Base stabilization for new construction is similar to Cold Central Plant Recycling and for reconstruction is similar to FDR. Before creating a specification for your base stabilization project, review the ARRA recommended guidelines for resources in design, testing, quality control, measurement and payment procedures for your project. There are many factors to consider after reviewing the ARRA guidelines, and your project may need slight adjustments to meet the localized conditions of your project.
Base stabilization for new construction is similar to Cold Central Plant Recycling and for reconstruction is similar to FDR. ARRA best practice guidelines for construction for CCPR and FDR are contained in CR102, FDR101, FDR102 and FDR103. ARRA recommended quality control checks for FDR are contained in FDR301 and FDR302. The ARRA guideline may be used to help develop specification guideline for base stabilization. As General rules of thumb, follow the below points and recommendations:
Verify placement width and depth of base stabilized layer
Check the application rate of bituminous recycling agent by evaluating the mass of recycled material against the volume of recycling agent used for a single tanker.
For foamed asphalt check the temperature of the asphalt before connecting a tanker to the recycling unit or mixer.
For foamed asphalt, verify the expansion ratio and half-life using the test nozzle on the recycling unit or mixer.
Verify application rate of dry additives either volumetrically or by using a standard “canvas patch” test, or similar procedure.
Verify application of additives applied by slurry using the consumption of additive (and water) obtained from the computer that controls the slurry mixing unit.
verify compaction moisture content.
Determine percent compaction by comparing the in-place density to the target density established in the control strip. If the uniformity of the mixture changes significantly re-establish the target density.
Check surface tolerance with a 10-foot (3-m) straight edge utilizing a wedge ruler that can slide between the pavement/straight edge interface to accurately measure the gap.
Lime-Treated Soil Construction Manual, Lime Stabilization & Lime Modification. Bulletin 326, National Lime Association, January 2004.
Soil Stabilization and Pavement Recycling with Self-Cementing Coal Fly Ash. American Coal Ash Association Educational Foundation, January 2008.
Guide to Cement-Treated Base (CTB). EB236.01, Portland Cement Association.
Soil-Cement Construction Handbook. EB003.10, Portland Cement Association.