Understanding asphalt density for accurate project calculations and material estimation
The unit weight of asphalt (also called density) refers to the mass of asphalt per unit volume. This is a critical measurement for construction projects, as it determines how much material is needed and affects cost calculations, transportation requirements, and structural performance.
The typical unit weight of hot mix asphalt varies depending on the specific mix design, but generally falls within these ranges:
| Measurement System | Unit Weight Value |
|---|---|
| Metric | 2,200 - 2,400 kg/m³ (average: 2,322 kg/m³) |
| Imperial | 140 - 150 lb/ft³ (average: 145 lb/ft³) |
| Tons per cubic meter | 2.2 - 2.4 tons/m³ |
| Tons per cubic yard | 1.8 - 2.0 tons/yd³ |
Industry Standard:
For most asphalt calculation purposes, the standard density value used is 2,322 kg/m³ (145 lb/ft³).
Several factors can influence the unit weight of asphalt:
| Asphalt Mix Type | Typical Density (kg/m³) | Typical Density (lb/ft³) |
|---|---|---|
| Dense-Graded Mix | 2,300 - 2,400 | 143 - 150 |
| Open-Graded Friction Course | 1,900 - 2,100 | 118 - 131 |
| Stone Matrix Asphalt (SMA) | 2,350 - 2,450 | 147 - 153 |
| Cold Mix Asphalt | 2,100 - 2,300 | 131 - 143 |