Common Asphalt Problems - What you should know and how we fix them

Common Asphalt Problems

We must first know what asphalt is made of, what asphalt can and can't do,
what to expect from asphalt and asphalt maintenance requirements

THE ASPHALT SHORT STORY
Asphalt consists of rock, sand, tar and bitumen. Rock and sand give asphalt the compressive strength that is needed with heavy compressive loads. Tar and bitumen are liquid components which act as a binder for the aggregate and remain flexible. It is flexibility that is very attractive in asphalt due to ground movement during freeze/thaw cycles that occur in the Northern climates. Over time exposure to the elements (sun, heat, UV, freeze/thaw, rain, snow and chlorides cause the asphalt to "dry out" and lose the flexibility that asphalt offers. When you see asphalt surfaces loose their deep black color you know that the tar and bitumen are removed and the lighter gray color indicates that the asphalt surfaces is loosing is most desirable quality, flexibility. Especially in the Northern climates where more flexibility is needed to ward off cracks that quickly evolve into depressions and potholes.

Sealcoating asphalt every 2-4 years will ensure surface degradation will be non-existent and the likelihood of more serious asphalt failures or replacement will be warded off for as long as regular maintenance takes place.

The most common visible asphalt problems and remedial actions are listed below

Surface fissures: Surface fissures little spider cracks visible on the asphalt surface. Fissures are caused by inadequate size aggregate.

What we do to correct it: We use a trowel grade asphalt and skim coat the suspect surface area. Trowel grade asphalt surfacing material has 1/16 inch aggregate with a fortified bonding agent to get like oil base to bond to like oil base material.

Small Cracks: Small cracks are defined by cracks less than 3/8 inch wide.

What we do to repair them: We commonly grind them out and fill them with a premium grade filler. After proper cure out we then sealcoat over them.

Large Cracks: Large cracks are defined by cracks greater than 3/8 inch width.

What we do to repair them: We typically grind the rough edges and either fill the crack to a depth of 1/2 inch or multi-ply asphaltic "rope" and melt to ensure slight overfilling of the cracks. After proper cure out we then sealcoat over them.

Dips, hollows: Dips and hollows are created when the substrate of the asphalt has settled. Asphalt bends more readily than concrete which enables hollows.

What we do to repair them: We use an asphaltic trowel grade skim coat to build. More than 1/4 require multi applications.

Cracked Areas with Dips and Hollows: This is an area where there are multiple cracks leading to a central low location.

What we do to repair them: Asphalt, unlike concrete, is easy to bond unto itself and asphalt doesn't transfer cracks as readily as concrete because of asphaltic flexibility. Being an oil based product you can re-emulsify or renew it with heat. We heat the substrate or faulty area(s) to about 400 degrees to get it aqueous and apply a heated cold mix to grade as the separate entities cool they bond thus forming one. Not much different than epoxies except one is chemical and one is temperate. Cold mix is more sensitive to thermal rises than hot mix because of the inhibitors.. We then skim coat trowel grade over the seams to make it appear as seamless as possible. After proper cure out we then sealcoat over the area(s).

*Transforming Asphalt to Concrete: Making asphalt act like concrete, shutting off the oil base qualities of asphalt.

Why would somebody do this? The most advantageous aspect of asphalt over concrete is cost. The only other side benefit that I know of is flexibility. OK, asphalt is cheap compared to concrete. Cheaper to buy because of raw materials and cheaper to install because of asphalts inherent.....flexibility. With asphalt installations the aspects of asphalt make prep work much less critical. The lists are long. However, asphalt is more susceptible to degradation. These lists are even longer.

And...why would somebody do this? To beautify and protect. When you use an asphaltic substrate and give it cementitious topcoats you get the best of both worlds. Flexible long forming matrix' substates with limited amount of degrading surface exposures. Best of both Worlds.

How can this happen? You can take away asphaltic attributes by shutting off asphaltic properties with a topcoating. When you topcoat with a waterborne aliphatic you shut of oil based properties, oil base properties won't let concrete bond with asphalt. When you bond the aliphatic to asphalt, which is possible to do you shut off oil based properties and you can bond cementitious to aliphatic. This procedure allows you to let your asphalt act like concrete which can give you greater beauty, protection and lastability.

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