Standard Test Method for Determination of Pore Volume and Pore Volume Distribution of Soil and Rock by Mercury Intrusion Porosimetry

Importancia y uso:

5.1 This test method is intended for use in determining the volume and the volume distribution of pores in soil and rock with respect to the apparent diameter of the entrances of the pores. In general, both the size and volume of the pores affects the performance of soil and rock. Thus, the pore volume distribution is useful in understanding soil and rock performance and in identifying a material that can be expected to perform in a particular manner (1, 2).3

5.2 The intrusion process to determine the volume of a pore proceeds from the outside of a specimen toward its center. Comparatively large interior pores can exist that have smaller outside openings as the only means of access. Mercury intrusion porosimetry will incorrectly register the entire volume of these “ink-bottle” pores as having the apparent diameter of the smaller access pores. In a test specimen, exterior specimen pores can exist in addition to intra-specimen pores (see 3.2 for definitions). The inter-fragment pores will vary in size and volume depending on the size and shape of the soil or rock fragments and on the manner in which the fragments are packed together. It is possible that some exterior specimen pores can have the same apparent diameter as some intra-specimen pores. When this occurs, this test method cannot distinguish between them. Thus, the test method yields an intruded pore volume distribution that is in part dependent upon the packing of multifragment specimens. However, most soils and rocks have intra-fragment pores much smaller than the inter-fragment pores. This situation leads to a bi-modal pore size distribution and the distinction between the two classes of pores can then be made (see Figs. 1 and 2). The intr-fragment pore concentration is shown to the left of the plot; the inter-fragment concentration is to the right.

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:

D18.06

Referida por:

F3510-21, D4520-18, F2150-19, F2902-24, F2450-18

Volúmen:

04.08

Número ICS:

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

Palabras clave:

hydraulic conductivity; mercury intrusion; mercury extrusion; permeability; pore volume distribution; pore volume; pore size; porosimetry; porosity; soil; voids;