3D-MC: Differential Compaction Value

  • Differential compaction incorporates a value that the material will compress or compact when rolled
  • Example: a 2" mat is needed and the material compacts at 1/4" per 1 inch. 
  • The compaction coefficiant would be 25%
  • 2.5" would be placed to achieve 2" after compaction
  • The percentage needs to be applied regardless of the material thickness to get uniform compaction without waves
  • Thus 2.5" will be placed for 2" rolled
  • 3.75" for 3" rolled
  • The actual compaction value can be obtained from the plant manager or paving forman
  • This will be entered into RDMC by selecting the <Screed> option under the <Control> tab in the main menu
  • Followed by selecting <Diff. Compaction %>
  • Enter the proper compaction value into the field
  • An incorrect value will result in applying too much or too little material 
  • Select <OK> to confirm
  • The proper amout of material will now be placed for a smoother rolled surface
  • This is a critical when variable depth paving