Full Depth Reclamation Mix Design

Mix designs are not typically required for FDR using pulverization or mechanical stabilization. Testing typically consists of determining the optimum moisture content and maximum dry density using standard or modified Proctor moisture-density tests for use in compaction quality control.

Mix designs are recommended for all bituminous and cementitious stabilized FDR applications. Engineering judgement may be necessary, and adjustments may be required in the field to modify the design content of the stabilizing agent to obtain optimum field performance. If materials vary along the project, more than one mix design may be required. See ARRA publication FDR201A for mix design procedures with emulsified asphalt and FDR202 for cementitious FDR mix design procedures. Regardless of the stabilizing agent used, FDR mix designs should include the following general procedures:

1. Obtain samples of asphalt pavement, base and underlying materials from the roadway
2. Crush asphalt pavement to generate RAP
3. Combine RAP, base and underlying materials to desired percentages and determine gradation, plasticity index, Ph, sulfates and sand equivalent of combined materials
4. Determine need for and select stabilizing agent and additives, if necessary, based on structural and material requirements
5. Determine maximum dry density and optimum moisture content of combined materials
6. Mix and compact specimens at desired moisture content with varying percentages of stabilizing agent 
7. Cure specimens
8. Test trial mixtures for strength and durability 
9. Establish job mix formula
10. Make adjustments in the field as necessary