What Causes Cracking On The Pavement & How To Repair Them?


There are many reasons that could cause a pavement to crack; for instance, freezing and thawing. At the same time, the method or manner in which the construction was done can equally determine cracking. And road geometry is another reason you need to consider.

All of these factors cause wear and tear, which eventually leads to cracking. While one of the solutions involve road repair with the right set of equipment, there are still various other ways to deal with pavement failure, depending on the type of cracking involved.

So, here are the typical types of cracking and what you can possibly do about them.

Reflection cracking

Otherwise known as crack uplifting, this type of cracking happens when new layers are applied to old, already cracked layers. Meanwhile, they can also occur in layers added to a stabilised foundation which is subject to shrinkage.

Solution

The best solution to deal with crack uplifting is a simple repair operation. It’s also the most economical way of dealing with the problem. However, this solution may potentially degrade quickly due to the reflection cracking phenomena.

Better known as cracks, reflection cracking is a result of the propagation of an existing crack found in a structural layer below the base course (binder and/or wearing course). If careful consideration of this framework is not done, the new tread will degrade soon.

Fatigue cracking

When there’s too much traffic, way above the permissible limit, the road experiences fatigue cracking. In this cracking process, ageing asphalt mixes accelerate the condition.

During the life cycle of the pavement, vehicular density will increase. When this occurs, the structure takes up more load cycles than what was initially expected by the road designers. And this is what leads to fatigue cracking on the road’s surface.

Solution

Typically, there are two types of fatigue cracking repair, the first one being for minor cracking.

The cracked pavement area is first removed and dug out, followed by the replacement of poor subgrade and enhance the drainage of that particular area if required. Then, you’ll patch over the repaired subgrade.

For large fatigue cracked areas, it means that it’s a sign of overall structural failure. You’ll have to patch it up with an HMA overlay over the whole pavement surface, and it has to be strong enough structurally to lift the anticipated loading due to the underlying fatigue cracking which has resulted in little to no strength.

Thermal cracking

From the name, this type of cracking system has its origin from temperature variations. Asphalt mixes have properties that vary based on temperature. These properties, therefore, can change drastically depending on the present weather conditions. One aggravating factor resulting in thermal cracking is the stiffening of the asphalt mixes.

Solution

Here, the load isn’t so much of an issue, as even when it’s constant, the asphalt mix will vary in resistance based on the temperature. However, you may decide to choose asphalt mixes based on their thermal properties. And this may as well be the first step to solving the thermal cracking problem.

Also, modifying the thickness of the asphalt may play a role in either combating thermal cracking or accelerating it. Therefore, you need to have the right thickness for it to work well.

Various chemical additions may equally help to solve the problem. However, thermal cracking is more prone in areas with extreme weather patterns and conditions. The type of concrete you use, and its thickness highly determines thermal cracking. Thus, you’ll need to balance everything correctly.

Pavement failure may potentially occur, and which is why executing the road construction process correctly is important from the very beginning. Hence, when doing so, ensure you’ve engaged with the right equipment provider for the required machinery to conduct road repair or construction smoothly.

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