Asphalt Mixtures

Asphalt mixtures and types from Washington State specifications.

These are the specifications for WSDOT Standard Hveem mixes:

Class A.

This is dense-graded HMA that has at least 90 % of the coarse aggregate having at least one fractured face.

This material is mainly used as a surface course for locations with high traffic levels.

Class B.

Class B is dense-graded HMA with at least 75 percent of the coarse aggregate having at least one fractured face.

This material finds use as a leveling course or surface course. The WSDOT uses this as a "standard" surface course paving mix.

Class D.

This is an open-graded HMA. Typically, these mixes are placed as 0.70 inch thick wearing courses. The material has been used in the state route system, with variable results, as there is evidence that it is susceptible to studded tire wear.

Class E.

This is dense-graded HMA that is mainly intended for use as a base course. It is also a WSDOT "standard" base course paving mix and may be used as a heavy duty mix.

Class F.

This is dense-graded HMA similar to Class B but with a wider gradation specification. This is often used instead of Class A/B where aggregate sources properties cannot meet Class A/B requirements.

Class G.

This is dense-graded HMA for thin lifts, often of 1 inch or less. The nominal maximum aggregate size is about 0.375 inches. The size makes it usable as a hot maintenance sealing agent and as paving for playground, bicycle path and athletic facility pavements.

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