When my parking lot was first paved it was jet black, but two years later it is turning gray. What is happening?
The asphalt cement (“a/c”), which is the black liquid that binds the aggregate (stone) together to form blacktop, has no resistance to the oxidizing effects of the infrared radiation produced by the sun. Infrared radiation attacks your driveway even on a cloudy day and the asphalt cement is being evaporated away, showing the lighter gray color of the stones that make up the blacktop. Our coal tar sealer is impervious to oxidation.
