1、Designation: D 2898 07Standard 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 o
2、f 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 practice covers the durability of a fire-retardanttreatment of wood under exposure to accelerated weathering.T
3、wo conditioning methods are described, both suitable forapplication to a test specimen prior to subjecting that specimento an appropriate fire test.1.2 This practice is applicable to wood products that havebeen treated with fire-retardant chemicals by pressure impreg-nation.1.3 The test specimens ar
4、e to be in the form of, or suitablefor fabrication into, test specimens , such as those described inTest Test Methods E84, E 108, and E 1354 and other standardtest methods for evaluating the fire performance of fire-retardant-treated wood products.1.4 The text of these test methods references notes
5、andfootnotes that provide explanatory material. These notes andfootnotes (excluding those in tables and figures) shall not beconsidered as requirements of these test methods.1.5 The values stated in inch-pound units are to be regardedas standard. The values given in paranthese are for informationonl
6、y.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 health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced
7、 Documents2.1 ASTM Standards:2D9 Terminology Relating to Wood and Wood-Based Prod-uctsE84 Test Method for Surface Burning Characteristics ofBuilding MaterialsE 108 Test Methods for Fire Tests of Roof CoveringsE 176 Terminology of Fire StandardsE 1354 Test Method for Heat and Visible Smoke ReleaseRat
8、es for Materials and Products Using an Oxygen Con-sumption Calorimeter3. Terminology3.1 DefinitionsDefinition used in this practice are inaccordance with Terminology D9 and Terminology E 176,unless otherwise indicated.4. Significance and Use4.1 These test methods provide a choice between twomethods
9、of exposing fire-retardant-treated wood products orassemblies to controlled accelerated weathering or condition-ing.4.2 The conditioning simulates effects of leaching, drying,temperature and, in one method, ultraviolet light.4.3 Method A is the method normally specified for regula-tory purposes when
10、 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 required, but water sh
11、all 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.5.3 Heating shall be thermostatically con
12、trolled. Forced airmovement shall be uniform across the specimen surface, withprovisions made for adequate air changes to assure thoroughdrying.5.4 In Method B, ultraviolet light shall be distributed asevenly as possible over the specimen surface, using sunlamps31These test methods are under the jur
13、isdiction of ASTM Committee D07 onWood and are the direct responsibility of Subcommittee D07.07 on Fire Perfor-mance of Wood.Current edition approved April 15, 2007. Published May 2007. Originallyapproved in 1970. Last previous edition approved in 2004 as D 2898 94 (2004).2For referenced ASTM standa
14、rds, 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.3General Electric Type H275 RUV (275 W) or Osram Ultra-Vitalox (300 W), orequivalent, is
15、 suitable.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.directed normal to, and mounted 26 in. (660 mm) above thespecimen measured from the bottom of the lamp. One lampshall be used for each 8 ft2(0.74 m2) of specimen, or fractiont
16、hereof.6. Test Specimen6.1 The test specimen shall include all those essential partsof the corresponding fire test specimen that may be subjectedto weather exposure in normal use. Shingles or shakes shall beapplied to their intended sheathing.NOTE 1Specimens may be mounted in sections that can be re
17、as-sembled subsequently without trimming into the appropriate fire testspecimen.6.2 The specimen surface shall have a slope of 4 in 12 inMethod A. For Method B, the surface shall have a sloperanging from 4 in 12 minimum to 8 in 12 maximum.7. Exposure Cycle7.1 Method A:7.1.1 Subject the specimens to
18、an exposure cycle consistingof twelve one-week cycles. Each cycle is to consist of 96 h ofwater exposure and 72 h of drying.7.1.2 Apply water in a moderately fine spray uniformly overthe exposed specimen surfaces by spray nozzles that deliver anaverage of 0.7 in. (17.8 mm) of water per hour (0.0073g
19、al/minft2(0.30 L/minm2) of specimen surface) at a tempera-ture between 35 and 60F (2 and 16C). Do not recirculate thewater (see Note 2).7.1.3 Dry at a thermostatically controlled temperature of135 to 140F (57 to 60C). The controlling temperature shallbe the air temperature measured 1 in. (25.4 mm) a
20、bove thespecimen surface. Accompany drying with air movementdirected across the face of the specimens at a rate of at least 25ft/min (7.62 m/min).7.1.4 At the end of each cycle, change the position of eachspecimen within the apparatus so that each specimen orsegment occupies approximately an equal n
21、umber of cycles ineach location used.7.2 Method B:7.2.1 Subject the specimen to a 24-h exposure cycle con-sisting of 4 h wetting, 4 h drying, 4 h wetting, 4 h drying, and8 h rest. Repeat this cycle for a total of 1000 h.7.2.2 Apply water in a moderately fine spray uniformly overthe exposed specimen
22、surface at a rate of 0.3 6 0.02 gal/minft2(12.2 6 0.8 L/minm2) of specimen surface. The tem-perature shall not exceed 90F (32C). During the first threecycles, drain all water rather than recirculate it. In eachsubsequent wetting period, circulate a volume of at least 5 gal(18 L) of fresh water throu
23、gh each spray head.NOTE 2Water quality may be important in some cases, especially pHand hardness, and should be noted.7.2.3 Dry at a temperature of 150 6 5F (63 6 3C), withthis temperature attained within 15 min from the start ofdrying. The controlling temperature shall be the air tempera-ture 1 in.
24、 (25.4 mm) above the specimen surface. Obtain thetemperature by bare thermocouples or other temperature sen-sors that are protected from the direct radiation of the lamps bya shield not larger than 2 in.2(1290 mm2). Accompany dryingwith air movement directed across the face of the specimen ata rate
25、of at least 25 ft/min (7.62 m/min). Exposure to theultraviolet sunlamps shall be continuous throughout the dryingperiod.7.2.4 At the end of one or more cycles, change the positionof the specimens within the apparatus so that each specimen orsegment occupies approximately an equal number of cycles in
26、each location used.8. Conditioning8.1 Upon completion of the prescribed exposure, the speci-men shall be conditioned in accordance with the applicable firetest standard.9. Keywords9.1 fire retardant; fire retardant-treated wood; fire testing;weatheringAPPENDIX(Nonmandatory Information)X1. COMMENTARY
27、X1.1 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 researc
28、h 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.44“Correlation of ASTM Exposure Tests for Evaluating Durability of Fire-Retardant Treatment
29、 of Wood,” by C.A. Holmes, Forest Products Laboratory,Research Paper FPL 194, U.S.D.A. Forest Service, 1973.D2898072ASTM 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 a
30、dvised that determination of the validity 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, eith
31、er reapproved or withdrawn. Your comments are invited either for revision 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.
32、 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 (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).D2898073
