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ASTM D6035/D6035M-19
Standard Test Methods for Determining the Effect of Freeze-Thaw on Hydraulic Conductivity of Compacted or Intact Soil Specimens Using a Flexible Wall Permeameter
Přeložit název
NORMA vydána dne 1.11.2019
Informace o normě:
Označení normy: ASTM D6035/D6035M-19
Datum vydání normy: 1.11.2019
Kód zboží: NS-977936
Počet stran: 5
Přibližná hmotnost: 15 g (0.03 liber)
Země: Americká technická norma
Kategorie: Technické normy ASTM
Kategorie - podobné normy:
Anotace textu normy ASTM D6035/D6035M-19 :
Keywords:
coefficient of permeability, cover, freeze-thaw, hydraulic conductivity, liner, permeameter ,, ICS Number Code 13.080.20 (Physical properties of soil)
Doplňující informace
| Significance and Use | ||||||||||||||||
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4.1 This test method identifies the changes in hydraulic conductivity as a result of freeze-thaw on natural soils only. 4.2 It is the user's responsibility when using this test method to determine the appropriate water content of the laboratory-compacted specimens (that is, dry, wet, or at optimum water content) (Note 2). Note 2: It is common practice to construct clay liners and
covers at optimum or greater than optimum water content. Specimens
compacted dry of optimum water content typically do not contain
larger pore sizes as a result of freeze-thaw because the effects of
freeze-thaw are minimized by the lack of water in the sample.
Therefore, the effect of freeze-thaw on the hydraulic conductivity
is minimal, or the hydraulic conductivity may increase
slightly.4.3 The requestor must provide
information regarding the effective stresses to be applied during
testing, especially for determining the final hydraulic
conductivity. Using high effective stresses (that is, 35 kPa [5
psi] as allowed by Test Method D5084) can decrease an already increased
hydraulic conductivity resulting in lower final hydraulic
conductivity values. The long-term effect of freeze-thaw on the
hydraulic conductivity of compacted soils is unknown. The increased
hydraulic conductivity caused by freeze-thaw may be temporary. For
example, the overburden pressure imparted by the waste placed on a
soil liner in a landfill after being subjected to freeze-thaw may
reduce the size of the cracks and pores that cause the increase in
hydraulic conductivity. It is not known if the pressure would
overcome the macroscopically increased hydraulic conductivity
sufficiently to return the soil to its original hydraulic
conductivity (prior to freeze-thaw). For cases such as landfill
covers, where the overburden pressure is low, the increase in
hydraulic conductivity due to freeze-thaw will likely be permanent.
Thus, the requestor must take the application of the test method
into account when establishing the effective stress.
4.4 The specimen(s) shall be frozen to −15°C [5°F] unless the requestor specifically dictates otherwise. It has been documented by Othman, et al3 that the initial (that is, 0 to −15°C [32°F to 5°F]) freezing condition causes the most significant effects in hydraulic conductivity. Freezing rate and ultimate temperature should mimic the field conditions. It has been shown that superfreezing (that is, freezing the specimen at very cold temperatures and very short time periods) produces erroneous results. 4.5 The thawed specimen temperature and thaw rate shall mimic field conditions. Thawing specimens in an oven (that is, overheating) will produce erroneous results. 4.6 According to Othman, et alNote 3: 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. |
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| 1. Scope | ||||||||||||||||
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1.1 These test methods cover laboratory measurement of the effect of freeze-thaw on the hydraulic conductivity of compacted or intact soil specimens using Test Method D5084 and a flexible wall permeameter to determine hydraulic conductivity. These test methods do not provide steps to perform sampling of, or testing of, in situ soils that have already been subjected to freeze-thaw conditions. Test Method A uses a specimen for each hydraulic conductivity determination that is subjected to freeze/thaw while Test Method B uses one specimen for the entire test method (that is, the same specimen is used for each hydraulic conductivity). 1.2 These test methods may be used with intact specimens (block or thin-walled) or laboratory compacted specimens and shall be used for soils that have an initial hydraulic conductivity less than or equal to 1E-5 m/s [3.94 E-4 in./s] (1E-3 cm/s) (Note 1). Note 1: The maximum initial hydraulic conductivity is given as
1 E-5 m/s [3.94 E-4 in./s]. This should also apply to the final
hydraulic conductivity. It is expected that if the initial
hydraulic conductivity is 1 E-5 m/s (3.94 E-4 in./s), then the
final hydraulic conductivity will not change (increase)
significantly (that is, greater than 1 E-5 m/s) (3.94 E-4
in./s).
1.3 Soil specimens tested using this test method can be subjected to three-dimensional freeze-thaw (herein referred to as 3-d) or one-dimensional freeze-thaw (herein referred to as 1-d). (For a discussion of one-dimensional freezing versus three-dimensional freezing, refer to Zimmie and LaPlante or Othman, et al.1.4 Soil specimens tested using this test method can be tested in a closed system (that is, no access to an external supply of water during freezing) or an open system. 1.5 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026. 1.5.1 The procedures used to specify how data are collected/recorded and calculated in the standard are regarded as the industry standard. In addition, they are representative of the significant digits that generally should be retained. The procedures used do not consider material variation, purpose for obtaining the data, special purpose studies, or any considerations for the user’s objectives; and it is common practice to increase or reduce significant digits of reported data to be commensurate with these considerations. It is beyond the scope of the test methods ro consider significant digits used in analysis methods for engineering data. 1.6 Units—The values stated in SI units or inch-pound units (presented in brackets) are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard. Reporting of test results in units other than SI shall not be regarded as nonconformance with this test method. 1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.8 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. |
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| 2. Referenced Documents | ||||||||||||||||
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