ASTM D2395-2014e1 Standard Test Methods for Density and Specific Gravity (Relative Density) of Wood and Wood-Based Materials《木材和木基材料的密度和比重 (相对密度) 的标准试验方法》.pdf

《ASTM D2395-2014e1 Standard Test Methods for Density and Specific Gravity (Relative Density) of Wood and Wood-Based Materials《木材和木基材料的密度和比重 (相对密度) 的标准试验方法》.pdf》由会员分享，可在线阅读，更多相关《ASTM D2395-2014e1 Standard Test Methods for Density and Specific Gravity (Relative Density) of Wood and Wood-Based Materials《木材和木基材料的密度和比重 (相对密度) 的标准试验方法》.pdf（13页珍藏版）》请在麦多课文档分享上搜索。

1、Designation: D2395 141Standard Test Methods forDensity and Specific Gravity (Relative Density) of Wood andWood-Based Materials1This standard is issued under the fixed designation D2395; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revisio

2、n, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S. Department of Defense.1NOTECorrections were made ed

3、itorially in October 2015.1. Scope1.1 These test methods cover the determination of thedensity and specific gravity (relative density) of wood andwood-based materials to generally desired degrees of accuracyand for specimens of different sizes, shapes, and moisturecontent conditions. The method titl

4、e is indicative of theprocedures used or the specific area of use.SectionTest Method AVolume by Measurement 7Test Method BVolume by Water Immersion 8Test Method CFlotation Tube 9Test Method DForstner Bit 10Test Method EIncrement Core 11Test Method FChips 121.2 This standard does not purport to addre

5、ss all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D9 Terminology

6、Relating to Wood and Wood-Based Prod-uctsD2555 Practice for Establishing Clear Wood Strength ValuesD4442 Test Methods for Direct Moisture Content Measure-ment of Wood and Wood-Based MaterialsD5456 Specification for Evaluation of Structural CompositeLumber ProductsD7438 Practice for Field Calibration

7、 and Application ofHand-Held Moisture MetersE1547 Terminology Relating to Industrial and SpecialtyChemicals2.2 Other Standards:CAN/CSA O86 Engineering Design in Wood3ANSI/AWC National Design Specification for Wood Con-struction43. Terminology3.1 Definitions:3.1.1 For definitions of terms used in thi

8、s standard, refer toTerminology D9.3.2 Definitions of Terms Specific to This Standard:3.2.1 density, kg/m3, g/cm3or lb/ft3,nthe mass of aunit volume of a specimen at specified moisture content.NOTE 1The moisture content is specified for both mass and volume.For further discussion, see Appendix X3.3.

9、2.1.1 density at moisture content Mdensity based on themass of a specimen including moisture and its volume at thesame moisture content.NOTE 2The mass and volume at 12 % moisture content are frequentlyused.3.2.1.2 density, basic or conventional, bdensity based onthe oven-dry mass of a specimen and i

10、ts green volume.3.2.1.3 density, oven-dry or in the absolute dry condition,0density based on the oven-dry mass of a specimen and itsoven-dry volume.3.2.2 green volume, nthe volume of wood specimenbefore any shrinkage occurs due to drying to moisture contentbelow the fiber saturation point (about 30

11、%).NOTE 3Green volume may also be obtained by water soaking ofpartially dry wood specimens until they reach fully swollen conditionabove the fiber saturation point (e.g., see 12.2.3.1). See Appendix X3. Thefiber saturation point of wood averages approximately 30% moisture1These test methods are unde

12、r the jurisdiction of ASTM Committee D07 onWood and are the direct responsibility of Subcommittee D07.01 on FundamentalTest Methods and Properties.Current edition approved May 1, 2014. Published June 2014. Originallyapproved in 1965. Last previous edition approved in 2007 as D2395 07a1. DOI:10.1520/

13、D2395-14E01.2For 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.3Available from CSA Group, 5060 Spectrum Way, Mis

14、sissauga, ON L4W 5N6,Canada, http:/www.csa.ca.4Available fromAmerican Wood Council (AWC) 222 Catoctin Circle, SE, Suite201 Leesburg, VA 20175, www.awc.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1content, but in individual spec

15、ies and individual pieces of wood it can varyby several percentage points from that value.3.2.3 moisture content, M %the amount of water con-tained in a specimen, expressed as a percentage of its oven-drymass.3.2.4 specific gravity (relative density), S, nthe ratio of theoven-dry mass of a specimen

16、to the mass of a volume of waterequal to the volume of the specimen at a specified moisturecontent.NOTE 4The volume may be that in the oven-dry, partially dry, orgreen (fully swollen) condition. Further in this standard, the terms specificgravity and relative density are used interchangeably. For fu

17、rtherdiscussion, see Appendix X3.3.2.4.1 specific gravity at moisture content M, nspecificgravity based on the oven-dry mass of a specimen and itsvolume at a specified moisture content between the oven-drycondition and the fiber saturation point.NOTE 5The volume at 12 % moisture content is frequentl

18、y used.3.2.4.2 specific gravity, basic (or green), Sb,nspecificgravity based on the oven-dry mass of a specimen and its greenvolume.3.2.4.3 specific gravity, oven-dry or on oven-dry basis, S0,nspecific gravity based on the oven-dry mass of a specimenand its oven-dry volume.4. Summary of Test Methods

19、4.1 The precision of test results obtained on a representativespecimen depends upon the precision of the measurementsmade. Method A is used for precise measurements when thespecimens are carefully prepared and regular in shape. MethodB is used for precise measurements if the specimens areirregularly

20、 shaped and if due care is taken to prevent sorptionof water. Test Method C is an approximate method that ispermitted for use as part of a production procedure or in othersituations where less precision is acceptable. Test Methods Dand E are especially adapted to density or specific gravitymeasureme

21、nts of living trees or of in-place elements, and theprecision of the result is dependent upon the care used inobtaining the specimen. Test Method F is a specific procedurefor wood chips.5. Significance and Use5.1 Density and specific gravity are cornerstone terms thathelp define many useful properti

22、es of wood and wood-basedproducts. These terms designate concepts that have distinctdefinitions though they relate to the same characteristic (massin a unit volume). Generally, in the US and Canada, density ofwood is measured in terms of specific gravity,orrelativedensity. In the wood-based composit

23、es industry and interna-tionally the term density is often preferred.5.2 The basic density and basic specific gravity of wood areused in the forestry industry for calculating the oven-dryweight of wood fiber contained in a known wood volume ofvarious wood species. Thus, it serves as an indicator of

24、theamount of wood pulp that could be produced, the workabilityof the material or its shipping weight. This information isreferenced in various resources, including Wood Handbook.5Note that specific gravity varies within a tree, between trees,and between species. Since the specific gravity of wood ce

25、llwall substance is practically constant for all species (approxi-mately 1.53), it is apparent that individual specific gravityvalue is indicative of the amount of wood cell wall substancepresent. It affords a rapid and valuable method for selection ofwood for specific uses. In US and Canadian build

26、ing codes, theoven-dry specific gravity is correlated to various strengthcharacteristics of wood products (e.g., compression perpen-dicular to grain, shear strength and fastener holding capacity).5.3 It is often desirable to know the density or specificgravity of a living tree, a structural member a

27、lready in place, alog cross section, a segment of a research element, or theearlywood or latewood layer. Therefore, it is possible thatspecimens will be large or small, regular or irregular in shape,and at a variety of moisture contents. These test methods giveprocedures that include all of these va

28、riables and provides forcalculation of density and specific gravity values to degrees ofprecision generally needed.5.4 In the wood-based composites industry, the productdensity or specific gravity also provides an important indicatorof potential product attributes. For wood-based materials, thesame

29、test methods are used; however, the measurementstypically combine the mass from the wood substance with anyresin, wax, or other solid additives present in the material.These properties are not to be confused with equivalent specificgravity of structural composite lumber used to characterize itsfaste

30、ner-holding capacity determined in accordance withD5456.6. Test Specimens6.1 The test specimens shall be fully representative of thematerial from which they are taken. The specimen size shall besuch that accurate measurements of mass and volume are easyto attain. Where other standards specify the lo

31、cation and size oftest specimens, these requirements shall be carefully followed.The specimens shall be carefully cut from the larger element toensure clean-cut surfaces. All loose fibers shall be carefullyremoved before the specimen is weighed and measured. Thespecimen shall be free from knots, and

32、 if pitch or otherinfiltrates are present, this shall be noted in the report or theyshall be extracted before taking measurements and weighing.6.2 MeasurementsThe dimensions of test specimens shallbe measured to a precision of 60.3 % or less, and the massshall be determined to a precision of 60.2 %

33、or less. Wheredrying of specimens is required, this shall be done in a forcedconvection oven that can be maintained at 103 6 2Cthroughout the drying chamber for the time required to dry thespecimen to reach practical equilibrium (see Note 6). The ovenshall be vented to allow the evaporated moisture

34、to escape.NOTE 6For most specimens of wood, wood structural panels andstructural composite lumber 1 in. (25 mm) in length parallel to grain,drying for 24 h in an oven having good air circulation and exchange willbe sufficient to reach practical equilibrium (no more than 0.2% mass5Forest Products Lab

35、oratory General Technical Report FPL-GTR-190, WoodHandbook: Wood as Engineering Material, Forest Products Society, 2010.D2395 1412change over 8 h period of drying). For other wood-based materials, thedrying time should be established by test. For further discussion, seeAppendix X3.7. Test Method AVo

36、lume by Measurement7.1 Applicability:7.1.1 This procedure is adaptable to any size of specimen atany moisture content. The specimen shall be regular in shapewith right-angle corners for determination of volume by linealmeasurement. If the surfaces of the specimen are smooth andsufficient measurement

37、s are taken, the volume can be obtainedwith high precision. Special care shall be taken in measurementof very small or thin specimens. Volume of irregular orrough-surfaced specimens shall be obtained by Test Method B.7.2 Procedures:7.2.1 VolumeMeasure the length, width, and thickness ofthe specimen

38、in accordance with 6.2 in a sufficient number ofplaces to ensure a precise indication of volume.7.2.2 Initial mass, (mM)Determine the initial mass of thespecimen at the time of test in accordance with 6.2.7.2.3 Oven-dry mass (m0)Oven-dry mass of the specimenshall be determined by drying to practical

39、 equilibrium inaccordance with 6.2 or by calculation (13.1.2) in specialsituations (7.2.4.4).7.2.4 Moisture ContentDetermine the moisture content(M) of the specimen to permit description of the basis on whichthe density or specific gravity is computed. Test MethodsD4442 and D7438 indicate procedures

40、 that shall be used.7.2.4.1 Small SpecimensThe entire specimen shall be usedfor determination of moisture content in accordance withD4442.7.2.4.2 Intermediate SpecimensWhen the specimen is of asize that is unsuitable for moisture content determinations (thetime to oven-dry to constant mass would be

41、excessive), asegment shall be cut from the specimen in accordance with 6.1for moisture content measurement using methods D4442.Select this segment so that its moisture content is representa-tive of that of the larger specimen. Where possible in woodelements and structural composite lumber, the moist

42、ure contentspecimen shall be of full cross-sectional dimensions approxi-mately 1 in. (25 mm) in length (parallel to grain). In sheetmaterials the specimen shall be equal in thickness to thethickness of the material and 3 by 6 in. (76 by 122 mm) in size.7.2.4.3 Structural ElementsIn full-size members

43、, themoisture content shall be determined on a segment cut from themember in accordance with 6.1. It shall be of full cross-sectional dimensions and approximately 1 in. (25 mm) inlength parallel to grain, and shall be selected from a represen-tative area of the member (see Note 7).NOTE 7The specimen

44、s should be cut in the area of interest. Wherepossible, avoid the effects of end drying.7.2.4.4 Special SituationsWhere the specimen or elementcannot be cut to secure a moisture content segment, anapproximate moisture content shall be obtained through the useof a moisture meter in accordance with Te

45、st Methods D7438(see Note 8). The use of moisture meters shall not be permittedfor materials other than wood.NOTE 8Since the moisture content value obtained with moisturemeter is approximate, it should be recognized that the specific gravityvalues obtained are approximate.8. Test Method BVolume by W

46、ater Immersion8.1 Applicability:8.1.1 This procedure is particularly adaptable to specimensof irregular shape or having a rough surface (see Note 9).NOTE 9Limitations on specimen size are based primarily on size ofimmersion tanks available. In small size specimens, less than 1 cm3involume, air bubbl

47、es adhering to the specimen surface can result inconsiderable error in volume measurement and thus in the computeddensity or specific gravity value. Freshly cut green wood will not absorbappreciable quantities of water during the brief immersion period. If anydrying has taken place, the surface of t

48、he specimen needs to be sealedbefore immersion in water or else the volumetric displacement of thespecimen will be in error in an amount equal to the volume of waterabsorbed by the wood.8.2 Procedures:8.2.1 Initial mass (mM)Determine the initial mass of thespecimen at time of test in accordance with

49、 6.2.8.2.2 VolumeDetermine the volume of the specimen bymeasuring the volume or the mass of the water displaced by thespecimen using one of the following modes. The mass of waterin grams is numerically equal to its volume in cubic centime-ters. Unless the volume is determined on a specimen of greenwood, the surfaces of the specimen shall be adequately sealed(see 8.2.2.5).8.2.2.1 Mode IPlace the specimen in a tank of knownvolume and add sufficient water to fill the tank with thespecimen being fully submerged. Then remove the speci