Unit Weight of Asphalt

Reference

Drawings show areas and thicknesses but the plant sells tonnes, and the unit weight of compacted mix is the bridge between them.

2400 kg per cubic meter, compacted
Compacted hot mix asphalt2300 to 2450 kg/m3
In force units23 to 24 kN per cubic meter
US customary, compacted140 to 150 lb per cubic foot
Loose mix in the truck1900 to 2000 kg/m3
Millings, loose1600 to 1900 kg/m3
Field rule24 kg per square meter per 10 mm compacted

Notes for design and site

The spread comes from two places: the aggregate and the air. Mix designs target roughly 92 to 96 percent of maximum theoretical density after rolling, and the same mix at the two ends of that band differs by about 4 percent in unit weight. Heavier aggregates push a dense graded mix toward 2450 kg/m3, absorptive or lighter stone pulls it under 2350.

Order using the compacted number, because the roller does not manufacture material. A 100 m street, 7.4 m wide, paved 50 mm thick is 37 cubic meters compacted, which at 2.4 tonnes per cubic meter is about 89 tonnes of mix. The same arithmetic in reverse catches problems: divide delivered tonnes by area and unit weight and you get the average placed thickness, which is how a yield check exposes a thin lift before any cores are cut.

Loose material is a different commodity. Mix in the truck runs around 1.9 to 2.0 tonnes per cubic meter and millings looser still at 1.6 to 1.9, so a box measured in loose volume always holds fewer tonnes than the compacted math suggests.

Related Calculators and Reference