Waterproof is the key to reducing damage to asphalt pavement

The various diseases that occur on asphalt pavement are related to the invasion of groundwater and surface water to varying degrees. Waterproofing is an important and even fundamental measure to improve the durability of asphalt concrete. One of the main reasons for water damage to asphalt pavement is the excessive porosity of asphalt mixture. According to the information, the void ratio is between 8% and 12%, and road water is most likely to invade the interior of the surface layer mixture. Once the asphalt surface layer contains a certain amount of water, the water will flow freely inside the asphalt mixture. In addition, the repeated action of vehicle loads generates hydraulic force in the water in the surface layer. This part of the water gradually invades the interface between asphalt and aggregate, causing the asphalt film to gradually detach from the surface of the aggregate, ultimately leading to the loss of adhesion between asphalt and aggregate, causing water damage and destruction. Therefore, the waterproofing of asphalt mixture requires raw materials and is also the key to reducing the damage to asphalt pavement.
Asphalt materials The asphalt materials used for asphalt pavement include petroleum asphalt, coal asphalt, liquid petroleum asphalt and asphalt lotion. The grade of asphalt materials used for various types of asphalt pavements should be determined based on factors such as the type of pavement, construction conditions, regional climate conditions, construction season, and the properties and size of mineral materials. However, when asphalt materials are heated (usually to 170 ℃~180 ℃ during production), the water in the pores will change from liquid to gas. Due to volume expansion, most of the water vapor will be discharged from the pores. As the surface tension of hot asphalt is very small and it has excellent wetting properties with dry aggregates, it will easily enter the pores of the aggregates, causing harmful water to evaporate and reducing the harm to asphalt pavement.