Pavement pothole refers to the pothole caused by partial peeling of pavement aggregate under the action of traffic load and natural factors.

￭ The hazard of potholes

Pothole is one of the most common and harmful bitumen pavement diseases. Especially after rainfall or repeated freezing and thawing of snow water at the turn of winter and spring, a large number of potholes and grooves will be damaged, and with the repeated action of vehicle load, the damaged surface will gradually increase and deepen, which will directly lead to the decrease of road roughness, seriously affecting the driving comfort and safety of cars.

￭ The cause of potholes

The generation of potholes on bitumen pavement usually has a time process of formation, which starts with local cracks and then cracks and loosens, gradually forming potholes under driving load and rainwater and other factors.

Common reasons include the following:

Water damage

Water damage is the most important factor of pitting on asphalt concrete pavement. Water has a softening effect on asphalt concrete (the increase of water content of asphalt mixture reduces its strength and stiffness), peeling effect (reduces the adhesion between asphalt and aggregate) and scouring effect (the hydrodynamic pressure under the action of load constantly scour fine materials). Causes the asphalt concrete to loose, thus forming the pit trough.

Pavement aging

Because of the aging phenomenon of asphalt mixture, the adhesion between asphalt and stone is poor, and the viscosity of cement decreases. The former pavement material is gravel. The lack of bite force between gravel and the poor water stability of asphalt mixture is easy to cause asphalt mixture pavement diseases under comprehensive factors such as load and water.

Backward construction technology

There are two types of pits caused by improper temperature control of the mixture. In one case, the mixture temperature is too high during construction, and the asphalt will age in the heating process, resulting in the reduction of cohesive force, the increase of brittleness, and the weak bond. Under the action of driving load, pits and grooves will be formed. Another case is the mixture temperature is too low, especially the bottom of the mixture due to contact with the lower layer cooling too fast, can not achieve good compaction effect.

Potholes caused by traffic

The traffic volume is much larger than before, and over-loading transport is very serious. It leads to premature fatigue cracks in the pavement structure and develops into pits and grooves under the action of rain erosion. Vehicle accident stopover causes fuel oil leakage, dissolves asphalt, and makes asphalt and aggregate lose their cohesive force, gradually spalling and forming pits; A pit formed when the road surface is crushed by a jack while a vehicle is changing tires.

￭ Early prevention of potholes

1. Strengthen road drainage so that the surface rainwater can drain away from the road timely.

2. Strengthen the management measures of vehicles to prevent overloading.

3. Treat the early occurrence of pits timely to prevent the disease from continuing to develop.