AASHTO T 331-21 PDF Download

AASHTO T 331-21 is a standard that outlines the procedure for determining the bulk specific gravity (Gmb) and density of compacted asphalt mixtures using the automatic vacuum sealing method. This method is suitable for samples of hot mix asphalt (HMA) mixtures that contain open or interconnecting voids and absorb more than 2.0 percent of water by volume.

The purpose of this standard is to provide a method for accurately measuring the bulk specific gravity of compacted HMA, which is an important parameter for calculating the unit mass of the mixture. The automatic vacuum sealing method is used to ensure the accuracy and reliability of the measurements.

It is important to note that although this method is similar to ASTM D 6752/D 6752M-11, there may be slight differences between the two standards. Therefore, it is necessary to use AASHTO T 331-21 for compliance with AASHTO specifications and requirements.