Bruce Marshall created a mixture design method in the early 1940's with the following objectives:

• Sufficient asphalt to ensure a durable pavement.
• Sufficient mixture stability to satisfy the demands of traffic without distortion or displacement.
• Sufficient voids in the total compacted mixture to allow for a slight amount of additional compaction under traffic loading without flushing, bleeding, and loss of stability, yet low enough to keep out harmful air and moisture.
• Sufficient workability to permit efficient placement of the mixture without segregation.

The accurate measurement of stability and flow of specimens tested in a load frame is important if consistent and representative results are to be achieved. The load frames and ancillary items have been designed to enable technicians to test specimens quickly and easily with confident recording of results.

Complies with BS, ASTM and AASHTO.

• Both Analogue and Digital displays are available
• Internal limit switch for both directions of travel