1、Designation: E2749 15a An American National StandardStandard Practice forMeasuring the Uniformity of Furnace Exposure on TestSpecimens1This standard is issued under the fixed designation E2749; the number immediately following the designation indicates the year oforiginal adoption or, in the case of
2、 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 standard provides general principles for measuringthe uniformity of the furnace exposure o
3、n specimens tested inaccordance with Test Methods E119, E814, E1529, E1725,E1966 and E2336.1.2 This practice specifies the materials and the constructionrequirements for a standardized test specimen used to providea mounting surface for the instrumentation that measuresfurnace exposure.1.3 The instr
4、umentation records temperatures, pressure dif-ferentials and oxygen content near the surface of the testspecimen.1.4 The values stated in SI units are to be regarded as thestandard. The units given in parentheses are for informationonly.1.5 This standard is used to measure and describe theresponse o
5、f materials, products, or assemblies to heat andflame under controlled conditions, but does not by itselfincorporate all factors required for fire hazard or fire riskassessment of the materials, products, or assemblies underactual fire conditions.1.6 Fire testing is inherently hazardous. Adequate sa
6、fe-guards for personnel and property shall be employed inconducting these tests.1.7 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 det
7、ermine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C1396/C1396M Specification for Gypsum BoardE119 Test Methods for Fire Tests of Building Constructionand MaterialsE176 Terminology of Fire StandardsE814 Test Method for Fire Tests of Penetratio
8、n FirestopSystemsE1529 Test Methods for Determining Effects of Large Hy-drocarbon Pool Fires on Structural Members and Assem-bliesE1725 Test Methods for Fire Tests of Fire-Resistive BarrierSystems for Electrical System ComponentsE1966 Test Method for Fire-Resistive Joint SystemsE2336 Test Methods fo
9、r Fire Resistive Grease Duct Enclo-sure Systems2.2 ISO Technical Report:ISO/TR 834-2 Fire resistance tests Elements of buildingconstruction Part 2: Guide on measuring uniformity offurnace exposure on test samples3. Terminology3.1 DefinitionsFor definitions of terms used in thispractice, refer to Ter
10、minology E176.3.2 Definitions of Terms Specific to This Standard:3.2.1 effective area of the furnace openingfurnace open-ing within the boundaries of the monitoring instrumentation.4. Summary of Practice4.1 This practice consists of preparing a standardized testspecimen to represent test specimens d
11、escribed in Test Meth-ods E119, E814, E1529, E1725, E1966 and E2336. The1This practice is under the jurisdiction of ASTM Committee E05 on FireStandards and is the direct responsibility of Subcommittee E05.11 on FireResistance.Current edition approved June 1, 2015. Published July 2015. Originally app
12、rovedin 2010. Last previous edition approved in 2015 as E2749-15. DOI:10.1520/E2749-15A.2For referenced ASTM 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 Summa
13、ry page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1standardized test specimen provides a low cost, easily con-structed supporting construction for the mounting of instru-mentation that measures the exposure imp
14、osed by the furnaceonto test specimens.4.2 The standardized test specimen consists of two layers of15.9 mm (58 in.) thick Type X gypsum board on the surfacefacing the furnace chamber attached to steel channels and asingle layer of structural panels (plywood or oriented strandboard) attached to the s
15、teel channels on the surface away fromthe furnace chamber. The gypsum board provides a fire-resistive surface for the mounting of the instrumentation. Thestructural panels provide stability for the steel support chan-nels.4.3 Instrumentation to measure the thermal impact due toexposure to the furnac
16、e upon the standardized test specimen isinstalled at various locations on the exposed surface of thestandardized test specimen. Probes used to gather air sampleswithin the furnace chamber are also installed.4.4 The standardized test specimen is exposed to the time-temperature curve specified in refe
17、renced ASTM fire teststandards for a time period of 45 min during which time dataare recorded by the instrumentation mounted on the standard-ized test specimen.4.5 The data provide a record of the conditions and unifor-mity of the furnace exposure upon standardized test specimens.The area bounded by
18、 the instrumentation installed on thestandardized test specimen is designated as the effective area ofthe furnace opening.5. Significance and Use5.1 This practice describes a procedure to gather dataintended to measure the uniformity of exposure conditionsupon test specimens for the fire test method
19、s described in TestMethods E119, E814, E1529, E1725, E1966 and E2336. Thecollected data from furnaces are intended to form a basis forperformance requirements for the furnaces described in thereferenced standards.5.2 This practice does not include requirements for furnaceperformance.5.3 In this proc
20、edure, the standardized test specimen issubjected to one or more specific sets of laboratory testconditions. If different test conditions are substituted or theend-use conditions are changed, it is not always possible by orfrom this procedure to predict changes in the fire-test-responsecharacteristi
21、cs measured. Therefore, the results are valid onlyfor the fire-test-exposure conditions described in this proce-dure.5.4 The attention of all persons connected with the conductof this practice is drawn to the fact that fire testing is hazardousand that there is a possibility that harmful smoke and g
22、ases aredeveloped during the test. There is also a possibility thatmechanical and operational hazards develop during the con-struction of the test specimen and the disposal of the testresidues. An assessment of all potential hazards and risks tohealth shall be made and safety precautions shall be id
23、entifiedand provided. Written safety instructions shall be issued.Appropriate training shall be provided to relevant personnel.Laboratory personnel shall ensure that they follow writtensafety instructions at all times.6. Apparatus6.1 The furnace(s) and restraining frame(s) used to conducttests in ac
24、cordance with Test Methods E119, E814, E1529,E1725, E1966 and E2336 shall be used.6.2 Standardized Test Specimen:6.2.1 MaterialsThe materials used to construct the stan-dardized test specimen shall consist of the following: gypsumboard, structural panels, cold-formed steel supports and fasten-ers.6.
25、2.1.1 The gypsum board shall be minimum 15.9 mm (58in.) thick complying with the requirements of Type X asdefined in Specification C1396/C1396M.6.2.1.2 The structural panels shall be minimum 18 mm(nominal34 in.) thick. Typical materials include plywood andoriented strand boards.6.2.1.3 The cold-form
26、ed steel joists for horizontal speci-mens shall be fabricated from minimum 1.4 mm thick (0.055in.) steel. The cold formed steel joists shall be “C” shapedhaving a minimum depth of 240 mm (912 in.), a minimumflange width of 40 mm (158 in.) and a minimum lip length of12 mm (12 in.).6.2.1.4 The cold-fo
27、rmed steel wall studs for vertical speci-mens shall be fabricated from minimum 0.9 mm thick (0.035in.) steel. The cold-formed steel wall studs shall be “C” shapedhaving a minimum depth of 90 mm (312 in.), a minimum flangewidth of 30 mm (114 in.) and a minimum folded back returnflange legs of 5 mm (1
28、4 in.).Dimensions in millimetres.FIG. 1 Horizontal Standardized Test Specimen, Location ofJoists and Track ChannelsE2749 15a26.2.1.5 The cold-formed steel track channels for the hori-zontal and vertical specimens shall be “C” shaped having adepth compatible with the joists or wall studs being used.6
29、.2.1.6 Steel fasteners used to attach the gypsum board tothe studs shall be designed for the attachment of gypsum boardto steel supports. Typical screws have a thread diameter of 5mm (14 in.) and a head diameter of 8 mm (38 in.). The steelfasteners used to attach the inner layer shall have a minimum
30、length of 25 mm (1 in.). The steel fasteners used to attach theexposed layer shall have a minimum length of 40 mm (158 in.).6.2.1.7 Fasteners used to attach the structural panels to thestuds shall be designed for the attachment of the panels to steelsupports.6.2.2 Construction MethodStandardized hor
31、izontal testspecimen.6.2.2.1 The construction details with respect to the locationof the joists, track channels, gypsum board and the structuralpanels are shown in Figs. 1-3. The construction details assumea furnace opening of 4.2 by 4.2 m (13 ft 938 in. by 13 ft 938in.). Modifications to dimensions
32、 are necessary for otherfurnace openings.6.2.2.2 The steel joists shall be spaced 300 to 450 mm (1178in. to 1734 in.) on center. The joists are inserted into the trackchannels. The use of steel clip angles are permissible tofacilitate the attachment of the joists to the track channels.6.2.2.3 The in
33、ner layer of gypsum board shall be attached tothe joists with the steel screws spaced a maximum of 200 mm(778 in.) on center along each joist. A distance of 10 to 15 mm(38 to58 in.) shall be provided between the screws and theedges of the gypsum board.NOTE 1The inner layer, or base layer, of gypsum
34、board is in contactwith the joists.6.2.2.4 The exposed layer of gypsum board shall be at-tached to the joists with steel screws spaced a maximum 200mm (778 in.) on center along each joist and shall be spaced 100mm (4 in.) from the screws used to attach the inner layer. Adistance of 10 to 15 mm (38 t
35、o58 in.) shall be providedbetween the screws and the edges of the gypsum board.NOTE 2The exposed layer, or outside layer, of gypsum board is incontact with the inner layer of gypsum board.6.2.2.5 The structural panels shall be attached to the joistswith steel screws spaced a maximum of 150 mm (578 i
36、n.) oncenter along each joist. A distance of 10 to 15 mm (38 to58 in.)shall be provided between the screws and the edges of thestructural panels. Holes are permissible in the structural panelsto facilitate the installation of the instrumentation.6.2.3 Construction MethodVertical Standardized TestSpe
37、cimen:6.2.3.1 The construction details with respect to the locationof the wall studs, track channels, gypsum board and thestructural panels are shown in Figs. 4-6. The constructiondetails assume a furnace opening of 3.1 by 3.1 m (10 ft. 2 in.by 10 ft. 2 in.). Modifications to dimensions are necessar
38、y forother furnace openings.6.2.3.2 The wall studs shall be spaced 300 to 450 mm (1178to 1734 in.) on center. The studs are inserted into trackchannels. The use of steel clip angles are permissible tofacilitate the attachment of the studs to the track channels.6.2.3.3 The inner layer of gypsum board
39、 shall be attached tothe studs with the steel screws spaced a maximum of 200 mm(778 in.) on center along each stud. A distance of 10 to 15 mm(38 to58 in.) shall be provided between the screws and theedges of the gypsum board.NOTE 3The inner layer, or base layer, of gypsum board is in contactwith the
40、 studs.6.2.3.4 The exposed layer of gypsum board shall be at-tached to the studs with steel screws spaced a maximum 200Dimensions in millimetres.FIG. 2 Horizontal Standardized Test Specimen, Location of Inner Layer of Gypsum Board and Structural PanelsE2749 15a3mm (778 in.) on center along each stud
41、 and shall be spaced 100mm (4 in.) from the screws used to attach the inner layer. Adistance of 10 to 15 mm (38 to58 in.) shall be providedbetween the screws and the edges of the gypsum board.NOTE 4The exposed layer, or outside layer, of gypsum board is incontact with the inner layer of gypsum board
42、.6.2.3.5 The structural panels shall be attached to the supportchannels with steel screws spaced a maximum of 150 mm (578in.) on center along each support channel. A distance of 10 to15 mm (38 to58 in.) shall be provided between the screws andthe edges of the structural panels. Holes are permissible
43、 in thestructural panels to facilitate the installation of the instrumen-tation.6.3 Furnace LimitationsFurnaces with dedicatedapplications, such as testing of ceiling assemblies, typicallyhave specific horizontal or vertical assemblies for this purposeand therefore do not include open restraining fr
44、ames.6.3.1 It is permissible to modify the standardized testspecimen to account for these limitations.6.4 InstrumentationThe instrumentation installed on thestandardized test specimen shall include plate thermometers, adirectional flame thermometer, bi-directional probes, Type Kthermocouples and air
45、 sampling probes.6.4.1 The plate thermometers (1)3shall be constructed asshown in Fig. 7.6.4.1.1 The plate part of the plate thermometer shall beconstructed from 150 61 mm long by 100 6 1 mm wide by 0.76 0.1 mm thick nickel alloy plate strips folded to the designshown in Fig. 7.6.4.1.2 A Type K ungr
46、ounded Inconel4sheathed thermo-couple having a maximum diameter of 1 mm shall be fixed tothe geometric center of the plate in the position shown in Fig.7 by a steel strip made from the same material as the plate. Thesteel strip shall be welded or screwed to the plate. The stripshall be 18 6 1mmby66
47、1 mm when it is spot welded to theplate (Fig. 7) and 25 6 1mmby66 1 mm when it is to bescrewed to the plate. The screw shall be a maximum 2 mm indiameter.3The boldface numbers in parentheses refer to a list of references at the end ofthis standard.4Inconel is a registered trademark of Special Metals
48、 Corporation.Dimensions in millimetres.FIG. 3 Horizontal Standardized Test Specimen, Location of Outer Layer of Gypsum BoardDimensions in millimetres.FIG. 4 Vertical Standardized Test Specimen, Location of WallStuds and Track ChannelsE2749 15a46.4.1.3 The assembly of the plate and thermocouple shall
49、 befitted with a pad of inorganic insulation material 97 6 1mmby97 6 1mmby106 1 mm thick. The density of the insulationmaterial shall be 280 6 30 kg/m3.6.4.1.4 The plate thermometers shall be aged by immersingin a pre-heated oven at 1000C for 1 h before their first use orexposed in a furnace following the time-temperature curvespecified in Test Methods E119 for a minimum of 90 min.6.4.2 The directional flame thermometers(2) shall be con-structed as shown in Fig. 8.6.4.2.1 The plate parts of the directional flame thermom-eters sha
