However, knowing what to do can save thousands of dollars in the long run.

There are three common types of pavement maintenance—and one not-so-common: Common Pavement Maintenance: • Pothole repair • Crack filling, and • Surface Treatment. Not-So-Common Pavement Maintenance: • Keeping grass off the pavement edge

To know when and whether or not to use any of these, you must first understand a little about the type of problems pavements have.

The Most Common Pavement Problems

Alligator or fatigue cracking Too much or too heavy traffic on pavement causes it to pull apart. The result is fatigue or alligator cracking, similar to the photo at right. The pattern is like alligator skin or chicken wire fencing. This type of failure is caused due to a lack of enough asphalt and rock base for the loads in service. There is no effective solution for this other than to replace the damaged pavement with a new section built to withstand the loading. Special loading situations—commonly found around dumpsters—may require a concrete pad for adequate foundation strength. If left alone, water will seep through the cracks, undermine the base and soil underneath the problem area, and continue to get worse, eventually making a good-sized pothole. Block cracking/Shrinkage cracks Cracks in this type of pattern usually intersect each other at nearly right angles—large ‘blocks.’ The pattern may start out at a 20 foot spacing, but over time advances to a much smaller spacing, perhaps as small as 1 foot. This is due to weathering of the pavement—where it hardens over several years.

Longitudinal and Transverse Cracks
Cracks that occur along the construction joints, and at right angles to these joints. The joints are the weakest point of any asphalt pavement, and here’s where the cracks normally appear first.

Fuel spills
Petroleum products may leak from cars, especially older ones. In a parking lot, the spillage area is generally in a 3-foot by 3-foot section of the parking stall. The petroleum product -- gasoline, motor oil, antifreeze, etc. -- penetrates the asphalt, softens and weakens it. There are four simple but effective actions you can take to help assure longer life and service from your pavement.

These are: Clean and seal cracks as they occur; Keep grass off pavement edges, Repair Potholes as they occur; Use a surface treatment every 5-7 years.

1. Crack cleaning and sealing.
Unfilled cracks tend to get worse over time, allowing more water, grass, dirt and debris to enter. Water will eventually erode the subgrade material, leading to a localized pavement failure – a ‘pothole.’ Dirt and debris will aid in breaking down the edges of the cracks over the expansion and contraction cycles through temperature extremes.

Here’s a simple procedure for crack repair.

1. Remove grass and surface dirt/debris from cracks with a weed-eater and hand-held power blower. An edger may be used on larger cracks with care, or they may need to be routed.

2. Apply a weed-killer and soil sterilant to the crack to retard the growth of any vegetation. This is readily available from local farm and garden supply stores, and can be applied with a small hand-pump garden sprayer.

3. When the cracks are clean, apply a crack filler material and strike-off flush to the pavement surface with a squeegee. (Dow Corning 890- SL is an easy-to-use cold-pour product.Commercial-grade hot-placed products may also be used, but are generally cost-effective only for larger applications.) Cure as per the manufacturer’s instructions.

Aside from drainage improvements, crack cleaning and filling is probably the most important maintenance item that you can perform.

2. Remove grass from pavement shoulders.
Oftentimes grass is allowed to grow over the edge of a pavement. This hurts the pavement structure in two ways: first, the grass will break the pavement by expanding the cracks; second, the grass will slow down water as it drains off the pavement surface, often causing water to stand near the pavement edge. Poor drainage is probably the most destructive element facing most pavements.

To help this situation, use a small tractor with a blade or other similar piece of equipment to remove grass from the pavement edges. Assure that there is a small ‘lip’ around the edge of the pavement that allows water to drain away from the area. This lip should be no greater than 1.5 inches deep. Maintain this not less than bi-monthly,
and more often during high-growth seasons.

3. Pothole Repair Potholes only get worse over time. There are two general approaches to pothole repair: cold patch and hot mix full-depth.

Cold-patch repairs use a variety of commercial products that are placed loosely in a pothole, usually mounded, then hand tamped and allowed to final compaction by traffic. Cold patch materials will do for short-term repair, however they are not usually considered viable long-term solutions because they do not address the root problem: what caused the pothole in the first place?

Full-depth hot mix repair begins usually with a saw-cut 12 inches beyond the damaged area on all sides, and removal of all material down to solid dirt below the pothole. The area is allowed to dry, then is built back up to the required grade with an adequate base course (small rocks) topped with the new hot-mix asphalt, properly placed and compacted. By removing the soft subgrade, and by placing an adequate layer of small rocks (base course) the problem that caused the pothole in the first place is usually corrected so that it does not recur. A full depth repair should always be used prior to placing a new overlay.

Next Issue: Surface Treatments and How to Choose the Right Contractor.

Hearthstone Property Group, LLC
625 Beesley Road
Murfreesboro, TN 37128
Emergency Hotline: 615.890.4651
FAX: 615.848.1581
Email: hearthstone@comcast.net
www.hearthstone.net