microsurfacing

Microsurfacing is a pavement preservation technique that applies a thin wearing surface composed of a polymer-modified asphalt emulsion combined with graded aggregate and mineral filler. The resulting layer seals minor surface cracks, improves skid resistance, restores texture, and extends the life of existing pavements without structural resurfacing.

The mixture is produced in a slurry plant or on site and delivered by specialized slurry or distributor trucks. It contains a polymer-modified asphalt emulsion, fine aggregate, cementitious or mineral filler, water, and performance additives. A dedicated spreader box provides a uniform, calibrated layer, typically about 3 to 6 millimeters (roughly 1/8 to 1/4 inch) thick. Curing occurs relatively quickly in suitable weather, allowing traffic to return after a short wait, often within a few hours.

Surface preparation is important and usually includes cleaning, removal of loose material, and sealing of cracks if necessary. The pavement should be in generally sound condition without major structural deficiencies, excessive deformation, or pumping.

Microsurfacing is applicable to asphalt and some concrete pavements, including highways, urban streets, and parking lots. It is not a substitute for structural repair and may not be suitable for severely distressed surfaces. Advantages include waterproofing, improved skid resistance, rapid return to service, and cost efficiency. Limitations include sensitivity to weather and traffic during curing, and variability in lifespan depending on traffic, climate, and substrate condition, typically offering several years of extended service.