Sampling is of equal importance to testing and a man collecting samples should use every precaution to obtain samples that will show the true nature and condition of the materials which they represent.
Aggregate Sampling from Stockpile
Using a front end-loader, dig into the stockpile and set aside small pile of 10 to 15 ton of material.
When forming the small pile, the loader bucket must be kept as low as possible and roll the material from the bucket rather than dumping the material. This technique is applied in order to reduce segregation of aggregate.
Each additional bucket load of material is obtained and placed uniformly over the preceding one in the same manner as described above.
Thoroughly mix the small pile. Using the loader bucket, go the end of the oblong pile and roll the material over. Keeping the loader bucket as low as possible, push the bucket into the material until the front of the bucket passes the midpoint of the original pile. Raise the loader bucket slowly and roll forward thus producing a smooth mixing of the material. Go to the opposite end of the pile and repeat this mixing procedure until the pile mixed uniformly.
The pile is now ready for sampling. Do not strike off the top. The sample is taken at the centre of the volume which is approximately one-third of the height of the pile.
The shovel is inserted full depth horizontally into the material and raised vertically. Continue this process until the required amount of sample is collected.
Fine aggregates are sampled using the same technique used to sample coarse aggregate, except a sampling tube or fire shovel is used instead of large shovel.