The life span of asphalt pavement depends mainly on these factors: a good foundation (base and subbase), the asphalt mix itself, the thickness of the installation, and quality of construction. Water, oxidation (drying due to sun), and traffic overloading can slowly erode your pavement investment. Proper maintenance should include measures to prevent water penetration and oxidation from eroding the surface and pavement foundation.

Patching, cracksealing, sealcoating and overlays are the primary maintenance techniques. Patching corrects local deficiencies. Cracksealing and sealcoating help prevent water and oxidation damage, thereby helping extend the life of asphalt pavement. An asphalt overlay does as well, but also adds strength, durability, and a new, smooth, free-draining surface.

These preventative measures prevent costly repairs/early replacement, and significantly reduce the overall cost of the pavement. Each of these techniques are described briefly here:

Patching becomes necessary when the pavement's surface or base has been overloaded or deteriorated in localized areas.

Surface deterioration: Typically apparent by the presence of localized potholes. If there is no large scale cracking typically surface patching is all that is required. In order to maintain the integrity of smoothness and drainage, milling the surface prior to patching is recommended.

Base deterioration: If the base is not properly supporting the pavement loading, stress cracking will likely appear. When this occurs the pavement should be cut out and removed, the base inspected for soundness and replaced if necessary, and the asphalt surface replaced full-depth.

Cracksealing helps seal the pavement to keep water on the surface and from not rapidly entering the base layer where it begins its damage. Thermal cracking will develop in our climate because the asphalt expands and contracts from temperature fluctuations as the seasons change. Cracks should be sealed with a rubberized sealant after the edges have been routed to ensure maximize adhesion.

Sealcoating- The most common seal coats in the Upper Midwest are asphalt emulsion and hot oil/chip-rock seals:

Asphalt emulsion seal coats appear as black paint and are generally recommended for residential applications. Emulsion seal coats generally costs less than hot oil/chip-rock seal coats, but are less durable and require applications more frequently. Once applied, it is difficult to switch to another maintenance method until worn.

Hot Oil/Chip-Rock seal coats are often chosen for commercial/industrial and roadway pavement maintenance. This method spreads a cover aggregate over a uniform layer of hot asphalt emulsion, creating a new wearing surface.

Overlays adds a layer of new asphalt 1.5 to 2.5 inches thick over the roadway or parking lot. Overlays take seal coating a step further, adding both strength and improving curb appeal and drainage, as a new smooth surface is applied to your existing parking area or roadway. Before the overlay is installed, damaged areas must be repaired, otherwise existing cracks, holes, or weak areas may deflect up into the new surface.