>Full-depth Asphalt Repair – Carolina Asphalt

Solution: Full-depth asphalt repair

Alligator cracking is a visual sign that the existing pavement structure can no longer support the loads exerted on it. The entire area must be excavated and replaced with a full-depth layer of new asphalt. It would be less expensive to cut out the damaged areas and replace with a layer of crushed stone and new asphalt, but it takes several days for stone to set up properly and it must be flooded with water to achieve density. This is usually not feasible in a repair scenario for a pavement system that is currently in use (see seminar section of new construction).

The networked cracks on the top surface are an indication of instability in the lower levels of the pavement system. For this reason, the area must be excavated 1 beyond the cracks on the surface. Each patch should be a minimum of 4 wide to accommodate the full width of a small steel wheeled roller.

Areas to be repaired should be rectangular and encompass the entire cracked area. Wherever feasible, it is best to combine several small areas in to one large repair. A series of small patches with intact asphalt in between, left untouched, will usually create more repairs in the near future. The base layer in the untouched areas will be less stable than the repaired areas and will be pounded by traffic that rolls from a strong to a weaker surface.

Property Manager Hint: Walk the entire parking lot with an estimator and place small paint dots on the outer edges of all cracked areas. Once these have all been sprayed, stand back and create a series of rectangles to encompass the cracked areas. Number and measure each area and note on a site plan.

The design depth of the repair is dependent on the traffic loads, the strength of the sub-grade and the years it is expected to last. Evaluate these three factors for a particular pavement system when choosing a design depth of pavement.

The number of heavy truck axle loads exerted on the pavement system is a measure of the traffic loading. Car traffic is almost irrelevant in this consideration since heavy truck loads can be equivalent to 30,000 car loadings.

The strength of the sub-grade most often is visually measured in a proofroll process. The pavement system is excavated and removed and a loaded truck is slowly driven over the sub-grade. Any significant deflection is marked and measured.

The depth of the repair is directly related to the life of the repair. The deeper the repair the longer it will last. Carolina Asphalt has installed thousands of tons of asphalt repairs forover 20 years in the Carolinas, and our experience has given us the following guidelines for depth of repairs. 4 depth: Car traffic only, no truck traffic expected

Parking spaces in an apartment complex with a centralized dumpster in the front of the property would be a good example.

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>Full-depth Asphalt Repair - Carolina Asphalt