoring downward speed…..

What I can tell you is that people who are way smarter than me have figured it out. And it works every time. Here’s the recipe:

The average major US airport that sees consistent commercial traffic has runways made of concrete that range from 18-24” in thickness. The average sidewalk is 3-4” thickness. That doesn’t take into account the support inside those concrete panels that keeps them in place and holds their tensile strength. As we’ve discussed in some of our other blogs on concrete and rebar support, concrete has very high compressive strength and very low tensile strength. In order to improve that strength, runway panels have multiple ‘mats’ or layers of rebar and/or mesh to provide concrete with a skeleton to keep it strong.

The reason we refer to runways as panels is they often become just that. It is not uncommon for the average commercial airport to shut down a runway for an extended period of time during their busy season to replace chipped or cracked panels. Each panel is cut or broken out and replaced with new steel and concrete. Apparently giant airplanes landing on them every day does cause them to blow to pieces. It just takes time…

At Outpost, we love runway rehab projects and carry everything you need on site from shovels, to safety equipment to erosion control, epoxies, spall repair products and tools. Don’t hesitate to put our concrete chemicals to the test either. We’d love to hear from you on our site or see you at our front door!

Happy flying…someday…