Thin overlays may be used for pavement preservation, maintenance or rehabilitation depending upon the extent of the work and the thickness of overlay. When used for pavement preservation, thin overlays or thinlays are applied to the pavement surface in order to extend pavement life while improving ride quality and skid resistance. Overlays less than two inches thick are employed as maintenance treatments to restore ride quality and address surface defects.
Thin asphalt overlays for pavement preservation and maintenance provide several benefits as compared to other preservation and maintenance alternatives (FHWA, 1999). These benefits are identified below.
Long service life
Low life cycle costs
Ability to withstand heavy traffic
Quick opening to traffic
Low tire noise
High friction with proper selection of aggregates
Ability to be recycled
Thin overlays are commonly used to repair a variety of different types of pavement distress. Thin overlays only marginally increase the load carrying capability of the roadway and should not be used to repair pavements that have damage caused by traffic loads.