The Marshall System is widely used for design and control of bituminous paving mixtures. The resistance to plastic flow of compacted cylindrical specimens is measured in terms of maximum load before fracture occurs. Standard 4" (102mm) diameter specimens are suitable for up to 1" (25.4mm) maximum aggregate size.
Four-inch specimens may be compacted with a 10 lb (4.54kg) hammer having 3-7/8" (98mm) circular face and 18" (457mm) free fall.
The ACM-MS-12 has a special guide to hold the handle of the hammer perpendicular to the base of the mold assembly during compaction. Overall dimensions of manual sets are 12x12x64" (305x305x1626mm). Manual compaction sets include Hammer Assembly, Compaction Mold assembly, and Mold Holder.
Automatic Mechanical compactors have a surcharge weight applied to the hammer foot during compaction. The weight is automatically lifted and released the exact number of hammer blows preset on the digital counter. Multiple automatic units permit duplicate compacting of check specimens under exact temperature conditions. They are also useful for mix design labs or labs with many test to run. Compaction Mold Assemblies, mold holders, hammers, counters, pedestals, and belt guards are provided with all mechanical compactors. Mechanical units are approximately 20x66"LxH (508x1676mm) overall, and approx. width is 12" (305mm), 17" (432mm), and 20" (508mm) for single, double and triple units. |
