ASTM D3201-2007 Standard Test Method for Hygroscopic Properties of Fire-Retardant Wood and Wood-Based Products《防火木材和木制品吸湿特性的标准试验方法》.pdf

1、Designation: D 3201 07Standard 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.6.3 Untreated specimens, when available, of the same spe-cies or wood-based product and of the same size, shall beexposed to the preconditioning, high-humidity exposure, andd

12、rying along with the treated specimens.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 April 15, 2007. Published May 2007. Originallyapproved in 1973. Last previous ed

13、ition approved in 2003 as D 3201 94 (2003).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 In

14、ternational, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.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 information on the high-humiditycon

15、ditions used.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 days at such a condition prior tohigh-humidity

16、 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 to obtain weight prior to highhumidity expo

17、sure.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 moisture or chemicals or bothunder the exposure conditions, collect any drippings andincl

18、ude 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 oven at 103 6 2C (217 64F) until approxi

19、mately 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 forperiods longer than necessary to achieve constant weight, sincethermal decomposition

20、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-humidity expo-sure, andmod= ovendry wei

21、ght 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 specimen after high-humidityexposure.8.3 When

22、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 moisturecontents for the treated and untreated specimens as calculatedin 8.2.NOTE 2The

23、se 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 weight of woodand chemical. The percent m

24、oisture 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 information:9.1.1 Complete identification of

25、 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 available for untreated specimensexposed si

26、multaneously 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 exposurecompared to the moisture content of untreated specimens.9.1.5 The average o

27、f 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, as calculated by Eq 2,shall be reported.9.1.7 Report any change in the appearance

28、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. Keywords11.1 fire-retardant treated wood; hygroscopicity; moisturecontentD3201072ASTM Inte

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32、ndards, 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).D3201073