AASHTO R 90:2018 Standard Practice for Sampling Aggregate Products.
5.8. Sampling from Stockpile for Coarcc’ Aggregate anti Mixtures of Coarse and Fine Aggregate
5.8.1. Sampling from a Flat Sur/Oce created by a Loader:
5.8.1 .1. Direct the loader operator to enter the stockpile with the bucket at least 0.3 rn (I fi) above ground level without contaminating the stockpile. Discard the first bucketful. Have the loader re-enter the stockpile, obtain a full loader bucket of the material, and tilt the bucket back and up. Form a small sampling pile at the base of the stockpile by gently rolling the material out of the bucket with the bucket just high enough to permit free flow of the material. Repeat as necessary.
5.8.1 .5. Create a f1at surface by having the loader back drag the small pile.
5.8.1 .6. Obtain increments from at least three randomly selected locations on the flat surface at least 1 ft (300 mm) from the edge. Fully insert the shovel, exclude the underlying material, roll back the shovel, and lift the material slowly out of thc pile to avoid material rolling off the shovel. Combine the increments to form a sample.
5.8.2. Sainpling,froin a Horizontal Sur/iice on the Stockpile Face: Create horizontal surfaces with vertical faces in the top, middle, and bottom third of the stockpile with a shovel, or with a loader if one is available. Shove a flat board against the vertical face behind sampling location to prevent sloughing. Discard sloughcd material to create the horizontal surface. Obtain sample from the horizontal surface as close as possible to the intersection of the horizontal and vertical faces. Obtain at least one increment of equal size from each of the top, middle, and bottom thirds of the pile. Combine the increments to form a single sample.
5.9. Sampling from a Stockpile for Fine Aggregate (Alternate Tube Method,.):
5.9.1. Remove the outer layer of material.
5.9.2. Using a sampling tube, obtain incrcrncnts of equal size from a minimum of five random locations on the pile.
5.9.3. Combine the increments to form a single sample.AASHTO R 90 pdf download.