Standard Test Method for Expansion Index of Soils

Importancia y uso:

5.1 The expansion index, EI, value is used by engineers and other professionals as an indicator of the soil’s swelling potential. It may also be used to determine the suitability of a soil to satisfy requirements set by specifying agencies.

5.2 The EI test is not used to duplicate any particular field conditions such as soil density, water content, loading, in-place soil structure, or soil water chemistry. However, consistent test conditions are used in preparation of compacted specimens such that direct correlation of data can be made.

5.3 Based on experience with expansive soils, the recommended qualitative classification of potential expansion in a soil based on EI is provided in Table 1.

5.4 The measurement of the magnitude of one-dimensional wetting-induced swell or collapse (hydrocompression) under different vertical (axial) pressures, as well as the magnitude of swell pressure and the magnitude of free swell, and also the determination of data for stress-induced compression following wetting-induced swell or collapse are covered by Test Methods D4546. The ability to test intact specimens for measuring one-dimensional wetting-induced swell or collapse is also covered in Methods D4546.

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/sampling/inspection/etc. Users of this standard are cautioned that compliance with Practice D3740 does not in itself assure reliable results. Reliable results depend on many factors; Practice D3740 provides a means of evaluating some of those factors.

Subcomité:

D18.05

Volúmen:

04.08

Número ICS:

93.020 (Earth works. Excavations. Foundation construction. Underground works)

Palabras clave:

clays; expansion index; expansive soils; index tests; laboratory tests; soil moisture; swelling soils;