How is bitumen emulsion layered in a typical road pavement cross section?

In a typical pavement, bitumen emulsion is used as a tack coat between asphalt lifts to ensure bonding, and sometimes as a prime coat on granular bases or as a binder in surface dressing or slurry seal layers. Placement depends on design: tack coats are thin and uniform, while surface dressing uses emulsion plus aggregate to create a wearing surface. The emulsion must break and cure before the next layer to avoid slippage or stripping.