Preventive maintenance of pavement means to timely discover signs of slight damage and disease on the pavement through regular road condition surveys, analyze and study their causes, and take protective maintenance measures accordingly to prevent the further expansion of minor diseases, so as to slow down the deterioration of pavement performance and keep the pavement always In good service condition.

Preventive maintenance is for roads that have not yet suffered serious damage and is generally carried out 5 to 7 years after the road is put into operation. The purpose of preventive maintenance is to improve and restore the surface function of the pavement and prevent further deterioration of the disease. Foreign experience shows that taking effective preventive maintenance measures can not only improve the quality of roads, but also have good economic benefits, greatly extending the service life of roads and saving maintenance funds by more than 50%. The purpose of highway maintenance is to always keep the road condition in good condition, maintain the normal use functions of the highway, eliminate diseases and hidden dangers that occur during use, and extend its service life.

If roads are poorly maintained or out of maintenance, road conditions will inevitably deteriorate quickly and road traffic will inevitably be blocked. Therefore, great attention must be paid to maintenance work. In the entire maintenance work, pavement maintenance is the central link of highway maintenance work. The quality of pavement maintenance is the primary object of highway maintenance quality assessment. This is because the road surface is a structural layer that directly bears the driving load and natural factors, and is related to the driving load. Is it safe, fast, economical and comfortable.

At present, about 75% of the expressways that have been built in our country are semi-rigid base high-grade asphalt concrete surface structures. In Guangdong Province, this proportion is as high as 95%. After the completion of these expressways, they have been affected by the rapid growth of traffic volume, large-scale vehicles, and serious overloading. , traffic channelization and water damage, etc., the road surface has suffered early damage to varying degrees, resulting in arduous maintenance tasks. In addition, as the mileage of highways increases and the usage time increases, the road surface will inevitably be damaged, and the amount of maintenance work will become larger and larger. It can be expected that in the future, my country's highways will shift from construction as the main focus to both construction and maintenance, and gradually focus on maintenance.

The "Technical Specifications for Highway Maintenance" clearly states that highway maintenance work must implement the policy of "prevention first, combining prevention and control". However, the reality is that highway maintenance management is insufficient, diseases are not dealt with in a timely manner, and preventive maintenance is not in place; coupled with traffic Rapid growth in traffic volume, early construction defects, temperature changes, water effects, etc. have resulted in most expressways not reaching their design life and the road surface has been severely damaged. Implementing preventive pavement maintenance on highways in advance of major overhauls can repair minor pavement diseases in a timely manner without causing serious damage, thereby reducing the number of milling and renovations, saving overhaul costs, extending the service life of the pavement, and maintaining good service condition of the pavement. Therefore, it is an urgent need for the development of highways in my country to research and develop preventive maintenance technology and management models for highway asphalt pavements and implement preventive maintenance management of highways.