An asphalt pavement driveway adds value to any home just as an asphalt pavement parking lot adds value to a commercial lot. But to maintain that value and extend the property’s useful lifespan, a routine maintenance plan is key. It is necessary to obtaining a longer lifespan and greater cost-effectiveness when compared to complete restoration.
One method of preventive maintenance is the utilization of asphalt pavement sealers, which in turn makes minor rehabilitation and routine maintenance easier.
Asphalt pavement sealers are applied to protect the surface of asphalt from the corrosive effects of gasoline, diesel oil, motor oil, and grease that may come in contact with the asphalt surfaces.
Sealers also prolong the life of asphalt by decreasing oxidation and ultraviolet light bleaching as well as preventing moisture from entering the asphalt. The net effect is an extension of the performance life of new or existing asphalt.
While sealcoating is the first line of defense in preventive maintenance, crack filling and patching are also essential components.
Joints, cracks, and potholes occur when asphalt pavement has been allowed to deteriorate. These fractures allow water to penetrate the underlying pavement layers and create the need for a more expansive and expensive restoration.
What causes asphalt pavement to crack?
The primary cause of asphalt pavement cracking, assuming it was properly designed and constructed initially, is the penetration of water to the asphalt base.
This process begins with the oxidation of the pavement surface. This causes the asphalt to become dry and brittle, which leads to the erosion of the top layer of fine particles and the appearance of larger stones and small cracks on the surface. If left untreated, these cracks can grow and eventually allow water to penetrate the base of the pavement. This would cause movement and settling, leading to further cracking and the “alligator” appearance. When the pavement reaches this stage, the only option is removal and replacement of the old asphalt.
What are sealcoats?
There are several types of sealcoats. In the past, we have typically used either an asphalt emulsion or coal tar emulsion. We now proudly offer an asphalt emulsion from GuardTop sealcoat products because of its superior quality.
An asphalt seal coat is a smart and safe choice for pavement protection. It is attractive, environmentally sustainable, and nonflammable. Asphalt sealcoat gives a shiny, black appearance and looks as if a fresh coat of paint has been applied. Coal tar base sealcoat can lead to pavements appearing worn and gray.
In technical terms, an asphalt emulsion is a dark brown-black cementitious material, solid or semi-solid in consistency, in which the main constituents are bitumens which either occur in nature as such or are obtained as residue in petroleum oil refining, a process not involving cracking or thermal conversion. It is postulated that petroleum, the source of asphalt, originates from the decay of animal and marine life over millions of years, in an oxygen deficient but water containing marine environment.
A bulk asphalt emulsion is a concentrated mineral stabilized emulsion fortified with polymer and petroleum resins.
A mixed emulsion is 20 to 25 percent water and three to five pounds of sand per gallon.
Coal tar emulsion is a thick, black or brown liquid that is a byproduct of the carbonization of coal for the steel industry or the gasification of coal to make coal gas.
Although we generally use an asphalt emulsion sealcoat product, we will provide a coal tar product for sealcoating at the customer's request.
Sealcoats are designed for off highway use, where there are low traffic speeds and tight turning radiuses such as parking lots, schools, and housing developments.
How does sealcoating work?
Pavement sealers are designed to protect and beautify your asphalt driveway or parking lot. Sealcoating seals the asphalt pavement, preventing the oxidation and erosion of the top layer of the asphalt. On older asphalt pavements, sealcoating replaces fine particles lost from the asphalt surface due to oxidation. Sealcoating seals in small cracks, before they turn into large cracks, and prevents water from seeping down to the base material.
Sealcoating prevents weather damage, reduces maintenance costs, and adds years of life to the pavement.
What are some other benefits of sealcoating?
• Sealcoating helps protect the asphalt pavement from the sun as well as harmful spills such as oil and gasoline.
• Sealcoating leaves a smooth, clean surface that is ideal for sweeping, which lowers cleaning costs.
• Sealcoating provides an attractive black surface that is ideal for painting lines and other markers.
• Sealcoating costs pennies per square foot compared to the dollars needed to repair or replace damaged asphalt.
Do I need to sealcoat new asphalt pavement?
We recommend allowing new asphalt to cure for a minimum of 30 to 60 days. Once the asphalt is free from oils and sufficiently cured, a sealcoat can be applied.
After a surface has been sealed, it should be resealed every 3 to 4 years.
How long should we keep vehicles off the surface after sealing?
Please give the sealcoat 24 hours after the final application to cure prior to opening the area back up to traffic.
How should the asphalt be prepared before sealcoating?
Surfaces must be clean and free from all loose dirt and material. Pavement surfaces should be repaired with a suitable hot or cold asphalt mix. Cracks should be filled with hot or cold applied crack fillers. All gas, oil, and grease spots should also be treated and cleaned.
How is asphalt sealer applied?
Sealcoats are applied directly to the surface of an asphalt pavement by rubber squeegee, broom, or mechanical sprayer.
How many coats of sealer are required?
Two coats of sealer are applied initially. A third coat may also be necessary for high traffic areas such as entrances, exits, and drive lanes.
What are the benefits to using additives in sealer?
Additives can speed up the drying time for additional coats of sealer as well as help with sand suspension and reduce power steering marks.
Is sand required for application?
Clean silica sand should be included in the mix design. Sand provides slip resistance, helps with drying, and adds durability to the sealcoating material.