1. What is Effective Asphalt Content?

Effective Asphalt Content (EAC) represents the amount of asphalt binder available for coating aggregate particles and providing durability in Hot Mix Asphalt (HMA) design. It is calculated by subtracting the absorbed asphalt from the total asphalt content.

2. How Does the Formula Work?

The calculator uses the Effective Asphalt Content formula:

Where:

• \( EAC \) — Effective Asphalt Content (%)
• \( Total Asphalt \) — Total asphalt binder content in the mix (%)
• \( Absorbed Asphalt \) — Asphalt absorbed by aggregate particles (%)

Explanation: The formula calculates the actual asphalt available for binding and coating purposes by accounting for the portion absorbed into the aggregate pores.

3. Importance of EAC Calculation

Details: Accurate EAC calculation is crucial for HMA mix design optimization, ensuring proper coating, durability, and performance characteristics of asphalt pavements.

4. Using the Calculator

Tips: Enter total asphalt content and absorbed asphalt as percentages. Both values must be non-negative numbers representing weight percentages in the mix design.

5. Frequently Asked Questions (FAQ)

Q1: What is the typical range for EAC in HMA design?
A: EAC typically ranges from 3.5% to 6.0% depending on aggregate gradation, traffic levels, and environmental conditions.

Q2: How does EAC affect pavement performance?
A: Proper EAC ensures adequate film thickness for durability while preventing issues like rutting, raveling, or moisture damage.

Q3: What factors influence absorbed asphalt content?
A: Aggregate porosity, surface texture, and mineral composition significantly affect the amount of asphalt absorbed.

Q4: How is total asphalt content determined?
A: Total asphalt content is typically determined through extraction tests or batch plant records in mix design.

Q5: Can EAC be negative?
A: No, EAC cannot be negative as absorbed asphalt should not exceed total asphalt content in properly designed mixes.