Although asphalt is a water insoluble, it is not resistant to the effects of water pressure and movement. Freezing weather and ice can cause the asphalt bond to weaken, resulting in crack formations. Furthermore, asphalt is a flexible material, and expands and contracts as temperatures change. This attribute is actually another common cause for cracked asphalt pavements.
Other causes for asphalt cracks include water penetration, freeze-thaw cycles, inclement weather, and more. The most common practices for repairing asphalt cracks is to use crack sealers and fillers. Several factors will decide which type of material to use, like local climate, pavement conditions, and more.
Crack sealers are specialized treatment materials that are deposited into and above non-working asphalt pavement cracks. A non-working crack is a crack that shows less than 3 millimeters of horizontal movement per year. Aside from filling the crack, this process significantly decreases water infiltration and strengthens the adjacent pavements. There are many factors to consider when choosing a sealant for asphalt pavement cracks. A good product will have short preparation and cure times, and good cohesiveness, adhesiveness, elasticity, and flexibility. It should also have resistance to softening, aging, abrasion, weather, and flow. Products that meet these standards for sealers include rubberized asphalt, low modulus rubberized asphalt, and self-leveling silicone.
Crack fillers are standard treatment materials that are deposited into and above working cracks in asphalt pavement. Working cracks are cracks that shows more than 3 millimeters of horizontal movement per year. These materials are placed using unique configurations to prevent in-compressible solids and water infiltration from entering the crack. A good crack filler product will evince the same above-mentioned qualities of a crack sealer. Crack filler products that retain these qualities include asphalt emulsion, asphalt cement, fiber-ized asphalt, asphalt rubber, and polymer-modified emulsion.