Highways are complex, layered systems designed to endure millions of vehicle loads.
1. Soil Preparation
- Unstable Soil Removal:
Replaced with compacted gravel. - Hidden Drainage:
Sloped gravel layers and perforated pipes prevent water damage.
2. Structural Layers (Strength Pyramid)
| Layer | Thickness | Purpose | Material |
|---|---|---|---|
| Subgrade | 30-50 cm | Load Distribution | Compacted Gravel |
| Base Course | 20-30 cm | Crack Prevention | Cement-Treated Aggregate |
| Binder Asphalt | 10-15 cm | Shock Absorption | Coarse Asphalt |
| Wearing Course | 5-10 cm | Surface Durability | Fine Asphalt |
3. Advanced Techniques
- Rubber-Modified Asphalt:
Recycled tires increase flexibility. - Embedded Sensors:
Monitor stress and wear in real time.
Conclusion
A well-built highway lasts 20+ years under heavy traffic, with 40% lower maintenance costs using modern materials.