Pavement preservation techniques
There are many different techniques for preserving asphalt pavements in Minneapolis, MN including:
- crack sealing and crack filling
- seal treatments
- slurry seal and microsurfacing
Crack sealing and crack filling
There are two approaches to addressing cracks: crack sealing and crack filling. Crack sealing is the more involved and permanent method. It is intended to keep water and other unwanted material from using the crack as an entrance. Crack sealing is needed when there is movement of the pavement at the crack. Crack filling doesn’t require much prep work and is intended to minimize the amount of water entering the pavement. Both sealing and filling extend pavement life by reducing stripping and fatigue. The earlier you can apply one of these methods, the better chance there will be of extending the pavement life in Minneapolis, MN.
Sand and scrub seals are sprayed applications of asphalt emulsions followed by using sand or fine chips to cover the asphalt. Scrub seals use a broom or squeegee to force the emulsion into the cracks before the cover material is applied. These sealing operations use the same equipment as chip sealing, with scrub seals needing the addition of a broom mechanism. Sand seals typically add 3 or 4 years of pavement life while scrub seals can add between 4 to 6 years of service.
Chip seals are done by applying liquid asphalt to the pavement surface followed immediately by cover material made of chips. This is followed by subsequent rolling and brooming. Chip seals are a very commonly used preservation technique. If needed, additional applications can be used for additional protection. A cape seal is a combination technique that consists of a single chip seal followed up by a slurry seal. The chip seal provides crack sealing while the slurry seal upgrades the ride quality.
Slurry seal and microsurfacing
Slurry seals are a mixture of many different materials. These include well-graded fine aggregate, mineral filler, asphalt emulsion and water. They are used as asphalt surface treatments and the application is usually the thickness of the largest mixture particle. Slurry seals do not increase the structural capacity of a pavement but can help reduce surface damage caused by oxidation, seal unwanted cracks, and improve skid resistance.
Micro-surfacing is a designed mixture of polymer-modified emulsion, aggregate, mineral filler, and water. It is used to fill ruts and improve skid resistance.