The formation of these potholes is a complex process which can be caused both by nature and by road construction. Most potholes appear in spring, as a result of the freeze/ thaw action that follows winter.
Roadways are built in layers, starting with compacted earth and gravel for drainage. All layers are covered with asphalt, which is supposed to repel water and redirect it into drains.
Potholes form because asphalt surfaces eventually crack under the heat of the day and the constant stresses of traffic.
1. Potholes begin after snow or rain seeps into the soil below the road surface.
2. The moisture freezes when temperatures cool to freezing at night. The water becomes ice, causing the ground to expand and push the pavement up.
3. As temperatures rise, the ground returns to normal level but the pavement often remains raised. This creates a gap between the pavement and the ground below it.
4. When vehicles drive over this cavity, the weight of the traffic causes the pavement surface to crack and fall into the hollow space, leading to the birth of another pothole.
Once a pothole forms, it can grow up to a depth of several feet. Potholes put a huge strain on your car’s suspension and shocks. With rain and snow water accelerating the process and creating a trap for vehicles, it can cause expensive damage to a car. Repairing potholes in time can reduce damage to cars and reduce the chance of accidents.
There are two common repair methods. The first one is called “cold winter mix,” which, as the name implies, is commonly used in winter seasons. It is a temporary fix, where a soft asphalt patch is poured into the pothole after any loose debris is removed. The process is kind of like a dentist filling a cavity. However, the potholes are expected to return in the spring season.
Another more permanent fix is called “hot summer mix.” It uses a combination of road-grade asphalt and aggregate of various materials like sand, gravel, crushed stone, slag, recycled concrete and geosynthetic aggregates, and has to be applied during warm and dry weather. This combination is designed to last for years.