1、Designation: D 4404 84 (Reapproved 2004)Standard Test Method forDetermination of Pore Volume and Pore Volume Distributionof Soil and Rock by Mercury Intrusion Porosimetry1This standard is issued under the fixed designation D 4404; the number immediately following the designation indicates the year o
2、foriginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of the porevolu
3、me and the pore volume distributions of soil and rock bythe mercury intrusion porosimetry method. The range ofapparent diameters of pores for which this test method isapplicable is fixed by the operant pressure range of the testinginstrument. This range is typically between apparent poreentrance dia
4、meters of about 100 m and 2.5 nm (0.0025 m).Larger pores must be measured by another method.1.2 Mercury intrusion porosimetry is useful only for mea-suring pores open to the outside of a soil or rock fragment;mercury intrusion porosimetry will not give the volume of anypores completely enclosed by s
5、urrounding solids. This testmethod will give only the volume of intrudable pores that havean apparent diameter corresponding to a pressure within thepressurizing range of the testing instrument.1.3 The intrusion process proceeds from the outside of afragment toward its center. Comparatively large in
6、terior porescan exist that have smaller pores as the only means of access.Mercury intrusion porosimetry will incorrectly register theentire volume of these “ink-bottle” pores as having theapparent diameter of the smaller access pores. In a test sample,inter-fragment pores can exist in addition to in
7、tra-fragmentpores (see Section 3 for definitions). The inter-fragment poreswill vary in size and volume depending on the size and shapeof the soil or rock fragments and on the manner in which thefragments are packed together. It is possible that some inter-fragment pores can have the same apparent d
8、iameter as someintra-fragment pores. When this occurs, this test method cannotdistinguish between them. Thus, the test method yields anintruded pore volume distribution that is in part dependentupon the packing of multifragment samples. However, mostsoils and rocks have intra-fragment pores much sma
9、ller thanthe inter-fragment pores. This situation leads to a bi-modalpore size distribution and the distinction between the twoclasses of pores can then be made (see Fig. 1 and Fig. 2).1.4 Mercury intrusion may involve the application of highpressures to the sample. This may result in a temporary, o
10、rpermanent, or temporary and permanent alteration in the poregeometry. Generally, soils and rocks are composed of com-paratively strong solids and are less subject to these alterationsthan certain other materials. However, the possibility remainsthat the use of this test method may alter the natural
11、 porevolume distribution that is being measured.1.5 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to consult andestablish appropriate safety and health practices and deter-mine the applicabil
12、ity of regulatory limitations prior to use.For specific precaution statements, see Section 8.2. Referenced Documents2.1 ASTM Standards:2C 699 Method for Chemical, Mass Spectrometric, andSpectrochemical Analysis of, and Physical Tests on, Be-ryllium Oxide Powder33. Terminology3.1 Definitions:3.1.1 ap
13、parent pore diameterthe diameter of a pore that isassumed to be cylindrical and that is intruded at a pressure, P,given by the equation in 4.1.3.1.2 inter-fragment poresthose pores between fragmentswhen they are packed together and that are intruded during thetest.3.1.3 intra-fragment poresthose por
14、es lying within theexterior outlines of the individual soil and rock fragments.3.1.4 intruded pore volumethe corrected volume of mer-cury intruded during the test.4. Summary of Test Method4.1 When a liquid does not wet a porous solid, it will notenter the pores in the solid by capillary action. The
15、non-wetting1This test method is under the jurisdiction of ASTM Committee D18 on Soil andRock and is the direct responsibility of Subcommittee D18.06 on Physical-ChemicalInteractions of Soil and Rock.Current edition approved July 1, 2004. Published July 2004. Originally approvedin 1984. Last previous
16、 edition approved in 1998 as D 4404 - 84 (1998)e1.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Withdrawn.
17、1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.liquid (mercury in this test method) can be forced into the poresby the application of external pressure. The size of the poresthat are intruded is inversely proportional to the applied
18、pressure. When a cylindrical pore model is assumed, therelationship between pressure and size is given as follows:d 524gcosu!/P (1)where:d = apparent pore diameter being intruded,g = surface tension of the mercury,u = contact angle between the mercury and the pore wall,andP = absolute pressure causi
19、ng the intrusion.Any set of convenient and compatible units may be used.4.2 The volume of the intruded pores is determined bymeasuring the volume of mercury forced into them at variouspressures. A single determination involves increasing thepressure, either continuously or step-wise, and recording t
20、hemeasured intruded volume at various pressures.5. Significance and Use5.1 This test method is intended for use in determining thevolume and the volume distribution of pores in soil and rockwith respect to the apparent diameter of the entrances of thepores. In general, both the size and volume of th
21、e pores affectsFIG. 1 Example of Cumulative Pore Volume Distribution PlotFIG. 2 Example of Differential Pore Volume Distribution PlotD 4404 84 (2004)2the soil or rock performance. Thus, the pore volume distribu-tion is useful in understanding soil and rock performance andin identifying a material th
22、at can be expected to perform in aparticular manner (1, 2).46. Apparatus6.1 Mercury Intrusion PorosimeterThis shall be equippedwith a sample holder capable of containing one or several soilor rock fragments. This sample holder is frequently called apenetrometer. The porosimeter shall have a means of
23、 surround-ing the test specimen with mercury at a low pressure, apressure generator to cause intrusion, pressure transducers,capable of measuring the intruding pressure with an accuracyof at least 61 % throughout the range of pressures over whichthe pores of interest are being intruded, and a means
24、ofmeasuring intruded mercury volumes to an accuracy of at least61mm3(6103cm3).6.2 Vacuum Pump, if not part of the porosimeter, to evacuatethe sample holder.6.3 Analytical Balance, with an accuracy of at least 6107kg (60.1 mg).7. Reagent7.1 Triple-Distilled Mercury.8. Safety Precautions8.1 Mercury is
25、 a hazardous substance that can cause illnessand death. Store mercury in closed containers to control itsevaporation and use only in well-ventilated rooms. Mercurycan also be absorbed through the skin, so avoid direct contact.Wash hands immediately after any operation involving mer-cury; the use of
26、gloves is advocated. Exercise extreme care toavoid spilling mercury. Clean up any spills immediately usingprocedures recommended explicitly for mercury. Handle in-truded samples with great care and dispose of in a safe andenvironmentally acceptable manner immediately after comple-tion of the test.9.
27、 Sampling, Test Specimens, and Test Units9.1 The material from which the test sample is drawn shallbe representative of the soil or rock. The test sample shall be aslarge as practicable considering the test apparatus.NOTE 1Sample size is limited by the pore-measuring capacity of thepenetrometer, whi
28、ch is currently (1984) slightly more than 1 cm3. Thesmall sample size may prevent the measurement of porosity representedby relatively large cracks and fissures in the material. Judgement isrequired in the application of these measurements to the characterizationof the soil or rock masses.10. Condit
29、ioning10.1 The ideal preconditioning for the test specimen is anoutgassing or drying procedure that removes all foreign sub-stances from the pores and pore walls of the soil or rock anddoes not alter the soil or rock in any way. If possible, theappropriate combination of temperature and pressure and
30、 therequired time of conditioning shall be experimentally deter-mined for the specific soil or rock under test. This outgassingor drying technique shall then be the one specified and used.10.2 Where the procedure described in 10.1 is not practical,rock or coarse-grained soil without fines shall be o
31、utgassed ina vacuum at least 1.3 Pa (10 mHg) and at a temperature of150C for at least 24 h. Soil containing any plastic finesrequires special drying procedures to avoid alteration of porestructure. Freeze drying has been successfully employed (3, 4)and is a simple procedure. Critical region drying m
32、ay also beused (5), but is more complex and expensive than freezedrying.11. Procedure11.1 Outgas or dry the test specimen in accordance with10.1 or 10.2.11.2 Weigh the outgassed or dried specimen and record thisweight.11.3 Place the outgassed or dried material in the penetrom-eter.NOTE 2When perform
33、ing the operation described in 11.2 and 11.3,the outgassed or dried material is exposed to the laboratory atmosphereand can readsorb vapors. Thus, this operation should be carried out asrapidly as possible.11.4 Place the penetrometer containing the sample in theappropriate chamber of the porosimeter
34、, following the manu-facturers instructions, and evacuate to a pressure of at least 1.3Pa (10 mHg).11.5 Fill the penetrometer with mercury, in accordance withthe manufacturers instructions, by pressurizing to some suit-ably low pressure.NOTE 3The pressure required to fill the penetrometer with mercu
35、ry isalso capable of intruding sufficiently large pores of both the inter- andintra-fragment classes. Thus, the process can intrude some pores and thevolume distribution of these pores cannot subsequently be determined.This fact should be recognized, and where possible, a filling pressureshould be s
36、elected that will not intrude pores in the diameter range ofinterest.11.6 Place the filled penetrometer in the pressure vessel ofthe porosimeter and prepare the instrument for pressurizationand intrusion readings in accordance with the manufacturersinstructions.11.7 Raise the pressure, either contin
37、uously or incremen-tally, and record both the absolute pressure and the volume ofintruded mercury until the maximum pressure of interest isreached.NOTE 4When raising the pressure incrementally, the pressure shall bemaintained during the pause and not allowed to decrease.NOTE 5When testing some mater
38、ials, the time required to achieveintrusion equilibrium will not be the same at all pressures. Often theequilibrium time is appreciably longer at pressures that cause an abruptand large increase in intruded volume. Failure to record the equilibriumintrusion may result in some of the pore volume bein
39、g incorrectly assignedto smaller pore diameters. The extent to which this may be a problem canbe assessed by conducting two tests, each at a different pressure increaserate, and comparing the results.NOTE 6Use of the equation in 4.1 requires the absolute pressure, P.With some instruments it may not
40、be possible to read the absolute pressuredirectly. In this case, the gage pressure shall be recorded at each step, andthe absolute pressures subsequently calculated.4The boldface numbers in parentheses refer to the list of references appended tothis standard.D 4404 84 (2004)3NOTE 7The choice of pres
41、sure intervals at which data are to berecorded is left to the judgment of the operator. Normally, at least 10 to 15intervals will be required to adequately define the pore volume distribu-tion. In selecting these pressure intervals, a rough idea of the expecteddistribution is helpful, since the pres
42、sure interval can be larger in regionswhere little or no intrusion occurs and should be smaller in regions wherea large volume of intrusion is expected. It is not necessary to continue theprocess up to the maximum pressurizing capability of the instrument if allof the pores of interest in a particul
43、ar test specimen have been intruded ata lesser pressure.11.8 Upon completion of the pressuring cycle, reduce thepressure and disassemble and clean the instrument in accor-dance with the manufacturers instructions.12. Blank Test for Corrections12.1 An intrusion test on a nonporous sample is required
44、toobtain values to use in correcting intrusion data for compress-ibilities and temperature changes.12.2 Select a nonporous material that has approximately thesame compressibility and bulk volume as the soil or rocksample that is to be tested.12.3 Test the nonporous sample in exactly the same mannera
45、s outlined in Section 11. Raise the pressure in the same stepsused for the soil or rock tests to ensure that temperaturechanges due to pressuring are the same.12.4 Results of the blank run are a series of measuredvolume changes that can also be expected to occur along withactual intrusion in a test
46、on a material. Such blank run resultsare used to correct the intruded volumes as discussed in 13.3.2.12.5 Compressibilities of the various components in thesystem augment the measured intrusion values while thepressure-induced heating and consequent expansion of thesystem reduces the measured volume
47、s. In a particular instru-ment, one of these effects will be dominant. Therefore, resultsof the blank test will be either an apparent intrusion (compress-ibility dominant) or an expulsion of mercury (heating domi-nant).12.5.1 If results show apparent intrusion, they are to besubtracted from the valu
48、es measured in the test on the soil orrock.12.5.2 If the blank results show a mercury expulsion, theyare to be added to the volumes in a test on the soil or rock.13. Calculation13.1 Intruding pressures must be expressed as absolutepressures before they can be used to compute the correspond-ing pore
49、diameters. If the recorded values are gage pressures,they should be converted to absolute pressures in accordancewith the manufacturers instructions. If the instrument readsdirectly in absolute pressure, omit this step.13.2 Absolute pressures are converted to apparent intrudedpore diameters using the equation in 4.1. This step requires thatsurface tension and contact angle be known.13.2.1 Where triple-distilled mercury is used, the surfacetension can generally be relied upon to be that reported inhandbooks, that is, 0.484 N/m (484 d/cm) at 25C. Smalldeviatio
