# Purity

Asphalt cement, as used for HMA paving, should consist of almost pure bitumen. Impurities are not active cementing constituents and may be detrimental to asphalt cement performance.

- Canonical URL: https://pavementinteractive.org/reference-desk/materials/asphalt/purity/
- Last updated: 2026-11-01
- Review: reviewed by licensed professional engineers on the previous Pavement Interactive site, where reviewers were not recorded by name
- Standards: AASHTO T 110, AASHTO T 44, AASHTO T 55, ASTM D1461, ASTM D2042, ASTM D95

[Asphalt cement](https://pavementinteractive.org/glossary/asphalt-cement/), as used for HMA paving, should consist of almost pure bitumen. Impurities are not active cementing constituents and may be detrimental to asphalt cement performance. Mineral impurities can be quantified by dissolving a sample of asphalt cement in trichloroethylene or 1,1,1 trichloroethane through a filter mat. Anything remaining on the mat is considered an impurity. Water impurities are quantified through distillation.

## Related Tests

- AASHTO T 44 and ASTM D 2042: Solubility of Bituminous Materials
- AASHTO T 55 and ASTM D 95: Water in Petroleum Products and Bituminous Materials by Distillation
- AASHTO T 110 and ASTM D 1461: Moisture or Volatile Distillates in Bituminous Paving Mixtures