What are the different types of “whitetopping” techniques used for concrete overlay in road construction projects?
Whitetopping is a concrete overlay technique used to extend the life of asphalt pavement roadways.
With whitetopping, a layer of concrete is placed on top of the existing asphalt pavement. The purpose of whitetopping is to rehabilitate the existing roadway in order to extend its usable life. Whitetopping might utilize bonded or unbonded concrete overlay techniques. With unbonded whitetopping, a thicker slab of concrete is poured on top of the existing asphalt pavement without bonding the concrete to the asphalt. With bonded white topping, typically, a Contractor prepares the asphalt to bond with the concrete laid on top of it by texturing or milling the asphalt surface before pouring the concrete overlay. When bonded whitetopping is utilized, it may consist of either “thin” (4-6 inches) or “ultrathin” (2-4 inches) concrete overlay. Each of these variations has its applications for which it is best suited, and design specifications address the size of the concrete panel and the specific joint placement to account for the thickness of the concrete overlay.