AASHTO T 209: Effect of Agitation Equipment Type on Theoretical Maximum Specific Gravity Values

This digest summarizes key findings of research conducted in NCHRP Project 10-87(01), "Precision Statements for AASHTO Standard Methods of Test." The digest is an abridgement of the full final report. The goal of the research was to evaluate the effect of using various devices and methods on measured values of the theoretical maximum specific gravity (G sub mm) of hot mix asphalt. The variables examined included agitation and device type, vibration intensity of mechanical shaking tables, order of placing water and mixture in vacuum container, and duration of the vacuum/agitation process.