Why does up to date asphalt turn grey?
Answers: Asphalt is a combination of sand, stones and liquid asphalt cement. Eventually sun, salt and water exposure will exact the cement to evaporate. This will cause the asphalt to turn gray in color. The gray color indicates pavement that has too much sand and stone compared to the amount of asphalt cement.
thats the top of the asphalt oxidizing. alike thing happens to hamburger, actually.
