ASTM D2898-2008e1 Standard Practice for Accelerated Weathering of Fire-Retardant-Treated Wood for Fire Testing.pdf

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1、Designation: D 2898 081Standard Practice forAccelerated Weathering of Fire-Retardant-Treated Wood forFire Testing1This standard is issued under the fixed designation D 2898; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year

2、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.1NOTEMathematical conversion errors were editorially corrected throughout in March 2009.1. Scope1.1 This practice covers the du

3、rability of a fire-retardanttreatment of wood under exposure to accelerated weathering.Four conditioning methods are described. Methods are suitablefor application to a test specimen prior to subjecting thatspecimen to an appropriate fire test.1.2 This practice is applicable to wood products that ha

4、vebeen treated with fire-retardant chemicals by pressure impreg-nation.1.3 The test specimens are to be in the form of, or suitablefor fabrication into, test specimens, such as those described inTest Methods E84, E 108, and E 1354 and other standard testmethods for evaluating the fire performance of

5、 fire-retardant-treated wood products.1.4 The text of these methods references notes and footnotesthat provide explanatory material. These notes and footnotes(excluding those in tables and figures) shall not be consideredas requirements of these test methods.1.5 The values stated in inch-pound units

6、 are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.6 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibil

7、ity 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-uctsE84 Test Method for Surface Burning Charac

8、teristics ofBuilding MaterialsE 108 Test Methods for Fire Tests of Roof CoveringsE 176 Terminology of Fire StandardsE 1354 Test Method for Heat and Visible Smoke ReleaseRates for Materials and Products Using an Oxygen Con-sumption Calorimeter2.2 ICC Evaluation Service Acceptance Criteria:3AC 107 Cla

9、ssified Wood Roof Systems2.3 UL Standards:4UL 790 Tests for Fire Resistance of Roof Covering Material3. Terminology3.1 DefinitionsDefinition used in this practice are inaccordance with Terminologies D9and E 176, unless other-wise indicated.4. Significance and Use4.1 This practice describes different

10、 methods of exposingfire-retardant-treated wood products or assemblies to con-trolled accelerated weathering or conditioning.4.2 The conditioning simulates effects of leaching, drying,temperature, and, in two methods, ultraviolet (UV) light.4.3 Method A is the method normally specified for regula-to

11、ry purposes when testing fire-retardant-treated wood that isintended for exterior applications.5. Apparatus5.1 The test apparatus shall be capable of subjecting thespecimen uniformly to the test conditions described in Section7.5.2 No special means of protecting the specimen back andedges are requir

12、ed, but water shall not impinge directly onthose surfaces which are not exposed either to the weather inthe assembled form, or to fire in the subsequent test. Waterspray nozzles shall be provided and arranged so as to distributewater evenly over the exposed specimen surface.1These test methods are u

13、nder the jurisdiction of ASTM Committee D07 onWood and are the direct responsibility of Subcommittee D07.07 on Fire Perfor-mance of Wood.Current edition approved Nov. 1, 2008. Published December 2008. Originallyapproved in 1970. Last previous edition approved in 2007 as D 2898 07.2For referenced AST

14、M 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.3Available from ICC Evaluation Service, Inc., 5360 Workman Mill Road,Whittier, C

15、A 90601, http:/icc-es.org.4Available from Underwriters Laboratories, Inc., 333 Pfingsten Road, North-brook, IL 60062, http:/.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.3 Accompany drying cycles with heating that is thermo-stat

16、ically controlled. The controlling temperature shall be theair temperature measured 1 in. (25 mm) above the specimensurface. When sunlamps are part of the method, thetemperature-measuring device must be shielded from the UVradiation of the sunlamps. Accompany drying with uniformforced air movement a

17、cross the surface of the decks at a rate ofat least 25 ft/min (0.127 m/s). Forced air movement shall beuniform across the specimen surface, with provisions made foradequate air changes to assure thorough drying.5.4 In Methods B and C, UV light shall be distributed asevenly as possible over the speci

18、men surface. Use sunlamps5providing UV characteristics of 5.0 W/m2/nm irradiance at awavelength of 315 to 400 nm at 1 m directed normal to andmounted 26 6 6 in. (660 6 152 mm) above the specimenmeasured from the bottom of the lamp. One lamp shall be usedfor each 8 ft2(0.74 m2) of specimen, or fracti

19、on thereof.5.5 Water Spray Calibrations:5.5.1 Measure the horizontal projected area over which eachnozzle discharges water to the nearest square foot (0.09 m2).Measure the discharge of water for each nozzle for 1 min.5.5.2 Monitor the total water use during the test. A commer-cial water meter is sui

20、table for this purpose.5.5.2.1 For Method A, the water usage shall be 42 6 1gal/ft2(1711 6 41 L/m2) for a four-day cycle or 73 6 1.7gal/ft2(2975 6 69 L/m2) for a seven-day cycle.5.5.3 Each day during the water cycle, visually check thewater flow from each nozzle for obvious water obstruction inthe n

21、ozzle and uneven spray patterns. Make adjustments whennecessary.5.5.4 Review the total water flow at the end of each day andat the end of each water cycle. Correct the cause of anyoff-limit conditions.5.5.5 The characteristics or quality of the water shall benoted (see Note 1).NOTE 1Note water quali

22、ty, especially pH and hardness, as it canimpact the accelerated weathering of the treated specimens.6. Test Specimen6.1 The test specimen shall include all parts of the corre-sponding fire test specimen that are subjected to weatherexposure in normal use. Shingles or shakes shall be applied totheir

23、intended sheathing.NOTE 2It is acceptable to mount specimens in sections that can bereassembled subsequently without trimming into the appropriate fire testspecimen.6.2 The specimen surface shall have a slope of 4 in 12 inMethods A, C, and D of this standard. For Method B, thesurface shall have a sl

24、ope ranging from 4 in 12 minimum to 8in 12 maximum.7. Exposure Cycle7.1 Method A:7.1.1 The total duration of this method is twelve weeks (84days).7.1.2 Subject the specimens to an exposure cycle consistingof twelve one-week cycles. Each cycle is to consist of 96 h (4days) of water exposure and 72 h

25、(3 days) of drying.7.1.3 Apply water in a moderately fine spray uniformly overthe exposed specimen surfaces by spray nozzles that deliver anaverage of 0.7 in. of water per hour (0.005 mm/s) or 0.0073gal/minft2(0.30 L/minm2) of specimen surface) at a tempera-ture between 35 and 60F (2 and 16C).7.1.3.

26、1 Recirculation of the water is not permitted.7.1.3.2 For decks intended for testing by Test MethodsE 108, nozzles shall be mounted approximately seven feet (2.1m) above the test decks.7.1.4 Dry at a thermostatically controlled temperature of135 to 140F (57 to 60C).7.1.5 At the end of each cycle, ch

27、ange the position of eachspecimen within the apparatus so that each specimen orsegment occupies approximately an equal number of cycles ineach location used.7.2 Method B:7.2.1 The total duration of this method is 1000 h (41 days,16 h).7.2.2 Subject the specimen to a exposure cycle consisting offorty

28、-two 24-h cycles. Each cycle is to consist of 4 h wetting,4 h drying, 4 h wetting, 4 h drying, and 8 h rest. The last cycleis terminated without the 8-h rest period.7.2.3 Apply water in a moderately fine spray uniformly overthe exposed specimen surface at a rate of 0.3 6 0.02 gal/minft2(12.2 6 0.8 L

29、/minm2) of specimen surface. Thetemperature shall not exceed 90F (32C). During the firstthree cycles, drain all water rather than recirculate it. In eachsubsequent wetting period, circulate a volume of at least 5 gal(19 L) of fresh water through each spray head.7.2.4 Dry at a temperature of 150 6 5F

30、 (66 6 3C), withthis temperature attained within 15 min from the start ofdrying. Exposure to the UV sunlamps shall be continuousthroughout the drying period.7.2.5 At the end of one or more cycles, change the positionof the specimens within the apparatus so that each specimen orsegment occupies appro

31、ximately an equal number of cycles ineach location used.7.3 Method C:7.3.1 The total duration of this method is twelve weeks (84days).7.3.2 Subject the specimens to an exposure consisting of252 eight-hour cycles. Each cycle consists of four hours ofwater exposure, followed by four hours of drying.7.

32、3.3 For the water exposure, use spray nozzles that deliveran average of 0.3 6 0.02 gal/min/ft2(12.2 6 0.8 L/min/m2)ata temperature of 35 to 90F (1.6 to 32.2C) to apply theuniformly distributed water exposure.7.3.3.1 For decks intended for testing by Test MethodsE 108, nozzles shall be mounted approx

33、imately two feet abovethe test decks.7.3.3.2 Recirculation of the water is permitted with thefollowing restrictions. At the end of each of the first threewetting cycles, and before each of last three wetting cycles, allwater shall be drained from the system and replaced with freshwater. For all othe

34、r wetting cycles, fresh water shall be5General Electric Type H275 RUV (275 W) or Osram Ultra-Vitalox (300 W), orequivalent, is suitable. General Electric no longer manufactures the Type H275 bulb.D28980812introduced at a rate that provides a minimum of 5 gal (19 L) offresh water per nozzle, per cycl

35、e.7.3.4 Drying shall utilize sunlamps for both heat and UVexposure, with supplemental heaters as required to maintain atemperature of 145F to 155F (63C to 68C) with thistemperature attained within 15 min from the start of drying.7.4 Method D:7.4.1 The total duration of this method is 97 days.7.4.2 S

36、ubject the specimens to an exposure consisting ofseven two-week cycles. Each cycle is to consist of 168 h (sevendays) of water exposure, 48 h (two days) of rest for drainingand 120 h (five days) of drying. The water exposure of theseventh cycle is six days.7.4.3 Apply water in a moderating fine spra

37、y uniformly overthe exposed specimen surfaces by spray nozzles that deliver anaverage of 0.7 in. of water per hour (0.005 mm/s) or 0.0073gal/min-ft2(0.30 L/min-m2) of specimen surface at a tempera-ture between 35 and 60F (2 and 16C).7.4.3.1 Recirculation of the water is not permitted.7.4.3.2 For dec

38、ks intended for testing by Test MethodsE 108, nozzles shall be mounted approximately seven feet (2.1m) above the test decks.7.4.4 Dry at a thermostatically controlled temperature of135 to 140F (57 to 60C).7.4.5 At the end of each cycle, change the position of eachspecimen within the apparatus so tha

39、t each specimen orsegment occupies approximately an equal number of cycles ineach location used.8. Conditioning8.1 Upon completion of the prescribed exposure, the speci-men shall be conditioned in accordance with the applicable firetest standard.8.2 For decks intended for testing by Test Methods E 1

40、08,control the final drying cycle temperature so the moisturecontent of the deck lumber is from 8 % to 12 %. For plywooddeck, the moisture content shall not exceed 8 %.9. Keywords9.1 fire retardant; fire retardant-treated wood; fire testing;weatheringAPPENDIX(Nonmandatory Information)X1. COMMENTARYX

41、1.1 Method A was devised for larger specimens, andMethod B for smaller ones.X1.2 Method B was developed by the USDA, ForestService, Forest Products Laboratory. The method and theexposure chamber commonly associated with Method B aredescribed in various publications of that laboratory.X1.3 A research

42、 study showed that the two exposuremethods, A and B, were equivalent in leaching effect asdemonstrated by the flame-spread results obtained on speci-mens exposed by either method when tested for flame spread.6X1.4 Method C is part of the acceptance criteria forclassified wood roof systems of the ICC

43、 Evaluation Service.The option of successful fire tests after the exposure of the“amended rain test” was developed as an alternative to theirrequirement for successful fire tests of specimens exposed tothe rain test of Method A of this standard and additionalspecimens subjected to three years of the

44、 natural weatheringtests described in the fire test standard for roof coverings(UL 790 and Test Methods E 108).X1.5 Method D is an alternative test cycle for the Rain Testspecified in Test Methods E 108.X1.6 This practice discusses methods for acceleratedweathering of fire-retardant-treated wood for

45、 fire testing. InTest Methods E 108 and in AC 107, such accelerated methodsare referred to as “rain” tests. The term “weathering” refers toexposing the specimens to actual outdoor exposures for speci-fied periods of time. For the outdoor exposures, the test decksare mounted facing south at an inclin

46、e of 0.5 in. per horizontalfoot (416 mm per horizontal metre). Decks are tested after eachof one, three, five, and ten years of exposure.6“Correlation of ASTM Exposure Tests for Evaluating Durability of Fire-Retardant Treatment of Wood,” by C.A. Holmes, Forest Products Laboratory,Research Paper FPL

47、194, U.S.D.A. Forest Service, 1973.D28980813ASTM 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 of any such patent rights, and

48、 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 are invited either for revisio

49、n of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will 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 International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (si