How effective pavement maintenance not only saves your parking lot — but also saves money in the long run.
Well designed and constructed asphalt pavements can provide many years of useful service — if properly maintained. An effective asphalt maintenance program will dramatically increase the useful life of a parking lot, while postponing the need for the considerable expense and customer inconvenience that accompany reconstruction. Asphalt can be viewed in much the same way as wood. If wood is left untreated, it will be destroyed by elements of weather including sun, oxidation and water.
An effective preventive maintenance program will actually save money in the long run, while providing a surface that is attractive and easy to clean.
Roxanne Aiken, senior manager of Green Valley, Arizona-based Wilson Property Services, summarizes the value of good asphalt maintenance: “Regular sealcoating, striping and maintenance of our parking lots has prolonged the life of what we consider a major investment. In addition, our tenants and their customers see our consistent and timely maintenance as a reflection of the care we provide to our properties. Our tenants are proud to be in a property that looks its best.”
So what are the steps to extending the life cycle of asphalt pavements?
The first step in maintaining asphalt pavement is regular sweeping. Sweeping removes sand and grit that accumulates on the surface. If it is not removed, this grit will act as an abrasive. Over time it will remove the top stratum of pavement or surface treatment, and permit water intrusion into the pavement structure.
As pavement ages, cracks will begin to appear. These cracks should be addressed before any surface treatment is started. Crack sealing is one of the best early preventive maintenance measures to prolong asphalt life.
Paving engineers agree that “working” cracks a quarter of an inch and wider should be sealed. There is very little benefit in sealing “alligator” or fatigue type cracks, as these usually indicate base failure.
Prior to sealing, cracks must be dry and thoroughly cleaned with a high pressure air compressor. For parking lot or roadway use, a hot-applied, rubberized crack sealant is recommended.
For areas exhibiting base failure, the most effective repair is removal and replacement. Initial phase of the process is to saw cut outside the perimeter of the affected area. The distressed asphalt is excavated and the base is compacted and/or replaced. The edges of the existing pavement should then be tacked with SS1H asphalt emulsion. The repair is completed by placing the appropriate amount of hot mix asphalt, raking and properly compacting.
In low areas, it may be possible to perform a surface repair commonly known as “skin patching”. This procedure should only be used after making sure that the new patch will not interfere with drainage. The area is cleaned and tacked with a solid coat of SS1H emulsion. A thin layer of finely graded hot mix asphalt is then placed, raked and properly compacted.
If left untreated, asphalt parking lots will eventually be destroyed by elements of weather. Sun and oxidation dry out the asphalt mix and leave the pavement brittle. Loose stones begin to ravel from the asphalt and the surface becomes rough and faded. Rain and water from irrigation further erode the pavement’s cohesive strength.
Sealcoating will protect an asphalt pavement by sealing in the vital oils of the asphalt mix and sealing out sun, oxidation and water. Parking lot sealcoating is normally accomplished with two coats of a high grade asphalt emulsion applied by spray or squeegee.
Depending on traffic and usage, a parking lot should be sealed about every 3 years. It should be noted that, in addition to extending the pavement’s life, sealcoating improves the appearance of the parking lot with a uniform black color that is appealing to customers and tenants.
Keeping pavement markings fresh and sharp can improve both the appearance and the functionality of a parking lot. Fuzzy or faded markings may send an unclear and/or unsafe message.
“We believe that good pavement markings help keep our parking lots customer friendly,” says Matthew Baller, manager of Foothills Wal-Mart in Tucson, Arizona.
Care should be taken to establish the proper striping lay-out, and lines should be uniform. All legends, stenciling, and other traffic symbols should be accomplished with templates. It is important to make sure that striping complies with the requirements of the Americans with Disabilities Act (ADA), as well as all local ordinances.
Sweeping, crack sealing, asphalt repairs, sealcoating and striping are the main steps in a well-planned pavement maintenance program. A qualified pavement maintenance contractor can be a valuable partner in preparing a preventive maintenance schedule. Use their expertise in developing annual budgets and projections. You’ll be rewarded with cost savings and attractive, long-lasting parking lots.
— Dale Ford has over 35 years of experience in asphalt paving and maintenance. He now serves as a consultant with Tucson, Arizona-based Sunland Asphalt, a full range asphalt paving and maintenance contracting company serving the southwestern United States.