CRACKSEALING

Cracksealing
Asphalt cracking is caused primarily by the effects of the sun and moisture.
The sun oxidizes asphalt causing shrinkage and creating separations which causes cracking.

Moisture is then able to reach the pavement's subbase and weaken it. Traffic soon begins to deteriorate the pavement around the crack, creating a larger problem, the infamous pothole.

Proper attention to cracks will prevent the problems from spreading and double the life of the pavement.  Treating the problem while it is still small will pay big dividends later by delaying costly resurfacing.

Benefits of Cracksealing
Cracksealing is our first defense against pavement deterioration because it offers several important benefits.

Protects the Base/Subbase
A good pavement needs a sound base and subbase.
Effective cracksealing keeps water from entering and weakening these areas.
This weakness can result in loss of structural support, which in turn can result in additional cracking or faulting (vertical differential settlement at the cracks).

Preserves the Pavement Adjacent to the Cracks
Cracks that are properly cleaned and sealed contain material that firmly adheres to the sides year-round, during times of expansion and contraction.
Without this material the adjacent pavement would have increased exposure to the elements, resulting in increased oxidation of the binder, hardening, and secondary cracking along the main crack.

Eliminate Damaging Effects of Sand, Stone, and Dirt
When sand, stone, and dirt get into the crack, they can restrict crack closure during warm weather. 

Also, they can cause compressive stresses at the crack faces that result in spalling and loosening of the asphalts aggregates.  In some highly oxidized pavements these stresses can even cause pavement lipping, which is the upheaval of pavement at transverse cracks.

Extends Pavement Life and Cost-Effectiveness
By sealing cracks, the contractor or agency exerts some control over base and subbase conditions, pavement interference, and crack growth, thereby extending the pavement's life.

Crack Types
There are seven (7) basic types of cracks.

• Reflective

• Block

• Edge

• Joint

• Slippage

• Thermal

• Fatigue or Alligator

Preparation and Application
Crack preparation always involves cleaning the crack, but can also require widening the crack through routing.

Singular cracks that are ¼ inch and wider (not in alligatored areas) are thoroughly cleaned of all foreign matter with an industrial heat lance air compressor.  We then seal the crack using the state-of-the-art oil-jacketed, cracksealing system with a rubberized hot-pour material.

In the oil-jacketed system the material is hydraulically agitated, then pressure fed through an oil-jacketed pump and injected under pressure directly into the crack at the optimum temperature. This prevents decomposition of the material which maximizes adhesion.  Today's hot-pour sealants are a blend of asphalt cements, extender oils, tackafiers, rubber antioxidants and fillers.

Routing
Another service that we provide is crack widening or "routing."
This is done to create a proper reservoir for the material to adhere to. It is created by using a routing machine, which makes a channel normally ½ inch deep by ½ inch wide. Then the channel is blown clean of dust and debris, thus ensuring a clean, dry surface for the material to be applied. 

The material is then injected into the reservoir and flush filled, thus sealing the crack and making it impossible for water to penetrate the base beneath the asphalt.
Widening is done with either a router or saw. There are many specific configurations that determine how much material is used, but sealant type determines the primary device used during application.

Concrete sealing
We also provide sealing of construction joints and saw joints in concrete driveways parking lots and streets.

Summary
The Illinois D.O.T. found that effective cracksealing reduced pothole formation and development of additional cracking significantly. Potholes and additional cracking formed at 75% to 80% of unsealed cracks compared to only 1% of the sealed cracks. The study concluded that effective cracksealing reduces future pavement deterioration.

Pavement Management Planning can be used to aid in keeping parking lots in better condition for longer times. Effective cracksealing provides documented and quantifiable life extensions in pavements due to restriction of surface water penetration into base and subbase layers. The pavement life extensions provided by effective cracksealing using appropriate preparation methods and quality hot-applied sealants can be used as an integral part of Pavement Management Planning in routine maintenance, preventative maintenance, deferred action and rehabilitation condition categories to achieve better performing parking lots at lesser costs.

(See our Pavement Management Planning Services)
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