STANDARD PRACTICE FOR SAMPLING AGGREGATES

 II. STANDARD PRACTICE (ASTM D 75)

FOR SAMPLING AGGREGATES

1. Scope:

This practice covers sampling of coarse and fine aggregates for:

- Preliminary investigation of the potential source of supply

- Control of the product at the source of supply

- Control of the operations at the site of use and

- Acceptance or rejection of the materials

2. Significance and Use :

Sampling is equally as important as the testing, and the sampler shall use every precaution to obtain

samples that will show the nature and condition of the materials which they represent. Samples for

tests to be used in acceptance or rejection decisions by the purchaser are obtained by the purchaser or his authorised representative.

3. Securing Samples:

Where practicable, samples to be tested for quality shall be obtained from the finished product. The

seller shall approve suitable equipment needed for proper inspection and sampling.

4. Procedure:

4.1 Sampling from Stockpiles

Avoid sampling coarse aggregate or mixed coarse and fine aggregate from stockpiles whenever

possible, particularly when the sampling is done for the purpose of determining aggregate properties

that may be dependent upon the grading of the sample. If circumstances make it necessary to obtain

samples from a stockpile of coarse aggregate or a stockpile of combined coarse and fine aggregate,

design a sampling plan for the specific case under consideration. This approach will allow the

sampling agency to use a sampling plan that will give confidence in results obtained therefrom that

is agreed upon by all parties concerned to be acceptable for the particular situation. The sampling

plan shall define the number of samples necessary to represent lots and sub-lots of specific sizes. For

general guidance in sampling from stockpiles, see the Appendix-I.

4.2 Sampling from Roadway (Bases and Sub-bases)

Sample by a random method, from the construction site. Obtain at least three approximately equal

increments (quantity), selected at random from the unit being sampled, and combine to form a field

sample whose mass equals or exceeds the minimum recommended in table 3.1. Take all

increments (quantity) from the roadway for the full depth of the material, taking care to exclude

any underlying material. Clearly mark the specific are as from which each increment is to be

removed; a metal template placed over the area is a definite aid in securing approximately equal

increment weights (quantity).

Sampling Aggregates,Standard Practice for Sampling Aggregates,Standard Practice for Sampling Aggregates D75/D75M,

5. Number and Masses of Field Samples:

5.1 The number of field samples required (obtained by the methods described earlier), depends on

the variation in the properties to be measured. The number of field samples from the production

Should be sufficient to give the desired confidence in test results.

5.2 The masses must be predicated on the type and number of tests to which the material is to be

Subjected and sufficient material obtained to provide for the proper execution of these tests. Standard acceptance and control tests are covered by ASTM standards and specify the portion of the field Sample required for each specific test. Generally speaking, the amounts specified in Table will

Provide adequate material for routine grading and quality analysis. Extract test portions from the

field sample as required by the specific test methods.

6. Shipping Samples:

6.1 transport aggregates in bags or other containers so constructed as to preclude loss or contamination of any part of the sample, or damage to the contents from mishandling during

shipment.

6.2 Shipping containers for aggregate samples shall have suitable individual identification attached

and enclosed so that field reporting, laboratory logging, and test reporting may be facilitated.