What are the different grades of asphalt?

Answer 1

Well, the traditional superpave grade is on the order of PG ##-##, this means, for example. A grade of asphalt, say, PG 70-40 is a mix where the 70 stands for the asphalt temp max over the next seven days after layment of 70 degrees and the min experienced temp the grade should encounter is 40 degrees. This means, that this PG 70-40, is where the 70 degrees is the layment temp max and the min temp to ever encounter is 40 degrees. This mix uses high grade crude oil and aggregate. Other grades use typical crude, modifiers and aggregate depending on the roadway. If your question pertains to what aggregate size, type of modifier or crude selection, this is something that you would need to engineer. Far to complicated to detail in this section. Thanks,