Maximum index density, maximum unit weight
The maximum index density/unit weight of a given free-draining soil is determined by placing either oven-dried or wet soil in a mold, applying a 2-lb/in.2 (14-kPa) surcharge (dead weight) to the surface of the soil, and then vertically vibrating the mold, soil and surcharge. Use either an electromagnetic, eccentric, or cam-driven vibrating table having a sinusoid-like time-vertical displacement relationship at a double amplitude of vertical vibration (peak-to-peak) of about 0.013 in. (0.33 mm) for 8 min at 60 Hz or about 0.019 in. (0.48 mm) for 10 min. at 50 Hz. The maximum index density/unit weight is calculated by dividing the oven-dried mass/weight of the densified soil by its volume (average height of densified soil times area of mold).
0.1 ft³ to 0.5 ft³, depending on maximum particle size
Maximum index density, maximum index unit weight, relative density, vibrating table