GUIDELINES
FOR RECERTIFICATION OF STOCKPILES
It may become necessary to re-certify a stockpile for
gradation that was previously certified. Below are guidelines for deciding when
recertification is needed and when it may not be necessary.
When it may be necessary:
- Stockpiles that appear to be contaminated.
- Stockpiles from ledges that have a history of generating
minus No. 200 fines over time.
- HMA coarse aggregate produced from low quality ledges or
ledges that incorporate a blend of high and low quality beds may need to
be recertified if held over the winter.
- Class A made from ledges with abrasion over 40 and
C-freeze over 5 may need to be re-sampled if held over the winter.
When it may not be necessary:
- Stockpiles of porous backfill, concrete sand, or washed
products with low alumina/A-freeze specifications probably will have no
“breakdown” over a winter due to freeze-thaw damage.
- In general, stockpiles with low alumina/A-freeze washed
products produced on the coarse side of the gradation specification where
the minus No. 200 mesh sieve was low the previous year.
- Stockpile recertification is not necessary for Class A
produced with a coarse gradation from most ledges.