Tarmac and asphalt are typically long-lasting road surfaces, and some of our oldest roads are based on foundations that are over a decade old.
Despite this, asphalt does not last forever, and as they are huge surfaces constantly exposed to the elements, damage to the roads is inevitable, as can be seen by the potholes, alligator cracking and uneven surfaces seen on many major roads.
Asphalt surfaces are typically robust, and most damage that you see is often the cumulative result of a range of causes. If a road is damaged so much that it is unsafe to travel on, then road surfacing companies need to be contacted to either patch the road or replace the damaged surface.
Here are some of the main reasons a road may become seriously damaged in the first place.
Roads are intended to make driving easier. However heavier vehicles can also put a lot of pressure on the surface itself. This consistent stress can cause weaknesses to emerge in the road surface, which as a result causes cracking.
This puts the cracked surface at risk of breaking off entirely and forming a pothole.
Water is one of the biggest causes of damage for road surfaces and is the reason why tarmac seals and pavement preservation is needed to avoid significant damage to the road surface.
If the surface is cracked, which can happen over time or as the result of particularly heavy pressures on the road, water seeps in and weakens the base course layer, which causes depressions.
What is often an issue is that if that base layer is damaged, the road will continually have problems with traffic load and be more vulnerable to cracks and potholes until the road is completely repaved.
Asphalt as a surface consists of a binder which sticks the rock, aggregate and sand that makes up the surface together. Over a long time, ultraviolet rays can dissolve this binder, causing the road to more closely resemble a loose arrangement of gravel than a road.
Once the road starts ravelling, it is time to resurface.
Have you ever wondered why road surfaces are black when they are new and gradually become a lighter grey as they age? The reason for this is exposure to oxygen, which gradually breaks down the asphalt layer and causes the surface to be less flexible.
Eventually, the tarmac layer is closer to concrete than its original state and is more susceptible to being cracked under heavy loads.
Parked cars can sometimes leak oil, which in small amounts and cleaned quickly is not always an issue, but the longer it sits on the asphalt the more it will seep in and ruin the top layers, as well as being exceptionally difficult to repair or remove.
The Earth Itself
Despite how it may feel, the earth is consistently moving on tectonic plates, and this, along with earthquakes and other natural phenomena, can cause the surface under a road to shift and settle over time, which in itself can cause cracks, sinkholes and other major damage.