ASTM D5664-2008 317 Standard Test Method for Evaluating the Effects of Fire-Retardant Treatments and Elevated Temperatures on Strength Properties of Fire-Retardant Treated Lumber.pdf

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1、Designation: D 5664 08Standard Test Method forEvaluating the Effects of Fire-Retardant Treatments andElevated Temperatures on Strength Properties of Fire-Retardant Treated Lumber1This standard is issued under the fixed designation D 5664; the number immediately following the designation indicates th

2、e year oforiginal adoption or, in the case of 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.1. Scope1.1 This test method covers procedures for obtaining d

3、ata toassess the initial adjustments to allowable design stresses forlumber treated with candidate commercial fire-retardant (FR)formulations and further procedures for obtaining data toassess the effect of extended exposure to elevated temperatureof 66 6 2C (150 6 4F).1.2 This standard does not pur

4、port to address all of thesafety concerns, if any, associated 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

5、 Terminology Relating to Wood and Wood-Based Prod-uctsD 143 Test Methods for Small Clear Specimens of TimberD 1165 Nomenclature of Commercial Hardwoods and Soft-woodsD 3500 Test Methods for Structural Panels in TensionD 4761 Test Methods for Mechanical Properties of Lumberand Wood-Base Structural Ma

6、terialD 5516 Test Method for Evaluating the Flexural Propertiesof Fire-Retardant Treated Softwood Plywood Exposed toElevated TemperaturesE84 Test Method for Surface Burning Characteristics ofBuilding MaterialsE 176 Terminology of Fire Standards2.2 Other Standards:AWPA C20 LumberFire Retardant Treatm

7、ent by PressureProcesses3NFPA 703 Standard for Fire Retardant Impregnated Woodand Fire Retardant Coatings for Building Materials4U.S. Product Standards PS 20 American Softwood LumberStandard53. Terminology3.1 DefinitionsDefinitions used in this test method are inaccordance with Terminologies D9and E

8、 176 and Nomencla-ture D 1165.4. Summary of Test Method4.1 The general objectives of this test method are to developdata to adjust allowable design stresses of FR-treated lumberfor the initial effects for the tested FR-formulation(s) and todevelop data on in-service thermal stability after extendede

9、xposure to environmental conditions up to 66 6 2C (150 64F) and $50 % relative humidity.4.2 Procedure 1This procedure uses small clear speci-mens cut from end-matched nominal 2 by 4 (38 by 89-mm)dimension lumber (see Fig. 1) to compare the initial effects offire-retardant treatments to untreated con

10、trols for bending,tension parallel, compression parallel, and horizontal shearproperties.4.3 Procedure 2This procedure uses small clear speci-mens cut from end matched nominal 2 by 4 (38 by 89-mm)dimension lumber. This second set of specimens is used toassess the differential trends between end-matc

11、hed fire-retardant treated and untreated specimens on bending andtension parallel properties over the course of a prolongedexposure to elevated temperature.1This test method is under the jurisdiction of ASTM Committee D07 on Woodand is the direct responsibility of Subcommittee D07.07 on Fire Perform

12、ance ofWood.Current edition approved Aug. 1, 2008. Published September 2008. Originallyapproved in 1995. Last previous edition approved in 2002 as D 5664 02.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of AS

13、TMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from American Wood Protection Association (AWPA), P.O. Box361784, Birmingham, AL 35236-1784, http:/.4Available from National Fire Protection Association (NFPA), 1 BatterymarchPark, Quincy, MA 0

14、2169-7471, http:/www.nfpa.org.5Available from American Lumber Standard Committee, Incorporated (ALSC),P.O. Box 210, Germantown, MD 20875-0210, http:/www.alsc.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4.4 Procedure 3The opti

15、onal third procedure uses full-sized nominal 2 by 4 (38 by 89-mm) dimension lumber tomodify the small clear specimen results from 4.2 and 4.3 forsize effects.5. Significance and Use5.1 The mechanical properties evaluated by this test methodprovide the following:5.1.1 Data for use in developing modif

16、ication factors for theallowable design properties of fire-retardant treated lumberwhen used at or near room temperatures (see 6.3).5.1.2 Data for use in developing modification factors forallowable design properties of fire-retardant treated lumberwhen exposed to elevated temperatures and humidity

17、(see 6.4).5.1.3 Data (optional) for use in modifying these factors forsize effects when fire-retardant treated lumber is used at or nearroom temperature and when exposed to elevated temperaturesand humidity (see 6.5).5.2 Data from the first two procedures in this test method ofevaluation are indicat

18、ive only for that species.NOTE 1The results of the three listed species (Southern pine, Douglasfir, and either white spruce or a Spruce/Fir mixture) may be used togetherto make inference on untested wood species because the three testedspecies represent the full spectrum of expected treatability.5.3

19、 Data from the optional third part of this three-partmethod of evaluation are indicative for all species because it isprimarily used to assess size effects.6. Procedures6.1 Treatment:6.1.1 Pressure treat those pieces designated for treatmentwith the fire-retardant formulation being evaluated. The ga

20、geretention level of each charge shall not be less than themidpoint of the retention range as specified for the species bythe agency certifying the flame spread index of the treatedlumber. The retention range specified by the certifying agencyshall provide a flame-spread index of 25 or less when tes

21、ted inaccordance with Test Method E84 for 10 min, show noevidence of significant progression combustion when the test iscontinued for an additional 20-min period and not allowprogression of the flame front beyond a distance of 3.2 m (10.5ft) beyond the centerline of the burners anytime during the30-

22、min extended test.6.1.1.1 The provisions of 6.1.1 are not intended to preventuse of this test standard when the fire-retardant treatmentsbeing certified are for applications other than those requiringconformance to AWPA C20, NFPA 703, or similar buildingcode requirements for “fire-retardant-treated

23、wood” that re-quire the Test Method E84test extended to 30 min. Whenalternative performance criteria for the treatment are beingcertified, the test report on specimens of that treatment shallstate clearly the alternative performance criteria and that thetreatment retention was limited to that requir

24、ed for the alter-native performance criteria.6.1.2 Weigh all treated pieces before and immediately aftertreatment to determine the chemical retention based on thesolution retained and the concentration of chemicals in thesolution. Complete a treating report for each charge of materialto document the

25、 treating cycle, times, pressures, gage retention,and piece retentions.6.2 Post-Treatment Drying:6.2.1 After pressure treatment, kiln dry the treated pieces toa maximum moisture content of 19 % following the standardredrying procedures established for the treatment and speciesby the manufacturer. Re

26、dry the treated pieces at the manufac-turers maximum specified dry bulb temperature with a minus2C (4F) tolerance for 21 h of the first 24-h period. For theremainder of the drying period, the tolerance shall be minus3C (5F). There is no upper limit on the redrying temperature.Sticker all test pieces

27、 to obtain proper air flow across bothsurfaces and to provide even drying.NOTE 2Research has shown that high kiln drying temperatures canadversely affect the structural properties of wood products. TheAWPAandNFPAstandards for fire retardant treated wood products limit kiln dry bulbtemperatures. AWPA

28、 C20 requires that the dry bulb temperature of thekiln not exceed 70C (160F) during any kiln drying of plywood treatedwith fire retardants. In the case of exterior fire-retardants that requirecuring at higher temperatures, curing after the moisture content is 19 % orless is permitted. However, such

29、elevated curing temperatures must notexceed 99C (210F) and the total curing time must not exceed 48 h. InNFPA 703, the dry bulb temperature must not exceed 70C (160F) untilthe average moisture content of the wood has dropped to 25 % or less.NOTE 3To establish the worst-case strength properties of tr

30、eatedlumber, the laboratory must redry the test material within a small negativetolerance of the maximum temperature used by the manufacturer. There-fore, there is no upper limit for the temperature used in the tests. If amanufacturer desires to establish conservative property values or providea bas

31、is for evaluating production material that exceeds the limit, the testFIG. 1 Hypothetical Cutting Patterns to Obtain One Bending, TwoTension Parallel, One Compression Parallel, One Block Shear,and One Specific Gravity Block from Each 1.2-m (4-ft) LumberSpecimenD5664082material can be redried at that

32、 temperature.Amanufacturer then is allowedto determine the necessary production schedule for their treatment andequipment or conditions. Thus, a stepped schedule (for example, 10 h at54C (130F), 10 h at 60C (140F); 10 h at 71C (160F), etc.) is allowedby the standard, provided the maximum temperature

33、 tolerance require-ment is met. These provisions provide for air-drying production materialprovided the redry conditions in the tests are within the tolerance of themaximum temperature specified by the manufacturer.6.2.2 Monitor the moisture content of the test pieces duringthe drying cycle by indiv

34、idually weighing representativepieces. Keep a well-documented kiln charge report and kilnrecorder chart showing dry and wet bulb temperatures duringthe redrying period.6.3 Procedure 1The first procedure presents a methodol-ogy using small clear wood specimens to assess the initialeffect of fire-reta

35、rdant treatment on median mechanical prop-erties. The results may be used to adjust the allowable designstresses of lumber based on estimates of median reductions inbending, tension parallel, compression parallel, and horizontalshear properties using small clear specimens cut from largerend-matched

36、dimension lumber specimens.6.3.1 For each species/species grouping (Southern pine,Douglas fir, and either white spruce or a Spruce/Fir mixture),twenty five (25) 2.44m (8ft) long, high-grade nominal 2 by4s (38 by 89 mm) shall be obtained and cut into 1.22-m (4-ft)halves. Each specimen shall be marked

37、 to identify it with itsmatched-sister(s) specimen(s). For each specimen, one 1.22-m(4ft) half shall be randomly allotted to remain untreated andthe other half assigned to be treated with the candidatefire-retardant treatment and each half shall be appropriatelymarked.NOTE 4A Spruce/Fir mixture can

38、be obtained by obtaining CanadianSpruce-Pine-Fir and removing the Lodgepole pine and Jack pine, whichcan be visually segregated from the remaining spruces and firs of thisspecific species group. The Lodgepole pine and Jack pine have numerouslongitudinal resin canals that are generally quite evenly d

39、istributed in theouter portion of every growth ring. In the four spruces (Black, Engelmann,Red, and White), the longitudinal resin canals are generally sparse. In thetwo firs (Alpine and Balsam), the longitudinal resin canals are normallyabsent.NOTE 5High Grade is a relative term, but some latitude

40、is requiredbecause it is a common industry practice to group grades for somespecies/species groupings into “and better” categories. If available, SelectStructural often is desirable because it provides an adequate yield of smallclear specimens. It should also be noted that initial use of $30 specime

41、nswill usually ensure 25 acceptable specimens when using lower gradeswhich have lower yields.6.3.2 After treating and redrying are completed, each treatedand untreated nominal 2 by 4 (38 by 89-mm) piece shall be cutinto small clear specimens as shown in Fig. 1. Care shall betaken to avoid cutting sp

42、ecimens containing strength-reducingcharacteristics such as knots, cross-grain, or slope-of-grain inexcess of 1 in 12. When cutting small test specimens, anoriginal wide surface shall remain unmachined and eachspecimen shall later be tested so that this surface is exposed tothe greater stress during

43、 that particular mechanical test. Eachend-matched treated and untreated specimen shall be testedwith the same relative surfaces in tension and compression.Tension parallel specimens shall be machined as shown in Fig.2. Horizontal shear specimens shall be machined as shown inFig. 3.6.3.3 After cuttin

44、g, all specimens (treated and untreated)shall be equilibrated to constant weight at 22 + 5C (72 + 9F)and65+1%relative humidity.6.3.4 Appropriate treated and untreated specimens shall bealternately tested in bending, compression parallel, and hori-zontal shear using Test Methods D 143 and tension par

45、allelusing Test Methods D 3500, but with the exceptions listed inTable 1.6.4 Procedure 2For each species (Southern pine, Douglasfir and white spruce, four sets of 25 end-matched treated anduntreated small clear bending and tension parallel specimensshall be cut from at least 25 nominal 2 by 4 (38 by

46、 89 mm)2.44-m (8-ft) long pieces. These specimens shall be used toassess the differential effects of exposure to elevated tempera-ture between untreated and FR-treated clear wood specimens.6.4.1 One set of 25 FR-treated and untreated specimens ofeach species shall be used as an unexposed control (th

47、at is, 0days of exposure).6.4.2 Three FR-treated and untreated groups of 25 speci-mens of each species shall be exposed in a controlled environ-ment of 66 + 2C (150 + 4F) and 50 % relative humidity.6.4.3 One treated and one untreated group of 25 shall bewithdrawn after 36 +3, 72 +3, and 108 +3 days.

48、FIG. 2 Dimensions of the Modified Tension Parallel to GrainSpecimen Using Test Methods D 3500D56640836.4.4 Each group of specimens shall be equilibrated toconstant weight at 22 + 5C (72 + 9F) and 65+1%relativehumidity then tested in bending in accordance with TestMethods D 143 and tension parallel i

49、n accordance with TestMethods D 3500, but with the exceptions listed in Table 1.6.5 Procedure 3The optional third procedure expands theresults of the small clear results obtained in 6.3 and 6.4 toinclude additional information on size effects. It assesses boththe initial effects of fire-retardant treatments on the allowabledesign stresses of lumber and the potential for additionalstrength loss after extended exposure to elevated temperatures.To address the former, bending properties shall be assessedusing matched FR-treated a