Standard Test Method for Specific Gravity of Soil Solids by Gas Pycnometer

Importancia y uso:

5.1 The specific gravity value is used in many phase relation equations to determine relative volumes of particle, water, and gas mixtures.

5.2 The term soil particle typically refers to a naturally occurring mineral grain that is not readily soluble in water. Therefore, the specific gravity of soils that contain extraneous matter (such as cement, lime, and the like) or water-soluble material (such as salt) must be corrected for the precipitate that forms on the test specimen after drying. If the precipitate has a specific gravity less than the parent soil grains, the uncorrected test result will be too low. If the precipitate has a higher specific gravity, then the uncorrected test value will be too high.

5.3 Heating during drying may diagenetically alter the structure of some clay minerals.3 Therefore caution should be exercised if the mineral composition of a clay test specimen is going to be determined after drying. It is possible to dry the test specimen at a lower temperature. However, the effect on water content4 and hence specific gravity should be investigated. In addition, some materials other than clay may be affected by drying at 110°C, such as gypsum, soils containing organics, fly ash containing residual coal, island sands. Test Method D2216 includes recommendations for drying gypsum using a lower temperature, such as 60°C.

Note 1: The quality of the result produced by this standard is dependent on the competence of the personnel performing it, and the suitability of the equipment and facilities used. Agencies that meet the criteria of Practice D3740 are generally considered capable of competent and objective testing. Users of this standard are cautioned that compliance with Practice D3740 does not in itself ensure reliable results. Reliable results depend on many factors; Practice D3740 provides a means of evaluating some of those factors.

Subcomité:

D18.03

Referida por:

D4018-23, F1815-11R18, D0854-23, E2277-14R19

Volúmen:

04.08

Número ICS:

13.080.10 (Chemical characteristics of soil)

Palabras clave:

desiccant; salinity; soil; specific gravity; water content;