ASTM D2395-2014 Standard Test Methods for Density and Specific Gravity &40 Relative Density&41 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 D2395-2014 Standard Test Methods for Density and Specific Gravity &40 Relative Density&41 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 D2395-2014 Standard Test Methods for Density and Specific Gravity &40 Relative Density&41 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 07a1D2395 14Standard 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 o

2、f 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 NOTEEditorial corr

3、ections were made throughout in October 2008.1. 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 condi

4、tions.The method title is indicative of the procedures 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 12SectionTest Method AV

5、olume 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 address all of the safety concerns, if any, associated with its use. It is the responsibilit

6、yof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D9 Terminology Relating to Wood and Wood-Based ProductsD2555 Practice for Establishing Clear Wood Streng

7、th ValuesD4442 Test Methods for Direct Moisture Content Measurement of Wood and Wood-Base MaterialsD5456 Specification for Evaluation of Structural Composite Lumber ProductsD4444D7438 Test Method for Laboratory Standardization and CalibrationPractice for Field Calibration and Application ofHand-Held

8、 Moisture MetersE1547 Terminology Relating to Industrial and Specialty Chemicals2.2 Other Standards:CAN/CSA O86 Engineering Design in Wood3ANSI/AF however, the measurements typicallycombine the mass from the wood substance with any resin, wax, or other solid additives present in the material. These

9、propertiesare not to be confused with equivalent specific gravity of structural composite lumber used to characterize its fastener-holdingcapacity determined in accordance with D5456.6. Test Specimens6.1 The specific gravity test specimens shall be fully representative of the material from which the

10、y are taken. The specimensize shall be such that accurate measurements of mass and volume are easy to attain. Where other standards specify the locationand size of specific gravity test specimens, these requirements shall be carefully followed. The specimens shall be carefully cutfrom the larger ele

11、ment to ensure clean-cut surfaces. All loose fibers shall be carefully removed before the specimen is weighedand measured. The specimen shall be free from knots, and if pitch or other infiltrates are present, this shall be noted in the reportor they shall be extracted before specific gravity values

12、are obtained.taking measurements and weighing.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, this shall be done in an oven a forcedconvection

13、 oven that can be maintained at 103 6 2C. (For most panel materials and wood specimens 1 in. (25 mm) in lengthparallel to grain, drying for 48 h in an oven2C throughout the drying chamber for the time required to dry the specimen to reachpractical equilibrium (see Note 6having good air circulation a

14、nd exchange will be sufficient to reach constant mass.) ). The ovenshall be vented to allow the evaporated moisture to escape.NOTE 6For most specimens 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

15、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-based materials, the drying time should be established by test. For further discussion, see Appendix X3.7. TEST METHOD ATest Method AVolumeVOLUME BY MEA

16、SUREMENT by Measurement7.1 Applicability:7.1.1 Shape of SpecimenThe specimen mustThis procedure is adaptable to any size of specimen at any moisture content. Thespecimen shall be regular in shape with right-angle corners for determination of volume by lineal measurement. The procedure isadaptable to

17、 any size of specimen or to specimens of any moisture content. If the surfaces of the specimen are smooth and sufficientmeasurements are taken, the volume can be obtained with considerable accuracy.high precision. Special care mustshall be takenin measurement of very small or thin specimens. Volume

18、of irregular or rough-surfaced specimens shouldshall be obtained by TestMethod B.5 Forest Products Laboratory General Technical Report FPL-GTR-190, Wood Handbook: Wood as Engineering Material, Forest Products Society, 2010.D2395 1437.2 Procedures:7.2.1 MeasurementVolumeMeasure the length (length, wi

19、dth,L), width ( w), and thickness (t) of the specimen in accordancewith 6.2 in a sufficient number of places to ensure an accuratea precise indication of volume. In small specimens, uniform in size,one or two measurements of each dimension will suffice; in larger specimens the number of measurements

20、 will depend on theuniformity of the specimen, but at least three measurements of each dimension will be required.7.2.2 MassInitial mass, (mM)Determine the initial mass (mM) of the specimen at the time of test in accordance with 6.2.7.2.3 Moisture ContentOven-dry mass (m0)Determine the moisture cont

21、ent (Oven-dry mass M) of the specimen to permitdescription of the basis onshall be determined by drying to practical equilibrium in accordance with 6.2 which the specific gravityorby calculation (13.1.2 is computed. Test Methods ) in special situations (7.2.4.4D4442 and ).D4444 indicate procedures t

22、hat shouldbe used.7.2.4 Small SpecimensThe entire specimen may be used for determination of moisture content.7.2.4 Intermediate SpecimensMoisture ContentWhen the specimen is of a size that is unsuitable for moisture contentdeterminationsDetermine the moisture content (M (the time to oven-dry to cons

23、tant mass would be excessive), a segment may becut from the specimen for a moisture content specimen. Select this segment so that its moisture content is representative of thatof the larger specimen. Where possible in solid wood elements, the moisture content specimen shall be of full cross-sectiona

24、ldimensions and 1 in. (25 mm) in length (parallel to grain). In sheet materials the specimen shall be equal in thickness to thethickness of the material ) of the specimen to permit description of the basis on which the density or specific gravity is computed.Test Methods D4442 and 3D7438 by 6 in. (7

25、6 by 122 mm) in size.indicate procedures that shall be used.7.2.4.1 Small SpecimensThe entire specimen shall be used for determination of moisture content in accordance with D4442.7.2.4.2 Intermediate SpecimensWhen the specimen is of a size that is unsuitable for moisture content determinations (the

26、 timeto oven-dry to constant mass would be excessive), a segment shall be cut from the specimen in accordance with 6.1 for moisturecontent measurement using methods D4442. Select this segment so that its moisture content is representative of that of the largerspecimen. Where possible in wood element

27、s and structural composite lumber, the moisture content specimen shall be of fullcross-sectional dimensions approximately 1 in. (25 mm) in length (parallel to grain). In sheet materials the specimen shall be equalin thickness to the thickness of the material and 3 by 6 in. (76 by 122 mm) in size.7.2

28、.4.3 Structural ElementsIn full-size members, the moisture content shall be determined on a segment cut from the memberin accordance with 6.1. It shall be of full cross-sectional dimensions and approximately 1 in. (25 mm) in length parallel to grain,and shall be selected from a representative area o

29、f the member (see Note 7).NOTE 7The specimens should be cut in the area of interest. Where possible, avoid the effects of end drying.7.2.4.4 Special SituationsWhere the specimen or element cannot be cut to secure a moisture content segment, an approximatemoisture content shall be obtained through th

30、e use of a moisture meter in accordance with Test Methods D7438 (see Note 8). Theuse of moisture meters shall not be permitted for materials other than wood.NOTE 8Since the moisture content value obtained with moisture meter is approximate, it should be recognized that the specific gravity values ob

31、tainedare approximate.7.2.6 Structural ElementsIn full-sized members, determine the moisture content from a segment cut from the member. It shallbe of full cross-sectional dimensions and 1 in. (25 mm) in length (parallel to grain), and shall be selected from a representativearea of the member. To av

32、oid the effects of end drying, cut the specimen at least 18 in. (457 mm) in from the end of the member.7.2.7 Special SituationsWhere the specimen or element cannot be cut to secure a moisture content segment, an approximatemoisture content may be obtained through the use of a moisture meter which is

33、 used in accordance with the manufacturersrecommendations. Since the moisture content value is approximate, it should be recognized that the specific gravity value obtainedwill also be approximate.7.2.8 Specimen PreparationWhen the moisture content specimen is a portion of the element, remove all lo

34、ose particles fromthe specimen and determine the initial mass (mM) in accordance with 6.2.7.3 DryingOven-dry the moisture content specimen to constant mass in accordance with 6.2, and determine the oven-dry mass(m0).8. TEST METHOD BTest Method BVolumeVOLUME BY WATER IMMERSION by Water Immersion8.1 A

35、pplicability:8.1.1 Type of SpecimenThis procedure is particularly adaptable to specimens of irregular shape or having a rough surface.Limitations on specimen size are based primarily on size of immersion tanks available. In small size specimens, less than 1 cm3in volume, air bubbles adhering to the

36、specimen surface cansurface (see Note 9result in considerable error in volume measurementand thus to the computed specific gravity value. Freshly cut green wood will not absorb appreciable quantities of water during thebrief immersion period.As soon as any drying of the wood has taken place however,

37、 the surface must be sealed before immersionin water or else the volumetric displacement of the wood specimen will be in error in an amount equal to the volume of waterabsorbed by the wood.).NOTE 9Limitations on specimen size are based primarily on size of immersion tanks available. In small size sp

38、ecimens, less than 1 cm3 in volume,air bubbles adhering to the specimen surface can result in considerable error in volume measurement and thus in the computed density or specific gravityD2395 144value. Freshly cut green wood will not absorb appreciable quantities of water during the brief immersion

39、 period. If any drying has taken place, the surfaceof the specimen needs to be sealed before immersion in water or else the volumetric displacement of the specimen will be in error in an amount equalto the volume of water absorbed by the wood.8.2 Procedures:8.2.1 MassInitial mass (mM)Determine the i

40、nitial mass (mM) of the specimen at time of test in accordance with 6.2.8.2.2 VolumeDetermine the volume of the specimen by one of the following modes. Volume may be determined in the asreceived condition if the specimen is green; or in the as received condition if the specimen is partially dry or a

41、fter oven-dryingif the pores are adequately sealed (see 8.2.2.5). Determine the volume of the specimen by measuring the volume of water displacedor by determining or the mass of the water displaced. The mass displaced by the specimen using one of the following modes. Themass of water in grams is num

42、erically equal to theits volume in cubic centimetres.centimeters. Unless the volume is determinedon a specimen of green wood, 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 known volume and add sufficient water to fill the tank. ta

43、nk with the specimenbeing fully submerged. Then remove the specimen and determine the volume of water remaining. The tank volume less the volumeof water remaining is equal to the volume of the specimen. The relationship between specimen volume and tank volume shall besuch that the precision of speci

44、men volume measurement is high.adequate to the purpose of the test.8.2.2.2 Mode IIPlace a container holding enough water to completely submerge the specimen on one pan of a balance asshown in Fig. 1. Then tare the balance to the combined mass of the container and water with mass added to the other p

45、an. Holdthe specimenwater. Using a sharp, pointed, slender rod, place the specimen in the container so that it is completely submerged inthe water without touching the sides of the container by means of a sharp, pointed, slender rod and balance the scales again. Themass added to restore container. A

46、fter reaching the equilibrium, the reading on the balance is equal to the mass of water displacedby the specimen. Alternatively, an automatic balance may be used and will greatly facilitate the speed of such measurements. Ifvery small specimens are used, the accuracy of resulting data is likely to b

47、e low.8.2.2.3 Mode IIIPlace a container holding enough water to completely submerge the specimen below one pan of on a balanceas shown in Fig. 2. The container shall be sufficiently large so that immersion of the specimen causes no materialsignificant changein water level. Suspend a wire basket of s

48、ufficient mass to holdkeep the specimen submerged from this same pan and immerse itin the water. Balance the Tare the balance to the mass of the basket when freely immersed with mass added to the other scale pan.immersed. Weigh the specimen in air. Place the specimen in the basket and hold it comple

49、tely submerged without touching thecontainer while balancing the scales again. The mass added to restorecontainer. After reaching the equilibrium, the mass readingon the balance, if the specimen is lighter than water, plus the mass of the specimen in air equals the volume of water displaced.If the specimen is heavier than water, subtract the mass added to restorereading on the balance from the mass of the specimen inair to determine the volume of water displaced.8.2.2.4 Mode IVImmerse the specimen, of an elongated shape, in a gradua