1、Designation: D4799/D4799M 08 (Reapproved 2013)1D4799/D4799M 17Standard Practice forAccelerated Weathering Test Conditions and Procedures forBituminous Materials (Fluorescent UV, Water Spray, andCondensation Method)1This standard is issued under the fixed designation D4799/D4799M; the number immediat
2、ely following the designation indicates theyear of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of lastreapproval. A superscript epsilon () indicates an editorial change since the last revision or reapproval.1 NOTEUnits informat
3、ion was editorially corrected in July 2013.1. Scope1.1 This practice describes test conditions and procedures for fluorescent UV and condensation exposures conducted accordingto Practices G151 and G154 for bituminous roofing and waterproofing materials that have a minimum softening point ofapproxima
4、tely 95C 200F as determined by Test Method materials. (See D36. (Also see Terminology G113.)1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in eachsystem may not be exact equivalents; therefore, each system shall be used indep
5、endently of the other. Combining values from thetwo systems may result in non-conformance with the standard.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety
6、and health practices and determine the applicability of regulatorylimitations prior to use.1.4 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards
7、, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D36D36/D36M Test Method for Softening Point of Bitumen (Ring-and-Ball Apparatus)D1669D1669/D1669M Practice for Preparation of Test Panels forAccel
8、erated and Outdoor Weathering of Bituminous CoatingsD1670D1670/D1670M Test Method for Failure End Point in Accelerated and Outdoor Weathering of Bituminous MaterialsG113 Terminology Relating to Natural and Artificial Weathering Tests of Nonmetallic MaterialsG141 Guide for Addressing Variability in E
9、xposure Testing of Nonmetallic MaterialsG147 Practice for Conditioning and Handling of Nonmetallic Materials for Natural and Artificial Weathering TestsG151 Practice for Exposing Nonmetallic Materials in Accelerated Test Devices that Use Laboratory Light SourcesG154 Practice for Operating Fluorescen
10、t Ultraviolet (UV) Lamp Apparatus for Exposure of Nonmetallic Materials3. Summary of Test Method3.1 Thin films of bitumen are uniformly applied to aluminum panels. Shingles and similar materials are cut to size and exposedto specified cycles of temperature, light, and water. A choice of threesix tes
11、t cycles is given along with options for determiningthe period of exposure and evaluating results.4. Significance and Use4.1 This weathering apparatus is used for comparing the weathering characteristics of bituminous materials against a controlmaterial for which the outdoor weathering characteristi
12、cs are known. It is not possible to establish a precise correlation between1 This practice is under the jurisdiction ofASTM Committee D08 on Roofing and Waterproofing and is the direct responsibility of Subcommittee D08.02 on Steep RoofingProducts and Assemblies.Current edition approved July 1, 2013
13、June 1, 2017. Published July 2013July 2017. Originally approved in 1988. Last previous edition approved in 20082013 asD4799 08.D4799/D4799M 08 (2013)1. DOI: 10.1520/D4799_D4799M-08R13E01.10.1520/D4799_D4799M-17.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Custo
14、mer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the
15、 previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright AS
16、TM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1accelerated and natural weathering because (1) there are geographical climatic variations, local weather variations, and variationsin local pollutants, and (2) the relation between accelerated and n
17、atural weathering is material dependent. Acceleration factorsdiffer between materials as well as between formulations of the same material. Guide G141 provides guidance regarding this issue.NOTE 1This practice can be used for other than bituminous materials, but the significance and use have not bee
18、n evaluated.5. Apparatus5.1 The fluorescent UVand condensation apparatus used shall conform to the requirements defined in Practices G151 and G154.5.2 LampsUnless otherwise specified, the The lamps shall be fluorescent UVA-340 lamps as described in 6.1.3.1 of PracticeG154.5.2.1 Other fluorescent UV
19、lamps meeting the size and electrical characteristics in 5.2 may be used if mutually agreed upon andprovided that the lamp and spectral energy distribution are reported in conformance with Section 9.5.3 MoistureIt is permitted to expose the test specimens to moisture in the form of water spray, cond
20、ensation, or highhumidity.5.3.1 Water SprayIt is permitted to equip the test chamber with a means to introduce intermittent water spray onto the testspecimens under specified conditions. The spray shall be uniformly distributed over the samples. The spray system shall be madefrom corrosion resistant
21、 materials that do not contaminate the water used.5.3.1.1 Spray Water QualitySpray water shall have a conductivity below 5 S/cm, contain less than 1-ppm solids, and leaveno observable stains or deposits on the specimens. Very low levels of silica in spray water can cause significant deposits on thes
22、urface of test specimens. Care should be taken to keep silica levels below 0.1 ppm. In addition to distillation, a combination ofdeionization and reverse osmosis can effectively produce water of the required quality. The pH of the water used shall be reported.See Practice G151 for detailed water qua
23、lity instructions.6. Test Specimens6.1 Unless otherwise agreed upon, test specimens shall be approximately 3 by 6 in. 75 by 150 mm. Bituminous materials withadequate flow resistance shall be applied as uniform coatings on aluminum panels in accordance with Practice D1669D1669/D1669M. Fabricated mate
24、rials such as bituminous roofing, shingles, and similar products shall be cut to size and their weathersurfaces exposed. If these are too flexible to sustain their own weight in a vertical position, they may be mounted on aluminumpanels.6.1.1 Replicate specimens are desirable to provide Unless other
25、wise specified, expose at least three replicate specimens of eachtest and control material using nondestructive tests of change in material properties and six replicate specimens using destructivetests. Do not mask the face of each specimen for the purpose of showing on one panel a record of degrada
26、tion at different timeintervals. Retention of an unexposed specimen is recommended as it is difficult to mask a specimen to prevent exposure tocondensation.Misleading results may be obtained by this method because the masked portion of the specimen is still exposed totemperature and moisture that in
27、 many cases will affect results. Instead, provide a replicate set of specimens for each time interval.6.1.2 Follow the procedures described in PracticeRetention of an unexposed specimen is G147 for identification, conditioning,and handling of specimens of test and control materials prior to, during,
28、 and after exposure.recommended for comparison withexposed specimens when destructive tests are used to measure change in material properties.7. Procedure7.1 Proceed in accordance with Section 9 of Practice G154.7.2 Apparatus shall be operated continuously, except for intervals for repositioning of
29、samples or inspection of samples,according to one of the following cycles. The temperature specifications are for an uninsulated black panel thermometer. Forequipment that requires an irradiance setting for its operation, it shall be 0.89 6 0.02 W/(m2nm) at 340 nm. Specimens shall beconfined to an e
30、xposure area in which the irradiance is at least 90 % of the irradiance at the center of the exposure area. Unlessit is known that irradiance uniformity meets this requirement, use one of the procedures described in Practice G154, Section 9.5,to ensure equal radiant exposure on all specimens or to c
31、ompensate for differences within the exposure chamber. If the specimensdo not completely fill all of the spaces, fill the empty spaces with blank panels of corrosion resistant material to maintain the testconditions within the chamber.Cycle A 4 h UV at 60 2.5C, alternating with 4 h condensationat 50
32、 2.5C.Cycle B 20 h UV at 60 2.5C, alternating with 4 h condensationat 50 2.5C.Cycle C 20 h UV at 80 2.5C, alternating with 4 h condensationat 50 2.5C.Cycle D 4 h UV at 60 2.5C, 15 min water spray, alternating with3.75 h condensation at 50 2.5C.Cycle E 20 h UV at 60 2.5C, 15 min water spray, alternat
33、ing with3.75 h condensation at 50 2.5C.Cycle F 20 h UV at 80 2.5C, 15 min water spray, alternating with3.75 h condensation at 50 2.5C.D4799/D4799M 1727.3 If inspection of the panels is to be performed at any stage in the cycle, the interruption of the test procedure shall take onlysufficient time to
34、 allow for such inspection. The time taken for inspection of the samples shall not be counted as part of theexposure.NOTE 2The cycle to be employed shall be specified in the product standard.NOTE 3The operational fluctuations, that is, the positive and negative deviations from the specified set poin
35、ts for the irradiance and temperature, areallowable deviations from the set points during equilibrium operation of the equipment. They do not imply that the user is allowed to program a set pointhigher or lower than that specified. Operate the apparatus to maintain the allowable operational fluctuat
36、ions. If the latter are greater than the maximumallowable after the equipment has stabilized, discontinue the test and correct the cause of the problem before continuing.8. Period of Exposure and Evaluation of Results8.1 The duration of the exposure under this practice shall be one of the following:
37、8.1.1 A mutually agreed upon number of hours of exposure,8.1.2 The number of hours of exposure required to produce a mutually agreed upon minimum amount of change in the testspecimen, or8.1.3 The number of hours required to produce mutually agreed upon minimum acceptable change in either the test sp
38、ecimenor a mutually agreed upon standard sample.8.2 It is permitted to evaluate changes in the exposed samples visually each day by comparing them with unexposed samples,or in terms of the number of hours exposure required to produce physical or chemical changes as determined by Test MethodD1670D167
39、0/D1670M.9. Report9.1 In addition to the items specified in Practice G151, the report shall include the following:9.1.1 Test cycle employed (in accordance with 7.2),9.1.2 Manufacturer and designation of the fluorescent lamp employed, and9.1.3 Coating thickness employed.9.1.4 Method of sample reposit
40、ioning, if used, or other means of assuring equal radiant exposure on all specimens orcompensation for differences in irradiance within the exposure chamber.9.1.5 Type of fluorescent/condensation device used, that is, irradiance controlled or non-controlled.10. Precision and Bias10.1 PrecisionThe re
41、peatability of results obtained in exposures conducted according to this practice will vary with thematerials being tested, the material property being measured, and the specific test conditions and cycles that are used. It is essentialto determine reproducibility of the exposure/property measuremen
42、t process when using the results from exposures conductedaccording to this practice in product specifications.10.2 BiasBias cannot be determined because no acceptable standard weathering reference materials are available.11. Keywords11.1 accelerated weathering; bituminous materials; degradation; exp
43、osure; fluorescent UV and condensation; light exposure;roofing; ultraviolet; waterproofingASTM 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
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