PAVEMENT PROBLEMS

TYPES OF PROBLEMS

ALLIGATOR CRACKING

SLIPPAGE CRACKING

SHRINKAGE CRACKING

REFLECTIVE CRACKING

POTHOLES

DEPRESSION

RUTTING

RAVELING

ALLIGATOR CRACKING

A series of cracks that form a grouping of small pieces resembling an alligator’s skin, alligator cracking can be caused by a pavement structure that is not sufficient for the weight of the loads or by oxidation, which causes a loss of pavement resiliency.

FIX: Because a structural failure is taking place the only possible solution to alligatoring is to perform a full-depth patch.

SLIPPAGE CRACKING

Slippage cracks are crescent shaped tears in the pavement. A surface layer of asphalt that was installed with a poor bond over the lower layer of asphalt is the usual cause of this damage

FIX: All of the areas exhibiting the “stretch marks” will need to be removed and will require a partial or full depth patch.

SHRINKAGE CRACKING

Shrinkage or block cracks are interconnected cracks that form groups of large blocks with cracks that usually intersect each other at right angles. The asphalt mix losing its flexibility due to age and oxidation normally causes this type of cracking

FIX: For less severe cracks (less than 1/2 inch) crack sealing will prevent the further entry of moisture into the subgrade. If the cracks are more severe the removal of the cracked pavement layer followed by an overlay may be required.

REFLECTIVE CRACKING

This type of crack occurs in areas that have been resurfaced. The cracks in the original pavement continue to move and eventually reflect upward through the new asphalt layer

FIX: Less severe cracks measuring 1/2 inch or less can be sealed to prevent moisture from entering into the sub grade. More severe cracks should be fixed by removing the cracked pavement layer and replacing it with an overlay.

POTHOLES

These are small bowl-shaped holes from which the asphalt surface is missing. A weak area in the pavement structure, water infiltration to the base, poor maintenance, or asphalt material problems can cause potholes.

FIX: Full depth replacement patch

DEPRESSION

Depressions are small low areas in the pavement that typically hold water longer than the remainder of the pavement. These can be caused by poor construction or from settlement somewhere in the pavement structure.

FIX: Depending on the severity of the depression the asphalt may have to be removed and replaced (severe). Less severe depressions can be fixed by applying a thin surface patch or infrared patch

RUTTING

Pavement depressions in the wheel paths are called rutting. When the asphalt pavement is displaced under traffic or an unstable asphalt mix is installed, there is a good likelihood the rutting will occur.

FIX: If rutting is minor or if it has stabilized, the depressions can be filled and overlaid. If the deformations are severe, the rutted area should be removed and replaced with suitable material

RAVELING

Raveling is a separation of the aggregate base (stone) from the pavement surface, giving it a rough texture. An inferior asphalt mix, age hardening, lack of proper compaction, or construction of the pavement during bad weather can all contribute to pavement raveling

FIX: Apply a thin hot-mix overlay. Other solutions could include: sand seal, chip seal, slurry seal or micro-surfacing.

REFERENCES

http://www.pavemanpro.com/article/identifying_asphalt_pavement_defects/

http://www.jennite.com/problems_causes/

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