1、Designation: D2898 10 (Reapproved 2017)Standard Practice forAccelerated Weathering of Fire-Retardant-Treated Wood forFire Testing1This standard is issued under the fixed designation D2898; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revi
2、sion, 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 practice addresses the durability of a fire-retardanttreatment of wood products by exposure to
3、accelerated cyclesof wetting, drying, or ultraviolet (UV) exposure, or combina-tion thereof, prior to evaluation by a fire response test. Fourconditioning methods are described.1.2 This practice is applicable to wood products that havebeen treated with fire-retardant chemicals by pressure impreg-nat
4、ion.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, E108, and E1354 and other standard testmethods for evaluating the fire performance of fire-retardant-treated wood products.1.4 The text of these methods r
5、eferences 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 are to be regardedas standard. The values given in parentheses are m
6、athematicalconversions 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 theresponsibility of the user of this standard to establish appro-priate safety and
7、 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 Characteristics ofBuilding MaterialsE108 Test Methods for Fire Tests of Roo
8、f CoveringsE176 Terminology of Fire StandardsE1354 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 Classified Wood Roof Systems2.3 UL Standards:4UL 790 Tests for Fire Resista
9、nce of Roof Covering Material3. Terminology3.1 DefinitionsDefinition used in this practice are inaccordance with Terminologies D9 and E176, unless otherwiseindicated.4. Significance and Use4.1 This practice describes different methods of exposingfire-retardant-treated wood products or assemblies to
10、con-trolled accelerated weathering or conditioning.4.2 The conditioning simulates effects of leaching, drying,temperature, and, in two methods, UV light.4.3 Method A is the method normally specified for regula-tory purposes when testing fire-retardant-treated wood that isintended for exterior applic
11、ations.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 required, but water shall not impinge directly onthose surfaces which are not exposed either t
12、o 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.1This practice is under the jurisdiction of ASTM Committee D07 on Wood andare the direct responsibility of Subcom
13、mittee D07.07 on Fire Performance of Wood.Current edition approved Feb. 1, 2017. Published March 2017. Originallyapproved in 1970. Last previous edition approved in 2010 as D2898 10. DOI:10.1520/D2898-10R17.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer
14、 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, CA 90601, http:/icc-es.org.4Available from Underwriters Laboratories, Inc.,
15、 333 Pfingsten Road,Northbrook, IL 60062, http:/.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the D
16、ecision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.15.3 Accompany drying cycles with heating that is thermo-statically controlled. The controlling temperature shall be thea
17、ir 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 across the surface of the decks at a rate ofat least 25 ft/mi
18、n (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 specimen surface. Use sunlamps5providing UV characteristics of 5.
19、0 W/m2irradiance 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 fraction thereof.5.5 Water Spray Calibrations:5.5.1 Measure the horizo
20、ntal 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 suitable for this purpose.5.5.2.1 For Method A, the water usage sha
21、ll 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 nozzle and uneven spray patterns. Make adjustments whennecessary.
22、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 quality, especially pH and hardness, as it canimpact the accelerated
23、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 intended sheathing.NOTE 2It is acceptable to mount specimens in
24、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 slope ranging from 4 in 12 minimum to 8in 12 maximum.7. Exposure C
25、ycle7.1 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 (3 days) of drying.7.1.3 Apply water in a moderately fine spray
26、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).7.1.3.1 Recirculation of the water is not permitted.7.1.3.2 For decks
27、intended for testing by Test MethodsE108, 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 one or more cycles, change the positionof the specimens within the apparatus so
28、 that each specimenoccupies every location within the apparatus for an approxi-mately equal number of cycles.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-two 24-h cycles. Each cycle is to consist of 4
29、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/minm2) of specimen surface. Thetemperature shal
30、l 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 (66 6 3C), withthis temperature attained within
31、 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 specimenoccupies every location within the apparatus for an approxi-mately equal
32、number of cycles.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.7.3.3 For the water exposure, use spray n
33、ozzles 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 MethodsE108, nozzles shall be mounted approximately two feet abovethe test decks.5Ge
34、neral Electric Type H275 RUV (275 W) or Osram Ultra-Vitalox (300 W), orequivalent, is suitable. General Electric no longer manufactures the Type H275 bulb.If you are aware of alternative suppliers, please provide this information to ASTMInternational Headquarters. Your comments will receive careful
35、consideration at ameeting of the responsible technical committee,1which you may attend.D2898 10 (2017)27.3.3.2 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
36、drained from the system and replaced with freshwater. For all other wetting cycles, fresh water shall beintroduced at a rate that provides a minimum of 5 gal (19 L) offresh water per nozzle, per cycle.7.3.4 Drying shall utilize sunlamps for both heat and UVexposure, with supplemental heaters as requ
37、ired to maintain atemperature of 145F to 155F (63C to 68C) with thistemperature attained within 15 min from the start of drying.7.3.5 At the end of one or more cycles, change the positionof the specimens within the apparatus so that each specimenoccupies every location within the apparatus for an ap
38、proxi-mately equal number of cycles.7.4 Method D:7.4.1 The total duration of this method is 97 days.7.4.2 Subject 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
39、) of drying. The water exposure of theseventh cycle is six days.7.4.3 Apply water in a moderating 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/min-ft2(0.30 L/min-m2) of specimen surface at a temp
40、era-ture between 35 and 60F (2 and 16C).7.4.3.1 Recirculation of the water is not permitted.7.4.3.2 For decks intended for testing by Test MethodsE108, 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 (
41、57 to 60C).7.4.5 At the end of one or more cycles, change the positionof the specimens within the apparatus so that each specimenoccupies every location within the apparatus for an approxi-mately equal number of cycles.8. Conditioning8.1 Upon completion of the prescribed exposure, the speci-men shal
42、l be conditioned in accordance with the applicable firetest standard.8.2 For decks intended for testing by Test Methods E108,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. Report9
43、.1 Report the following information:9.1.1 The accelerated weathering method (A, B, C, or D)used.9.1.2 Description of the specimens.9.1.2.1 Include information about the fire-retardant treat-ment including any surface coating and any identifying marks.9.1.2.2 Visual observations of the specimens befo
44、re andafter the accelerated weathering.9.1.3 Description of the weathering apparatus or chamber:9.1.3.1 The horizontal projected area over which eachnozzle discharges water to the nearest square foot (0.09 m2).9.1.3.2 The slope of the test specimen (see 6.2).9.1.3.3 Information on the UV lamps used,
45、 if used.9.1.3.4 Any deviations from the specifications in the stan-dard.9.1.4 Describe any means used to protect surfaces that arenot exposed to weather in the assembled form or fire in thesubsequent test (see 5.2).9.1.5 Results of the water spray calibration (see 5.5).9.1.6 The characteristics or
46、quality of the water, includingpH and hardness (see 5.5.5 and Note 1).9.1.7 The quantity of water that was re-circulated (see7.1.3.1, 7.2.3, 7.3.3.2,or7.4.3.1).9.1.8 Rate of flow of forced air movement across the surfaceof the specimens (see 5.3).10. Keywords10.1 fire retardant; fire retardant-treat
47、ed wood; fire testing;weatheringAPPENDIX(Nonmandatory Information)X1. COMMENTARYX1.1 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
48、 Method B aredescribed in various publications of that laboratory.X1.3 A research 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 Metho
49、d C is part of the acceptance criteria for classi-fied wood roof systems of the ICC Evaluation Service. Theoption of successful fire tests after the exposure of the“amended rain test” was developed as an alternative to their6“Correlation of ASTM Exposure Tests for Evaluating Durability of Fire-Retardant Treatment of Wood,” by C.A. Holmes, Forest Products Laboratory,Research Paper FPL 194, U.S.D.A. Forest Service, 1973.D2898 10 (2017)3requirement for successful fire tests of specimens exposed tothe rain test of Method A of this standard and addi
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