4137.01 DESCRIPTION.
Asphalt binder shall meet the requirements for the type and grade specified in the contract documents.

4137.02 ASPHALT BINDER.
Asphalt binder prepared from petroleum shall be of the performance grade specified in the contract documents and shall meet the requirements of AASHTO M 320. Determination of performance grade shall be in accordance with AASHTO PP6.

Modification of asphalt binders by addition of acids will not be allowed.