PROPER ASPHALT MAINTENANCE IS KEY TO PROLONGING THE LIFE AND AESTHETICS OF YOUR PROPERTY

Undeniably, the condition and appearance of your asphalt roadways, driveways, and parking lots is a major factor in the aesthetics of your property.

Asphalt is composed of mineral aggregates compacted into place and held together by petroleum-based asphalt cement, which acts as a glue or binder. While being a fine, cost effective product, asphalt is not maintenance free. Proper asphalt maintenance is essential to maintaining the life and appearance of your pavement surfaces.

Understanding the primary cause of asphalt failure will aid as you plan your pavement maintenance program. Assuming that the original roadway was constructed properly, the process of oxidation begins shortly after the asphalt has been installed. Left untreated, with time and age, the asphalt becomes dry and brittle allowing the aggregate to wear away causing cracks where water can penetrate into the base material. Water causes the base to move and settle causing further asphalt cracking or “alligatoring”. Once the asphalt reaches this stage the only remedy is patch repair or replacement of the damaged asphalt.

Below you will find a brief description of the four industry accepted asphalt maintenance procedures; patch repair, seal coating, asphalt overlay, and mill and mix.

REPAIR OPTIONS

The most common method of pavement maintenance is patch repair of isolated areas. The most frequently types of patches are; cut and repair, and overlay. Cut and repair, also known as saw cut repair, is a process where damaged asphalt is cut with a street saw creating a smooth straight edge around the perimeter of the repair area. Damaged asphalt is removed down to the base, usually a depth 1.5 to 2 times the depth of the original pavement thickness.  The condition of the base material is a critical factor in the quality of the repair. In the event that the base is compromised or nonexistent, the damaged area must be excavated and new base material installed and compacted to match the adjacent areas prior to paving with new asphalt. For best results, the patch should extend 12 inches in all directions beyond the damaged area, and cuts in squares and rectangles yield the best results. Multiple cuts and angles create weak points within the repair.

Overlay repair, is usually selected as a cost effective repair in areas where water flow and heavy vehicle traffic do not pose a concern. Usually costing half as much as a cut and repair patch, the damaged area is thoroughly cleaned using hi powered equipment to remove loose debris. A coat of “tack” adhesive is applied to the damaged pavement prior to the overlay of asphalt. Generally, 1 inch of asphalt is the standard for an overlay patch. For best results, the patch should extend 12 inches in all directions beyond the damaged area.

SEAL COATING

Left unsealed, your pavement will decompose due to sun, rain and petroleum spills of fuel, oil and solvents which attack the pavement and seep deep into the surface compromising asphalt cement and reducing adhesion. You can easily see the decomposition begin as your once rich black asphalt turns to gray. With the harsh sun and damaging UV rays that we all contend with here in Florida, seal-coating is mandatory to extending the life and appearance of any asphalt surface.

The sealer we apply at Duraseal Asphalt Sealing & Paving is manufactured locally in west central Florida by GemSeal. Founded in 1947 as Mariani Asphalt, the sealer division was incorporated in 1957 to produce the finest coal tar pitch emulsion in the industry. GemSeal is made of high grade ball clays, water, refined coal tar and a proprietary emulsifier, milled into a coal tar emulsion yielding a paint like coating. Sealer insulates the asphalt from damaging elements while significantly reducing the normal aging cycle of asphalt. GemSeal is the oldest sealer brand in continuous existence in the industry.

Sealer should be applied to new asphalt after a curing time no less than 12 months, and no longer than 24 months of paving. Future applications should be scheduled at 3 to 5 year intervals, or whenever the aesthetics are not up to the standards of the property.

PAVING OPTIONS

ASPHALT OVERLAY

Asphalt overlay is a cost effective process that provides a new surface of asphalt over the entire roadway. The rule of thumb is that asphalt overlays should be applied as 1 inch, 1.5 inch or 2 inch lifts. Surface preparation prior to overlay is a major factor in the success of the job. Areas of base failure, crumbling, and severe cracking should be repaired prior to overlay to prevent the previously damaged areas from showing through the new asphalt.

Utility lids of all shapes and sizes can be easily brought to level with the new surface with the installation of a riser ring that is designed to provide proper lift to match the new asphalt.

To insure a proper job, facilitate proper drainage, and eliminate trip hazards, transition areas should be milled to a minimum 1 inch below the original surface. Never feather new asphalt to match an existing structure as this will severely weaken the strength of the overlay. Likewise, it is always recommended that the original pavement be milled to I inch below any adjacent surfaces such as curbing and sidewalks, prior to the overlay.

Recently, the use of reinforcing fabric as part of the overlay process has garnered a lot of attention. While in theory, reinforcing fabric appears to be an excellent addition to the process, the negatives such as slippage between the new overlay and the original surface, while rare have been reported after the overlay begins to age. In addition, the inevitable patching and disposal of aged fabric reinforced asphalt creates new challenges as the fabric prohibits the asphalt from being recycled resulting in higher dumping costs.

MILL and MIX

Mill and Mix, often referred to as Pulverize in Place, is an excellent solution to situations such as base failure cracking or a roadway that is too high due to multiple overlays. Mill and Mix is a process where your asphalt pavement is reduced to base sized particles. Using a milling machine set to a specific depth, the asphalt and base are ground or pulverized together resulting in a “recycled” material that can be graded like new base. Experience has taught us that the combination of asphalt and base yields a base material stronger and more durable than virgin base as used in new construction. This recycled base material enables the paving contractor to return the roadway to its original elevation and reshape it as required to promote improved drainage and conform to new and existing structures. Once graded and compacted, the base is treated with tack adhesive to promote adhesion between the base and new asphalt. The final step of the process is the installation of new asphalt resulting in a surface similar too, if not better than, a complete new roadway.

Other than a excavating and building a new roadway at significant expense, the Mill and Mix process is the only way to correct and eliminate severe cracking such as that found here in Florida where the use of soil cement base is prevalent. The obvious benefits of Mill and Mix are the elimination of the costly process of exporting excavated asphalt and base, and importing new base material. Time is also a consideration when Mill and Mix can be completed in a fraction of the time required for new roadway construction.

For more information or for a free evaluation of your asphalt pavement, contact the experts at Duraseal Asphalt Sealing & Paving and trust them to put their 25 years of excellent service to work for you.