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

1、Designation: D 3201 08Standard 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 yea

2、r of last revision. 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 This test method prescribes the procedure for determin-ing the moisture content of fire-retardant-treated wood a

3、ndwoodbased product samples after exposure to a standard highrelative humidity condition of 92 6 2 % at 27 6 2C (81 64F).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 becon

4、sidered as requirements of this test method.1.3 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility o

5、f 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 176 Terminology of Fire Standards3. Terminolo

6、gy3.1 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 untreated products. This is particularly true at the

7、higher 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 The results obtained with this standard are

8、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 interior use include requirementsbased on this te

9、st 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 (2176 4F).5.3 Weighing ScaleA scale or balance that will weig

10、h 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 as needed to provide a minimum volume of33 000

11、 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 control specimens is highly recom-mended not only to supply useful data on the relative influence oftreatments, but also to provide relative inform

12、ation on the high-humidityconditions used.7. Procedure7.1 All measurements of the specimen weight shall be to anaccuracy of 60.2 %.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 editi

13、on approved Feb. 1, 2008. Published February 2008. Originallyapproved in 1973. Last previous edition approved in 2007 as D 3201 07.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume informa

14、tion, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.7.2 The specimens shall be in moisture equilibrium with alaboratory ambient condition of 30 to 65 % relative humidi

15、ty orshall be exposed for at least 7 days 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

16、 the seven days.7.4 Weigh each specimen 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 seven days.Specimens shall be suitably suspended so that all surfaces areexposed.7.6 If the specimens exude moistu

17、re or chemicals or bothunder the exposure conditions, 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

18、 the specimens.7.8 Dry each specimen in an oven at 103 6 2C (217 64F) until approximately constant weight is attained, andreweigh to obtain ovendry weight after high humidity expo-sure. Constant weight can be assumed when two consecutivereadings taken 2 h apart agree within 0.2 %. Avoid drying forpe

19、riods longer than necessary to achieve constant weight, sincethermal 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

20、)where:mi= weight of specimen prior to high-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

21、expo-sure, andmod= ovendry weight of specimen after high-humidityexposure.8.3 When data are available for untreated specimens ex-posed under identical conditions of high-humidity exposure,the change in the moisture content of the specimens shall becalculated as the difference between the average moi

22、sturecontents for the treated and untreated specimens as calculatedin 8.2.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

23、content is relative to the total specimen weight 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 spec

24、imen.9. Report9.1 Report the following information: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 contro

25、lsused for the test.9.1.4 When data are available for untreated specimensexposed simultaneously with the treated specimens to thehigh-humidity condition, the report shall include the averagemoisture content of the untreated specimens and the change inthe average moisture content after high-humidity

26、exposurecompared to the moisture content of untreated specimens.9.1.5 The average of the moisture contents for the treatedspecimens before high-humidity exposure, as calculated by Eq1, shall be reported.9.1.6 The average of the moisture contents for the treatedspecimens after high-humidity exposure,

27、 as calculated by Eq 2,shall be reported.9.1.7 Report any change in the appearance of the specimenduring exposure, including surface wetness, chemical exuda-tion, or crystals on surface.10. Precision and Bias10.1 There is insufficient data available to write a precisionand bias statement.11. Keyword

28、s11.1 fire-retardant treated wood; hygroscopicity; moisturecontentD3201082ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity

29、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 reviewed every five years andif not revised, either reapproved or withdrawn. Your comments

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31、eceived 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).D3201083