The Problem Texas has some of the best roads in the nation. However, some materials used in constructing and maintaining these roads can pollute the air. An example includes cutback asphalt prime coats used to seal a prepared base and ensure the surface of a road adheres to its base.
Engineers typically place asphalt pavements in two courses.
First, they place and compact an aggregate base course, and then they place an asphalt surface. The compacted base course is sprayed with a prime coat before the surface is placed. The prime coat helps the surface bind to the base because it precoats the base with the asphalt used in the surface course. Since the asphalt prime coat needs to be applied in a liquid state, it is blended with gasoline, kerosene or diesel. This extreme pollution has limited cutback asphalt usage to only 8 percent of all asphalt used in Texas.