Designation D2980 − 17 Standard Test Method for Saturated Density, Moisture Holding Capacity, and Porosity of Saturated Peat Materials1 This standard is issued under the fixed designation D2980; the n[.]
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 Designation: D2980 − 17 Standard Test Method for Saturated Density, Moisture-Holding Capacity, and Porosity of Saturated Peat Materials1 This standard is issued under the fixed designation D2980; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision A number in parentheses indicates the year of last reapproval A superscript epsilon (´) indicates an editorial change since the last revision or reapproval Scope* D653 Terminology Relating to Soil, Rock, and Contained Fluids D2974 Test Methods for Moisture, Ash, and Organic Matter of Peat and Other Organic Soils D3740 Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used in Engineering Design and Construction D4753 Guide for Evaluating, Selecting, and Specifying Balances and Standard Masses for Use in Soil, Rock, and Construction Materials Testing D6026 Practice for Using Significant Digits in Geotechnical Data E11 Specification for Woven Wire Test Sieve Cloth and Test Sieves 1.1 This test method was designed to evaluate the aeration, water penetration, and water retention properties of peat under field conditions of water saturation by measurement of the saturated density, the moisture holding capacity, and the porosity 1.2 Units—The values stated in SI units are being regarded as standard The values given in parentheses are mathematical conversions to inch-pound units, which are provided for information only and are not considered standard 1.3 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026 1.3.1 The procedures used to specify how data are collected/ recorded or calculated in this standard are regarded as the industry standard In addition, they are representative of the significant digits that generally should be retained The procedures used 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 this standard to consider significant digits used in analysis methods for engineering design 1.4 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 and health practices and determine the applicability of regulatory limitations prior to use Terminology 3.1 Definitions: 3.1.1 For common definitions of common terms in this standard, refer to Terminology D653 Summary of Test Method 4.1 The test method sets up standardized conditions for measuring the volume and mass of saturated peat From these data, saturated volume, mass, moisture-holding capacity (on a mass and volume basis), dry peat volumes, and porosity can be determined Significance and Use 5.1 This test method measures the air-filled spaces (porosity) and the moisture-holding capacity of peat on both a mass and a volume basis under conditions of saturation If large spaces are present, water and air can penetrate easily If spaces are smaller, the water holding capacity is increased Water holding capacity is larger in humified peat materials (small inter-particulate spaces) (sapric soil), whereas water and airpenetration is larger in unhumified peat (larger inter-particulate spaces) (fibric soil) The spaces can also be an indication of the oxygen available to the plant roots As such, the interplay of the properties of moisture holding capacity and porosity dictate the best use of the harvested organic soil material as well as the best management practices for organic soils The moisture Referenced Documents 2.1 ASTM Standards:2 This test method is under the jurisdiction of ASTM Committee D18 on Soil and Rock and is the direct responsibility of Subcommittee D18.22 on Media for Plant Growth Current edition approved Feb 1, 2017 Published February 2017 Originally approved in 1971 Last previous edition approved in 2010 as D2980 – 04(2010) DOI: 10.1520/D2980-17 For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org For Annual Book of ASTM Standards volume information, refer to the standard’s Document Summary page on the ASTM website *A Summary of Changes section appears at the end of this standard Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959 United States D2980 − 17 Preparation of Sampling and Test Specimens Sampling, Test Specimens, and Test Units retention relationships of these soils are critical to decisions involving irrigation, drainage, and bearing capacity of these soil 7.1 Sample: 7.1.1 Obtain a sample as outlined in Section of Test Methods D2974 7.1.2 Air-dry the sample in accordance with Method B, 8.1.3.2 of Test Methods D2974 (air dried portion only) Determine and Record the moisture removed during air-drying as a percentage of the as-received mass to the nearest 0.1 % 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 7.2 Test Specimen: 7.2.1 Place a representative field sample about 300 g on a square rubber sheet, paper, or oil cloth 7.2.2 Reduce the sample to the quantity required for a specimen by quartering and place in a pre-tared moisture-proof container Work rapidly to prevent moisture losses 5.2 Water retention values are particularly important in the management of organic soils There is much confusion in the literature about the moisture retention values being expressed in various bases; as a percent by volume; as a percent of oven dry mass; or as the percent of the wet mass In some management decisions, it is necessary to express the water contents of organic soils on a volume basis because of their varied bulk densities, but because of the volume reduction occurring on drying, the water contents must also be expressed on a wet volume basis as collected in the field Whereas, in other management decisions, moisture retention values are best expressed on a dry mass basis For example, the difference in mass between the wet and oven dry sample is the moisture held These values are best expressed on a dry mass basis Water holding capacities show a marked difference due to the degree of decomposition in an organic soil The mass of water in fibric soil may be as much as 20 times the mass of the solid particles, whereas that held in a sapric soil contains less than twice the mass If the water holding capacity is expressed on a volume basis these differences are much less apparent Procedure 8.1 Determine the moisture content on a separate test specimen by Method I or II of Test Methods D2974 8.1.1 Determine the mass of the buret fitted with the plastic tube and screen Working rapidly to prevent moisture losses, mix the sample thoroughly, place on top of a 4-mesh sieve, and shake until sieving is complete Use only the portion that has passed through the sieve for the determination Firmly pack the buret with 250 mm (10 in.) of the material passing the 4-mesh sieve as follows: Attach the rubber stopper to the delivery end of the buret Add approximately 20-cm3 portions of the sample, firmly tapping on the rubber stopper times vertically from a height of 150 mm (6 in.) for a final height of 250 mm (10 in.) (This will ensure that the height of the final wet volume is 190 to 250 mm (7.5 to 10 in.)) Remove the stopper and weigh the buret to nearest g 8.1.2 Position the buret to use a sink as the drain Place a 20-L (5-gal) bottle equipped with a siphon device above the level of the buret Connect the clamped rubber tubing of the siphon device to the buret by inserting glass tubing about 125 mm (5 in.) and constricted at one end into the one-hole rubber stopper fitted tightly into the top of the buret Attach the rubber tubing with the pinch clamp to the delivery end of the buret Open both clamps and pass water through the sample for more than 24 h, maintaining a water reservoir over the sample at all times (Moss-type samples may float but gradually settle as the sample becomes wet.) After initial soaking, regulate the water flow through the column by adjusting the screw clamp at the delivery end of the buret (The in-flow of water should be about equal to the out-flow; a flow of about drop/s is suitable.) When the sample is saturated, close both clamps and let the sample settle in water for about The top surface of the sample should be as level as possible 8.1.3 Raise the buret and replace the rubber stopper on the delivery end of the buret with a 250-cm3 dispensing buret filled with water, using the rubber stopper for the connection Connect the two burets tightly, with no air leaks Remove the siphon device and open the outlet clamps on both burets to empty (The suction created is equivalent to about 38 mm (15 in.) of water Check for air leaks to ensure that the standard suction is exerted on the sample It is important to remove excess water as described.) Measure the height of the wet peat Apparatus 6.1 Dispensing Apparatus: 6.1.1 Two dispensing burets, 250-cm3 capacity in 1-cm3 subdivisions, 62-cm3 tolerance, pinch-cock type; 6.1.2 A one-hole No rubber stopper; 6.1.3 Straight polyethylene drying tube with serrated rubber tubing fittings, 150 mm long, 19 mm (3⁄4 in.) in outside diameter, 16 mm (5⁄8 in.) in inside diameter; 6.2 A 4-mesh sieve conforming to Specification E11; 6.3 Balance or Scale, a balance or scale for determining the mass of the soil having a minimum capacity of 500 g and meeting the requirements of Guide D4753 for a balance or scale of 0.01 g readability; 6.4 A pre-tared moisture-proof (air-tight) container; 6.5 A 5-gal (20-L) bottle equipped with a siphon device; 6.6 Stainless steel sieve circle about 16 mesh and 28.7 mm in diameter to be attached to one end of the drying tube and sealed (A soldering iron is useful.) Adjust the length of the tube to match conveniently the graduation of the buret; then cut the end without the sieve to allow for water drainage, and insert the tube into the dispensing buret with the sieve side up 6.7 A square piece of rubber sheet, paper, or oil cloth to aid in mixing sample D2980 − 17 The height should be 190 to 250 mm (7.5 to 10 in.) Record the volume in millilitres and determine the mass of the buret, the plastic tube with the sieve, and the wet peat to the nearest g Wet the sample again as above for more than h, drain by suction, record the volume, and mass Repeat until consistent results are obtained A 100 ~ V1P ! 10 Report: Test Data Sheet(s)/Form(s) 10.1 The methodology used to specify how data are recorded on the test data sheet(s)/form(s), is given below, is covered in 1.3 10.2 Record as a minimum the following general information (data): 10.2.1 Sample/specimen identifying information, such as description and manufacturer of the peat 10.2.2 Any special selection and preparation process 10.2.3 Technician name or initials, method used, and date Calculation 9.1 Calculate the saturated density, S, in grams per cubic centimetre as follows: As-received: Oven-dried: Wet: S W r /V w (1) S W d /V w (2) S W w /V w (3) 10.3 Record as a minimum the following test specimen data: 10.3.1 Report the saturated density to the nearest 0.01 g./cm3 (D6026) 10.3.2 Report the moisture holding capacity on both a dry mass and volume basis to the nearest whole number percentage (D6026) 10.3.3 Report the porosity to the nearest whole number percentage (D6026) where: Wr = mass of test specimen as received, g, Vw = wet volume, cm3, of oven-dried test specimen, Wd = mass g = Wr × (100 − M)/100, M = moisture, %, and Ww = mass of wet (saturated) test specimen, g 11 Precision and Bias 11.1 Precision—Test data precision is not presented due to the nature of materials tested Due to the nature of the soil or rock materials tested by this method It is either not feasible or too costly at this time to have ten or more laboratories participate in a round-robin testing program Also, it is not feasible or too costly to produce multiple specimens that have uniform physical properties Any variation observed in the data is just as likely to be due to specimen variation as to operator or laboratory testing variation 11.1.1 Subcommittee D18.22 is seeking any data from the users of this test method that might be used to make a limited statement on precision It welcomes proposals that would allow for development of a valid precision statement 9.2 Calculate the moisture-holding capacity in percent as follows: 9.2.1 Mass basis, W: As-received: Oven-dried: W @ ~ W w W r ! 100# /W r (4) W @ ~ W w W d ! 100# /W d (5) 9.2.2 Volume basis, V: V @ ~ W w W d ! 100# / ~ V w 1.0! (6) Where 1.0 = Density of Water (g/cm ) 9.3 Calculate the dry peat volume (density), P, in percent as follows: P ~ W d 100! / ~ V w 1.4! (8) 11.2 Bias—There is no accepted reference value for this test method, therefore, bias cannot be determined (7) Where 1.4 = Density of Peat (g/cm3) 12 Keywords 9.4 Calculate the porosity, A, in percent as follows: 12.1 moisture; moisture holding capacity; peat; porosity SUMMARY OF CHANGES In accordance with Committee D18 policy, this section identifies the location of changes to this standard since the last edition (D2980–04(2010)) that may impact the use of this standard (February 1, 2017) (7) Changed mL to cm3 (8) Updated Precision section (9) Added reference to D6026 (10) Updated Report section (11) Updated significance and use discussion (12) Updated Sample Preparation section (1) Removed Footnotes and (2) Corrected typos (3) Added Units section to Scope (4) Changed reference to “weigh” to “determine the mass of.” (5) Changed reference to “scallop” to “cut.” (6) Added “Density” to “volume mass” and “dry peat volume” for clarification D2980 − 17 ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentioned in this standard Users of this standard are expressly advised that determination of the validity of any such patent rights, and the risk of infringement of such rights, are entirely their own responsibility This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and if not revised, either reapproved or withdrawn Your comments are invited either for revision of this standard or for additional standards and should be addressed to ASTM International Headquarters Your comments will receive careful consideration at a meeting of the responsible technical committee, which you may attend If you feel that your comments have not received a fair hearing you should make your views known to the ASTM Committee on Standards, at the address shown below This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the above address or at 610-832-9585 (phone), 610-832-9555 (fax), or service@astm.org (e-mail); or through the ASTM website (www.astm.org) Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http://www.copyright.com/