High-grade asphalt roads mainly include national-level cross-border highways, expressways, trunk provincial roads and key municipal roads, which are constructed in accordance with the Code for Design of Highway Asphalt Pavement (JTG D50-2017), the Test Code for Asphalt and Asphalt Mixture in Highway Engineering (JTG 3410-2025) and other industry standards. The pavement shall meet the core requirements of high traffic volume, heavy traffic, long life, high safety and low disease, and at the same time adapt to the complex construction environment such as plateau, mountain area and large temperature difference. The standardization requirements shall be implemented from six dimensions: pavement performance, structural design, raw material quality, construction technology, quality acceptance and later operation and maintenance. 

Overall Performance Requirements Criteria 

High-grade asphalt pavement should have all-round stable road performance, adapt to long-term heavy load, high-frequency traffic and complex weather conditions. The pavement shall have excellent high temperature stability, prevent rutting, cradling, pushing and other diseases under high temperature environment in summer; have good low temperature crack resistance, resist low temperature frost, temperature difference impact, and reduce pavement cracking problems. At the same time, it shall meet the standard of high water stability, effectively resist rainwater infiltration, freeze-thaw damage, prevent asphalt spalling, pavement pits, loose and other water damage problems. In addition, the road surface shall have excellent fatigue resistance, can withstand repeated vehicle load rolling, keep the road surface intact and smooth for a long time, and ensure the service life and traffic comfort of the road. 

Standard for pavement structure design 

High-grade asphalt pavement adopts layered composite structure design, which is divided into three layers of asphalt structure: upper layer, middle layer and lower layer, with high-strength base course and stable subgrade, with clear structure hierarchy and uniform stress. The upper surface layer adopts SMA modified asphalt mixture and other high-grade special materials, which mainly focuses on wear resistance, skid resistance, smoothness and noise reduction to ensure driving safety and traffic experience; the middle surface layer is used as the main load-bearing structure, and high-density AC series asphalt mixture is adopted to bear the main vehicle load and improve the structural bearing capacity; the lower layer adopts coarse asphalt concrete to strengthen the overall structural stability and disperse the pavement pressure. The overall structure thickness and layer ratio shall be designed in strict accordance with the national standard, giving consideration to strength, toughness and drainage, so as to meet the long-term heavy-load traffic demand. 

Raw material quality control standards 

All raw materials shall be subject to strict inspection standards, and unqualified materials shall not be put into production and construction. The asphalt raw material shall be selected as compliant road asphalt, and the PG performance test shall be completed for modified asphalt, and the core indicators such as penetration, softening point and ductility shall be strictly controlled to ensure the stability of materials under high temperature and low temperature conditions. Hard, wear-resistant and clean crushed stone materials shall be selected for aggregate. Soil, impurities and weathered stone are strictly prohibited. Aggregate particle size, grading and moisture content shall be strictly controlled. Mineral powder shall be dry, clean and free from caking to ensure its adhesion with asphalt. High-precision measurement standards shall be implemented for all material proportions to ensure the quality of asphalt mixture from the source and prevent pavement quality diseases caused by raw material problems. 

Asphalt mixture production standard 

The mixture must be produced by batch asphalt mixing plant standardization, strictly controlling the production temperature, mixing time and proportion accuracy. Aggregate drying temperature is controlled at 160 - 180℃, asphalt insulation and spraying temperature are controlled in compliance with regulations, so as to prevent aging at too high temperature and insufficient bonding at too low temperature. The material proportion is controlled by high-precision weighing system, the measurement error of aggregate and mineral powder is ≤±0.5%, and the measurement error of asphalt is ≤±0.25%. The mixing time of single pot shall be controlled within 35 - 60 seconds to ensure uniform mixing, no segregation and no agglomeration of the mixture, uniform temperature and stable performance of the finished material, and meet the requirements of high-grade pavement paving construction. 

Durability and Operation Adaptation Standards 

High-grade asphalt roads shall meet the requirements of long-term service life. The service life of conventional design can reach more than 15 years, and there is no large-area damage and aging disease for long-term traffic. At the same time, it is suitable for normal maintenance construction, compatible with RAP recycling maintenance technology, realizing recycling of old pavement milling materials and reducing maintenance costs. The pavement structure adapts to complex working conditions such as plateau and mountainous areas, large temperature difference, strong wind and heavy rain. Through standardized operation and maintenance control, it can effectively reduce fuel energy consumption, reduce equipment failure and pavement diseases, and ensure long-term stable, safe and efficient road traffic.