ASTM D3201-2008a Standard Test Method for Hygroscopic Properties of Fire-Retardant Wood and Wood-Based Products.pdf

1、Designation: D 3201 08aStandard Test Method forHygroscopic Properties of Fire-Retardant Wood and Wood-Based Products1This standard is issued under the fixed designation D 3201; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the ye

2、ar 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.1. Scope1.1 This test method prescribes the procedure for determin-ing the moisture content of fire-retardant-treated wood a

3、ndwood-based product samples after exposure to a standard highrelative humidity condition of 92 6 2 % at 27 6 2C(81 6 4F).1.2 The text of this test method references notes andfootnotes which provide explanatory material. These notes andfootnotes (excluding those in tables and figures) shall not beco

4、nsidered as requirements of this test method.1.3 The values stated in SI units are to be regarded as thestandard. The inch-pound values given in parentheses are forinformation only and are not considered standard.1.4 This standard does not purport to address all of thesafety concerns, if any, associ

5、ated 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 Relating to Wood and Wood-Based Prod-uctsE 1

6、76 Terminology of Fire Standards3. Terminology3.1 DefinitionsDefinitions used in this practice are inaccordance with Terminologies D9and E 176.4. Significance and Use4.1 The hygroscopic properties of wood and wood-basedproducts treated with fire-retardant chemicals are often greaterthan for untreate

7、d products. This is particularly true at thehigher relative humidity conditions. This higher hygroscopicitysometimes is the cause for staining, decay, poor paint adhesion,and migration and exuding of chemicals and moisture at thehigh humidities. Corrosion of metal fasteners sometimes alsooccurs.4.2

8、The results obtained with this standard are important inidentifying treatments with low hygroscopic properties.4.3 Results can be useful in determining exposure limita-tions in service for specific treated products.4.4 Building codes and other specifications for fire-retardant-treated wood for inter

9、ior use include requirementsbased on this test method.5. Apparatus5.1 Conditioning chamber with air circulation and capableof being maintained at 27 6 2C (81 6 4F) and a relativehumidity of 92 6 2%.5.2 Oven, air-circulated and vented, capable of maintaininga temperature of 103 6 2C (217 6 4F).5.3 We

10、ighing ScaleA scale or balance that will weigh aspecimen within an accuracy of 60.2 %.6. Test Specimens6.1 A minimum of five specimens shall be selected thatrepresent the lot. Unless otherwise specified, specimens shallbe full cross sections, no less than 25.4 mm (1 in.) along thegrain, but longer a

11、s needed to provide a minimum volume of33 000 mm3(2 in.3).6.2 The specimens shall be penetrated by the fire-retardantchemical to be representative for the treated product.NOTE 1The use of untreated specimens as control specimens isrecommended to provide verification of the high-humidity conditionsus

12、ed.1This test method is under the jurisdiction of ASTM Committee D07 on Woodand is the direct responsibility of Subcommittee D07.07 on Fire Performance ofWood.Current edition approved Nov. 1, 2008. Published December 2008. Originallyapproved in 1973. Last previous edition approved in 2008 as D 3201

13、08.2For 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.1Copyright ASTM International, 100 Barr Harbor Drive, PO B

14、ox C700, West Conshohocken, PA 19428-2959, United States.7. Procedure7.1 All measurements of the specimen weight shall be to anaccuracy of 60.2 %.7.2 The specimens shall be in moisture equilibrium with alaboratory ambient condition of 30 to 65 % relative humidity orshall be exposed for at least 7 da

15、ys at such a condition prior tohigh-humidity exposure.7.3 If the specimens will support fungal or mold growthduring the high humidity exposure, then the specimens shall besprayed with a suitable biocide just prior to the above exposureand allowed to air-dry for the seven days.7.4 Weigh each specimen

16、 to obtain weight prior to highhumidity exposure.7.5 Expose all specimens under constant humidity condi-tions of 92 6 2 % at 27 6 2C (81 6 4F) for 7 days.Specimens shall be suitably suspended so that all surfaces areexposed.7.6 If the specimens exude moisture or chemicals or bothunder the exposure c

17、onditions, collect any drippings andinclude the weight with the specimen weight.7.7 Weigh each specimen immediately, after its removalfrom the conditioning chamber to obtain the weight after highhumidity exposure. Observe and record the general appearanceof the specimens.7.8 Dry each specimen in an

18、oven at 103 6 2C(217 6 4F) until approximately constant weight is attained,and reweigh to obtain ovendry weight after high humidityexposure. Constant weight can be assumed when two consecu-tive readings taken 2 h apart agree within 0.2 %. Avoid dryingfor periods longer than necessary to achieve cons

19、tant weight,since thermal decomposition of chemical or wood might occurreflecting a higher than actual moisture content.8. Calculations8.1 Calculate the moisture content of each specimen prior tohigh-humidity exposure (ui) as follows:ui,%5mi modmod!3 100 (1)where:mi= weight of specimen prior to high

20、-humidity expo-sure, andmod= ovendry weight of specimen after high-humidityexposure.8.2 Calculate the moisture content of each specimen afterhigh-humidity exposure (uf) as follows:uf,%5mf modmod!3 100 (2)where:mf= weight of the specimen after high-humidity expo-sure, andmod= ovendry weight of specim

21、en after high-humidityexposure.NOTE 2These methods of determining the moisture content do notcorrect for any volatilization of chemical during the ovendrying, whichincreases the calculated percent moisture content. Also, the calculation forpercent moisture content is relative to the total specimen w

22、eight of woodand chemical. The percent moisture content relative to the wood weightalone is higher and this value can be estimated by reducing the modvaluein the divisor of the above equation by the known or assumed percentageof chemical in the treated specimen.9. Report9.1 Report the following info

23、rmation:9.1.1 Complete identification of the fire-retardant product asto species of wood, wood product, and treatment.9.1.2 Description of sampling procedure and number anddimensions of test specimens.9.1.3 General description of humidity chamber and controlsused for the test.9.1.4 When data are ava

24、ilable for untreated specimensexposed simultaneously with the treated specimens to thehigh-humidity condition, the report shall include the averagemoisture content of the untreated specimens at the end of theexposure.9.1.5 The average of the moisture contents for the treatedspecimens before high-hum

25、idity exposure, as calculated by Eq1, shall be reported.9.1.6 The average of the moisture contents for the treatedspecimens after high-humidity exposure, as calculated by Eq 2,shall be reported.9.1.7 Report any change in the appearance of the specimenduring exposure, including surface wetness, chemi

26、cal exuda-tion, or crystals on surface.10. Precision and Bias10.1 There is insufficient data available to write a precisionand bias statement.11. Keywords11.1 fire-retardant treated wood; hygroscopicity; moisturecontentASTM International takes no position respecting the validity of any patent rights

27、 asserted in connection with any item mentionedin this standard. 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 ti

28、me by the responsible technical committee and must be reviewed 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

29、receive careful consideration at a meeting of theresponsible 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

30、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 3201 08a2