Asphalt surface treatments refer to the reconditioning of the wearing (surface) course of older existing asphalt pavements. The term may also be applied to the final phases of new asphalt pavement construction. (Article 32.12.16 discusses Asphalt Paving).
Surface treatments provide enhanced waterproofing of the pavement, prevent the raveling (detachment and loss) of the fine aggregates (i.e. sand) from within the surface course of the pavement, smooth out existing surface imperfections, and provide improved skid resistance for vehicle traffic. Asphalt surface treatments are nominally less than an inch thick.