ASTM D2395-2017 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 D2395-2017 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 D2395-2017 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（19页珍藏版）》请在麦多课文档分享上搜索。

1、Designation: D2395 141D2395 17Standard 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

2、 revision, 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.1 NOTECorrections wer

3、e made editorially in October 2015.1. Scope1.1 These test methods cover the determination of the density and specific gravity (relative density) of wood and wood-basedmaterials to generally desired degrees of accuracy and for specimens of different sizes, shapes, and moisture content conditions.The

4、test method title is indicative of the procedures used or the specific area of use.SectionTest Method AVolume by Measurement 7Test Method AVolume by Measurement 8Test Method BVolume by Water Immersion 8Test Method BVolume by Water Immersion 9Test Method CFlotation Tube 9Test Method CFlotation Tube 1

5、0Test Method DForstner Bit 10Test Method DForstner Bit 11Test Method EIncrement Core 11Test Method EIncrement Core 12Test Method FChips 12Test Method FChips 13Test Method GFull-Size Members 141.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. I

6、t is the responsibilityof the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and determine theapplicability of regulatory limitations prior to use.1.3 This international standard was developed in accordance with internationally recognized prin

7、ciples on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D9 Terminology Relating to Wood a

8、nd Wood-Based ProductsD2555 Practice for Establishing Clear Wood Strength ValuesD4442 Test Methods for Direct Moisture Content Measurement of Wood and Wood-Based MaterialsD5456 Specification for Evaluation of Structural Composite Lumber ProductsD7438 Practice for Field Calibration and Application of

9、 Hand-Held Moisture MetersE1547 Terminology Relating to Industrial and Specialty Chemicals1 These test methods are under the jurisdiction ofASTM Committee D07 on Wood and are the direct responsibility of Subcommittee D07.01 on Fundamental Test Methodsand Properties.Current edition approved May 1, 20

10、14Oct. 15, 2017. Published June 2014November 2017. Originally approved in 1965. Last previous edition approved in 20072014 asD2395 07aD2395 141. DOI: 10.1520/D2395-14E01.10.1520/D2395-17.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceas

11、tm.org. For Annual Book of ASTM Standardsvolume information, refer to the standardsstandards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous versi

12、on. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM Internationa

13、l, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States12.2 Other Standards:CAN/CSA O86 Engineering Design in Wood3ANSI/AWC National Design Specification for Wood Construction43. Terminology3.1 Definitions:3.1.1 For definitions of terms used in this standard, refer to

14、Terminology D9.3.2 Definitions of Terms Specific to This Standard:3.2.1 density, kg/m3, g/cm3 or lb/ft3,nthe mass of a unit volume of a specimen at specified moisture content.NOTE 1The moisture content is specified for both mass and volume. For further discussion, see Appendix X3.3.2.1.1 density at

15、moisture content Mdensity based on the mass of a specimen including moisture and its volume at the samemoisture content.NOTE 2The mass and volume at 12 % moisture content are frequently used.3.2.1.2 density, basic or conventional, bdensity based on the oven-dry mass of a specimen and its green volum

16、e.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 specimen before any shrinkage occurs due to drying to moisture content below thefiber saturation point (about 30 %).NOTE 3Gre

17、en volume may also be obtained by water soaking of partially dry wood specimens until they reach fully swollen condition above thefiber saturation point (e.g., (for example, see 12.2.3.113.2.3.1). See Appendix X3. The fiber saturation point of wood averages approximately 30%moisture content, but in

18、individual species and individual pieces of wood it can vary by several percentage points from that value. For further discussion,see Appendix X3.3.2.3 moisture content, M %the amount of water contained in a specimen, expressed as a percentage of its oven-dry mass.3.2.4 specific gravity (relative de

19、nsity), S, nthe ratio of the oven-dry mass of a specimen to the mass of a volume of waterequal to the volume of the specimen at a specified moisture content.NOTE 4The volume may be that in the oven-dry, partially dry, or green (fully swollen) condition. Further in this standard, the terms specific g

20、ravityand relative density are used interchangeably. For further discussion, see Appendix X3.3.2.4.1 specific gravity at moisture content M, nspecific gravity based on the oven-dry mass of a specimen and its volume ata specified moisture content between the oven-dry condition and the fiber saturatio

21、n point.NOTE 5The volume at 12 % moisture content is frequently used.3.2.4.2 specific gravity, basic (or green), Sb, nspecific gravity based on the oven-dry mass of a specimen and its green volume.3.2.4.3 specific gravity, oven-dry or on oven-dry basis, S0, nspecific gravity based on the oven-dry ma

22、ss of a specimen andits oven-dry volume.4. Summary of Test Methods4.1 The precision of test results obtained on a representative specimen depends upon the precision of the measurements made.Test Method A is used for precise measurements when the specimens are carefully prepared and regular in shape.

23、 Test Method Bis used for precise measurements if the specimens are irregularly shaped and if due care is taken to prevent sorption of water. TestMethod C is an approximate test method that is permitted for use as part of a production procedure or in other situations whereless precision is acceptabl

24、e.Test Methods D and E are especially adapted to density or specific gravity measurements of living treesor of in-place elements, and the precision of the result is dependent upon the care used in obtaining the specimen. Test MethodF is a specific procedure for wood chips. Test Method G provides a p

25、rocedure to estimate the overall density or specific gravityof a full-size rectangular member that includes typical growth and manufacturing characteristics.5. Significance and Use5.1 Density and specific gravity are cornerstone terms that help define many useful properties of wood and wood-basedpro

26、ducts.materials. These terms designate concepts that have distinct definitions though they relate to the same characteristic (massin a unit volume). Generally, in the US and Canada, density of wood is measured in terms of specific gravity, or relative density.In the wood-based composites industry an

27、d internationally the term density is often preferred.5.2 The basic density and basic specific gravity of wood are used in the forestry industry for calculating the oven-dry weightof wood fiber contained in a known wood volume of various wood species. Thus, it serves as an indicator of the amount of

28、 wood3 Available from CSA Group, 5060 Spectrum Way, Mississauga, ON L4W 5N6, Canada, http:/www.csa.ca.4 Available from American Wood Council (AWC) 222 Catoctin Circle, SE, Suite 201 Leesburg, VA 20175, www.awc.org.D2395 172pulp that could be produced, the workability of the material or its shipping

29、weight. This information is referenced in variousresources, including Wood Handbook.5 Note that specific gravity varies within a tree, between trees, and between species. Sincethe specific gravity of wood cell wall substance is practically constant for all species (approximately 1.53), it is apparen

30、t thatindividual specific gravity value is indicative of the amount of wood cell wall substance present. It affords a rapid and valuabletest method for selection of wood for specific uses. In US and Canadian building codes, the oven-dry specific gravity is correlatedto various strength characteristi

31、cs of wood products (e.g., (for example, compression perpendicular to grain, shear strength andfastener holding capacity).5.3 It is often desirable to know the density or specific gravity of a living tree, a structural member already in place, a log crosssection, a segment of a research element, or

32、the earlywood or latewood layer. Therefore, it is possible that specimens will be largeor small, regular or irregular in shape, and at a variety of moisture contents. These test methods give procedures that include allof these variables and provides for calculation of density and specific gravity va

33、lues to degrees of precision generally needed.5.4 In the wood-based composites industry, the product density or specific gravity also provides an important indicator ofpotential product attributes. For wood-based materials, the same test methods are used; however, the measurements typicallycombine t

34、he mass from the wood substance with any resin, wax, or other solid additives present in the material. These propertiesare not to be confused with equivalent specific gravity of structural composite lumber used to characterize its fastener-holdingcapacity determined in accordance with Specification

35、D5456.6. Test Specimens6.1 The test specimens shall be fully representative of the material from which they are taken. The specimen size shall be suchthat accurate measurements of mass and volume are easy to attain. Where other standards specify the location and size of testspecimens, these requirem

36、ents shall be carefully followed. The With the exception of Test Method G, the specimens shall becarefully cut from the larger element to ensure clean-cut surfaces. All loose fibers shall be carefully removed before the specimenis weighed and measured. The specimen shall be free from knots, and if p

37、itch or other infiltrates are present, this shall be notedin the report or they shall be extracted before taking measurements and weighing. The specimens for Test Method G shall befull-size rectangular members. When Test Method G is used with solid wood lumber, the specimens shall be permitted to in

38、cludeknots, wane, edge easing, pitch, or other typical growth or manufacturing characteristics.6.2 MeasurementsThe dimensions of test specimens shall be measured to a precision of 60.3 % or less, and the mass shallbe determined to a precision of 60.2 % or less. Where drying of specimens is required,

39、 this shall be done in a forced convectionoven that can be maintained at 103 6 2C throughout the drying chamber for the time required to dry the specimen to reachpractical equilibrium (see equilibrium. Note 6). The oven shall be vented to allow the evaporated moisture to escape.NOTE 6For most specim

40、ens of wood, wood structural panels and structural composite lumber 1 in. (25 mm) in length parallel to grain, drying for24 h in an oven having good air circulation and exchange will be sufficient to reach practical equilibrium (no more than 0.2% mass change over 8 h periodof drying). For other wood

41、-based materials, the drying time should be established by test. For further discussion, see Appendix X3.7. Moisture Content7.1 The moisture content (M) of the specimens shall be measured to identify the basis on which the density or specific gravityis determined. The method of determination of the

42、moisture content depends on the size of the specimen and the purpose of thetest.7.1.1 Oven DryingThe moisture content shall be determined using the oven-dry procedures ofTest Method D4442.With smallspecimens of convenient size that can be oven-dried within a reasonable timeframe, the entire piece sh

43、all be used for the moisturecontent determination. With larger specimens that cannot be conveniently oven-dried, at least one representative segment shall becut from the full-size specimen for the moisture content determination. In this case, the moisture content specimens shall be as largeas can be

44、 practically dried in a reasonable timeframe and cut away from the member ends, wherever possible.7.1.2 Moisture MeterWhere a large solid wood specimen cannot be cut to secure a moisture content segment for oven drying,an approximate moisture content shall be permitted to be obtained through the use

45、 of a moisture meter in accordance with PracticeD7438. The meter readings shall be corrected for temperature and species. The use of moisture meters shall not be permitted formaterials other than solid wood.NOTE 7Since the moisture content value obtained with moisture meter is approximate, it should

46、 be recognized that the density and specific gravityvalues obtained using this method are approximate. To improve accuracy, the oven-drying method of moisture content determination should be usedwhenever possible.8. Test Method AVolume by Measurement8.1 Applicability:8.1.1 This procedure is adaptabl

47、e to any size of clear wood specimen at any moisture content. The specimen shall be regularin shape with right-angle corners for determination of volume by lineallinear measurement. If the surfaces of the specimen are5 Forest Products Laboratory General Technical Report FPL-GTR-190, Wood Handbook: W

48、ood as Engineering Material, Forest Products Society, 2010.D2395 173smooth and sufficient measurements are taken, the volume can be obtained with high precision. Special care shall be taken inmeasurement of very small or thin specimens. Volume of irregular or rough-surfaced specimens shall be obtain

49、ed by Test MethodB.8.2 Procedures:8.2.1 VolumeMeasure the length, width, and thickness of the specimen in accordance with 6.2 in a sufficient number of placesto ensure a precise indication of volume.8.2.2 Initial mass,Mass, (mM)Determine the initial mass of the specimen at the time of test in accordance with 6.2.8.2.3 Oven-dry massMass (m0)Oven-dry mass of the specimen shall be determined by drying to practical equilibrium inaccordance with 6.2 or by calculation (in accordance with 13.1.215.1.2) in special situations if a moi