Lecture Notes: Introduction to Superpave System

Overview of Asphalt Pavements

Asphalt pavements are known for their smooth ride and durability.
The Superpave system is a new set of tools and techniques for designing more durable asphalt pavements.
Superpave stands for Superior Performing Asphalt Pavements.

Performance-Based Asphalt Binder Specification
- Binders are classified into performance grades (PG) based on climate and pavement temperature.
- Two key numbers in PG ratings: high and low pavement temperatures.
- Example: PG 64-22 withstands temperatures from 64°C to -22°C.
- Weather database included for selecting appropriate binders based on location.
- Performance-based specification ensures binders will perform as expected.
Volumetric Mix Design and Analysis
- Mixes are based on volumetric properties like air voids and voids in the mineral aggregate.
- Aggregate selection is based on consensus properties such as angularity and clay content.
- Source properties like toughness and soundness are also considered.
Improved Laboratory Compaction Method
- The Superpave Gyratory Compactor (SGC) is used for compaction.
- It simulates field conditions more accurately and gives reproducible results.
- The specimen is compacted by rotating in a mold under pressure.

Aggregates: Determine based on consensus and source properties.
Design Aggregate Structure: Develop trial blends and determine their volumetric properties.
Design Asphalt Binder Content: Find optimal binder content for 4% air voids using the SGC.

Includes voids in the mineral aggregate (VMA), voids filled with asphalt (VFA), and air voids.
Control of these properties ensures expected pavement performance.

Nationwide adoption expected by 1997 for binder specification and 2004 for mix design procedures.
Transition coordinated by the Federal Highway Administration and other organizations.
Training and technical assistance available from various sources.

Superpave is the future of asphalt pavement technology, offering tools for designing longer-lasting pavements.
Ready for implementation, providing benefits to highway agencies and paving contractors.