1、Designation: D 4531 86 (Reapproved 2002)Standard Test Methods forBulk Density of Peat and Peat Products1This standard is issued under the fixed designation D 4531; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last re
2、vision. 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 These test methods cover the determination of the bulkdensity of both peat in its natural state and peat products (Note1). T
3、hese test methods consist of defining a volume of peat anddetermining the mass of that specific volume. The difference inthe respective methods is in the procedures employed todetermine the peat volume.NOTE 1Test Method D 2978 is used for specifying the volumerepresented by a quantity of loose proce
4、ssed peat or the volume of a peatbale.1.2 Method AThis method, the core method, covers thedetermination of the bulk density of an undisturbed core of peattaken with a piston sampler or other suitable core sampler(Sections 6 and 7).1.3 Method BThis method, the paraffin wax method,covers the determina
5、tion of the bulk density of undisturbedclods or irregular pieces of wet peat and compressed peatproducts (Sections 8 and 9).1.4 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 establish appr
6、o-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:D 2974 Test Methods for Moisture, Ash, and Organic Mat-ter of Peat and Other Organic Soils2D 2978 Test Method for Volume of Processed Peat Materi-als
7、23. Terminology3.1 Definitions:3.1.1 bulk density, rtotal mass (solids plus water) per unitof total volume of a peat at a given moisture condition.3.1.2 dry density, rdmass of dry organic and mineralmatter per unit of total volume of a peat at a given moisturecondition.NOTE 2In many peat science app
8、lications and publications, the termdefined here as “dry density” in accordance with common geotechnicalengineering usage is referred to as “bulk density”. Care is necessary todistinguish which definition is being used when such a term is encoun-tered.4. Significance and Use4.1 These test methods pr
9、ovide uniform procedures fordetermining the bulk density of in situ peat and processed peatproducts. The bulk density is of use in the calculation of in situstresses for engineering analysis and in quantifying the amountof material present when considering peat as a resource. In thelatter case, it i
10、s necessary to consider the moisture condition forwhich the bulk density was determined; a more useful param-eter to consider may well be the dry density, rd.5. Apparatus5.1 Drying OvenA thermostatically controlled dryingoven maintained at a temperature of 105 6 5C.5.2 BalancesBalances sensitive to
11、0.01 g for samples lessthan 100 g, sensitive to 0.1 g for samples between 100 g and1000 g, or sensitive to 1 g for samples over 1000 g.5.3 Moisture Content ContainersSuitable containers forlaboratory moisture content determinations.5.4 Plastic Sample Bags or Sampling Jars.5.5 SamplerPiston sampler o
12、r other suitable coring devicewhich will give a reasonably undisturbed cylindrical sample.NOTE 3Samples taken with the Macaulay type peat sampler aresemicylindrical in shape and relatively undisturbed. They may also beused in this method of determination.5.6 Sharp KnifeAn electric knife or barbers r
13、azor will bebest for laboratory work.5.7 Paraffn Wax, maintained at a temperature between 60and 70C, for use in Method B only.5.8 Graduated Cylinder, for use in Method B only.METHOD ACORE METHOD6. Procedure6.1 Take a representative reasonably undisturbed core ofpeat with a piston sampler or other co
14、ring device.1These test methods are under the jurisdiction of ASTM Committee D18 on Soiland Rock and are the direct responsibility of Subcommittee D18.22 on Soil as aMedium for Plant Growth.Current edition approved Feb. 24, 1986. Published May 1986.2Annual Book of ASTM Standards, Vol 04.08.1Copyrigh
15、t ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.2 With a sharp knife, cut specimens of no less than 50 mmin length from the various layers included in the core. Measureand record the specimen length to the nearest millimetre.6.3 For samples
16、 extruded in the field, place the specimeninto a plastic bag or sampling jar and seal to prevent moistureloss.6.4 Transfer the whole specimen and any free water to amoisture content container in the laboratory and obtain andrecord the moist mass of peat, M, to the sensitivity of thebalance used.6.5
17、Dry the specimen in an oven at 105C until a constantmass is reached. Record the mass of dry peat, Ms.7. Calculation7.1 The bulk density, r, is calculated as follows:r5M/AL! g/cm3(1)where:M = mass of the wet peat sample, g,L = length of sample, cm, andA = cross-sectional area of sample, as determined
18、 fromthe diameter and form of the sampling device, cm2.7.2 The moisture content, wd, by dry mass of the specimenis calculated as follows for engineering purposes:wd5 M 2 Ms/Ms(2)where:Ms= mass of the oven dried peat specimen, g.7.2.1 The moisture content, wt, may also be expressed interms of total m
19、ass, and is then calculated as follows:wt5 M 2 Ms/M (3)7.2.2 It is of the utmost importance that the approach takenin calculating moisture contents be specified when reportingresults or when the term is first used in a report.7.3 The dry density, rd, is calculated as follows:rd5 Ms/AL! g/cm3(4)METHO
20、D BPARAFFIN WAX METHOD8. Procedure8.1 Take a representative reasonably undisturbed sample ofthe peat and trim it into as smooth a shape as possible. Weighand record the moist mass of the peat sample, M.8.2 Dip the sample momentarily into melted paraffin main-tained at a temperature between 60 and 70
21、C. Allow the excessparaffin to drain and the coating to dry. Repeat the dipping anddrying until a continuous coating is formed.8.3 Obtain and record the mass of the paraffin coated peatsample, Mpc.8.4 Submerge the coated sample in water in a graduatedcylinder and determine the volume of the paraffin
22、 coatedsample, Vpcby observing the volume of water displaced.8.5 Remove the paraffin coating from the peat sample usinga sharp knife.8.6 Place the remainder of the sample in a moisture contentcontainer and record the moist mass of the peat, M8 to theaccuracy specified for the balance used.8.7 Dry th
23、e sample in an oven at 105C until a constantmass is reached. Record the mass of dry peat, Ms.9. Calculation9.1 To determine the bulk density of the peat, r, a correctionfor the volume of the paraffin coating must be made as follows:Mass of paraffin coating 5 Mp5 Mpc2 M! (5)Volume of paraffin coating
24、 5 Vp5 Mp/rp!where:Mpc= mass of paraffin coated sample, grp= density of paraffin, g/cm3, andM = mass of peat sample, g.Volume of peat sample 5 V 5 Vpc2 Vp! (6)Bulk density, r5M/V!where:Vpc= volume of paraffin coated sample, cm3.9.2 The moisture content, wd, in this test method must beobtained in ter
25、ms of dry mass to allow the dry density, rd,tobecalculated.wd5 M8 2 Ms/Ms(7)where:M8 = moist mass of peat removed from paraffin, g, andMs= mass of dry peat, g.9.3 The dry density, rd, of the peat is calculated as follows:rd5 r/1 1 wd! (8)where:wd= moisture content in terms of oven dry mass.10. Repor
26、t10.1 The report shall include the following:10.1.1 Report the bulk density, r, and the dry density, rdtothe nearest 0.01 g/cm3and also state the method used todetermine.10.1.2 Moisture content, w, to the nearest 0.1 %. It is of theutmost importance that it be stated whether the moisturecontent is i
27、n terms of the dry mass or the total mass of the peat.11. Precision and Bias11.1 PrecisionThe subcommittee is seeking pertinent datafrom users of the test method to determine the precision of thistest method.11.2 BiasSince there is no accepted reference materialsuitable for determining the bias for
28、the procedure, bias has notbeen determined.12. Keywords12.1 bulk density; core sampling; paraffin-wax displace-ment method; peat; peat productsD 4531 86 (2002)2ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this stan
29、dard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof 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 revie
30、wed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsibl
31、e technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake 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 aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).D 4531 86 (2002)3
