If you were to fly into the Ft Lauderdale, FL, airport, or KFLL, you would see the following information about their longest runways:
RUNWAY 9L/27R Dimensions: 9000 X 150 ft. Runway Edge Lights High Intensity Surface: Asphalt / Grooved
So the runway is made out of asphalt, but it's grooved? What does that mean?
Runway pavement surface is prepared and maintained to maximise friction for wheel braking. To minimize hydroplaning following heavy rain, the pavement surface is usually grooved so that the surface water film flows into the grooves and the peaks between grooves will still be in contact with the aircraft tires. To maintain the macrotexturing built into the runway by the grooves, maintenance crews engage in Airfield rubber removal in order to meet required FAA friction levels. From Wikipedia.Well, I have to admit I saw the hyperlink on Airfield rubber removal and didn't have a clue. I have never even thought about having to clean off those black "skid" marks on the runway (left because the tires aren't spinning when an airplane touches down). I learned something new, too. Which, in all honesty, is a lot of the reason I do this blog - I am still learning. The picture of the runway (below) is from my home base, Cleveland Hopkins International Airport.
Airfield rubber removal, also known as runway rubber removal, is the use of high pressure water, abrasives, chemicals and/or other mechanical means to remove the rubber that builds up on airport landing strips. The Federal Aviation Administration (FAA) specifies friction levels for safe operation of planes and measures friction coefficients for the evaluation of appropriate friction levels. Individual airports incorporate rubber removal into their maintenance schedules based on the number of take offs and landings that each airport experiences. Wikipedia.