1、Designation: C1795 15C1795 17Standard Test Methods forHigh-Temperature Characterization of Gypsum Boards andPanels1This standard is issued under the fixed designation C1795; 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.1. Scope1.1 These test methods describe three bench top test methods for measuring the thermophysical responses of gypsum board
3、sand panels when exposed to high temperatures. The test methods are:1.1.1 High-temperature Core CohesionThis test method evaluates the ability of the test specimen to withstand a specifiedmechanical strain while exposed to elevated temperature.1.1.2 High-temperature ShrinkageThis test method evaluat
4、es dimensional changes in the test specimen when exposed toelevated temperatures.1.1.3 High-temperature Thermal InsulationThis test method evaluates the rate of heat transfer through the thickness of thetest specimen by measuring the length of time required to heat the center of the test specimen ov
5、er a specified temperature risewhen exposed to prescribed furnace conditions.1.2 The test methods appear in the following order:Test Method SectionHigh-temperature Core Cohesion 4High-temperature Shrinkage 5High-temperature Thermal Insulation 61.3 UnitsThe values stated in either inch-pound units or
6、 SI units (given in parenthesis) are to be regarded separately asstandard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently ofthe other. Combining values from the two systems may result in non-conformance with the standard.1.4 While th
7、ese tests are useful for evaluating fire properties of gypsum boards and panels, they are not suitable for predictingthe Test Methods E119 fire resistance performance of a specific gypsum protected assembly that has not previously been testedin accordance with Test Methods E119 and correlated to the
8、se tests.21.5 This standard is used to measure and describe the response of materials, products, or assemblies to heat and flame undercontrolled conditions, but does not by itself incorporate all factors required for fire hazard or fire risk assessment of the materials,products, or assemblies under
9、actual fire conditions.1.6 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 and health practices and determine the applicability of regulatorylimitations prior t
10、o use.1.7 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers
11、 to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:C11 Terminology Relating to Gypsum and Related Building Materials and SystemsE119 Test Methods for Fire Tests of Building Construction and MaterialsE631 Terminology of Building Constructions1 This test method is under the jurisdicti
12、on of ASTM Committee C11 on Gypsum and Related Building Materials and Systems and is the direct responsibility ofSubcommittee C11.01 on Specifications and Test Methods for Gypsum Products.Current edition approved Dec. 1, 2015June 1, 2017. Published January 2016June 2017. Originally approved in 2005.
13、 Last previous edition approved in 2015 as C1795 15.DOI: 10.1520/C1795-1510.1520/C1795-17.2 Shipp, P. H., and Yu, Q., “Thermophysical Characterization of Type X Special Fire Resistant Gypsum Board,” Proceedings of the Fire and Materials 2011 Conference,San Francisco, Jan. 1, 2011 Feb. 2, 2011, Inter
14、science Communications Ltd., London, UK, pp 417-426.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 previous version. Becauseit may not be technically possible to adequately depict all changes accu
15、rately, 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 ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United Sta
16、tes12.2 Other Standards:EN 520 Gypsum PlasterboardsDefinitions, Requirements and Test Methods3. Terminology3.1 GeneralRefer to Terminologies C11 and E631 for standard terminology on gypsum and related building materials,systems and building construction.3.2 Definitions of Terms Specific to This Stan
17、dard:3.2.1 Thermal Insulation Index (TI), na single value index that denotes the rate of heating at the center of the ThermalInsulation Test specimen as determined by the elapsed time to the nearest minute for the temperature to rise from 104 to 392F(40 to 200C).4. High-temperature Core Cohesion4.1
18、Summary of Test MethodThe high-temperature core cohesion of gypsum panel products is evaluated by applying a shearforce and bending moment to a cantilevered test specimen by hanging a weight from the free end of the specimen. The specimenis exposed to heating from two burner flames at a specified di
19、stance and location from its fixed end. The exposure of the specimento the burner flame results in the calcination of the specimen, which weakens the core matrix and results in deflection of the loaded,cantilevered specimen. When a specified deflection occurs, the specimen is examined for breakage.
20、This test is derived from anearlier version of the high-temperature core cohesion test found in EN 520.4.2 Significance and UseThis test method provides a procedure for evaluating the high temperature strain capacity of gypsumpanel products.4.3 Apparatus:4.3.1 Specimen Mounting DeviceAfixture capabl
21、e of rigidly supporting the specimen and weight in the horizontal plane. Thespecimen is clamped or otherwise held rigidly at one end in a cantilevered horizontal position. The mounting fixture shall providesufficient clearance of the end weight fixture above the horizontal base to allow for the full
22、 prescribed deflection of the specimen.(Figs. 1 and 2).4.3.2 Hanger StrapAbracket for suspending a weight from the free end of the test specimen consisting of an L-shaped metalstrap constructed of 20 gauge sheet metal or other suitable material. The short leg of the strap is 0.65 6 0.05 in. (16 6 1
23、mm) inlength. The long leg of the strap has a mounting hole drilled in it near the outer extremity and is of sufficient length that the hookor wire by which the loading weight is suspended from the strap does not contact the specimen.4.3.3 Loading WeightA weight fitted with a hook or wire for hangin
24、g it from the free end of the specimen by means of thehanger strap. The loading weight may be configured as a cup or disk to receive weighted shot or slotted disks to adjust the weightfor different test specimen thicknesses. The total weight of the entire loading device (hanger strap, loading weight
25、, suspension wireor hook) shall correspond to the nominal thickness of the sample in accordance with Eq 1, rounded to the nearest integer multipleof 25, and shown in Table 1:FIG. 1 Side View of Core Cohesion Test ApparatusC1795 1724.3.4 PlatformAn adjustable height platform to limit the deflection o
26、f the specimen to the specified distance of 0.4 6 0.05in. (10 6 1 mm) (See Fig. 1.)4.3.5 Heating System:4.3.5.1 Two propane Meker burners having a nozzle diameter of 1.14 6 0.04 in. (29 6 1.0 mm) and a gas orifice of 0.03 60.01 in. (0.76 6 0.25 mm) are mounted horizontally with their nozzles facing
27、each other (Figs. 2 and 3).4.3.5.2 The axes of the burners are aligned to within 0.05 in. (1 mm).4.3.5.3 Needle valves at the base of each burner provide for fine adjustment of the gas flow rate to control flame shape andtemperature.4.3.5.4 Natural gas or propane is supplied to each burner from a si
28、ngle source via a tube with a Y fitting. A pressure regulatorto control the pressure and a pressure gauge to measure the pressure are installed in the line between the source and the Y fitting.The gas pressure supplied to the Y fitting shall be 0.5 6 0.1 psig (3.5 6 0.7 kPa). A flow meter may option
29、ally be installed to aidin monitoring and maintaining consistent gas flow rates (Fig. 4).4.3.5.5 The burners are adjusted to produce stable, premixed flames with the characteristic blue zone of the flame covering theentire screen area at the mouth of the burner and projecting 3/838 6 181/8 in. in. (
30、10 6 3 mm) from the burner. Beyond the bluepremixed zone, both flames project horizontally in a turbulent deflagration contacting the specimen near its bottom edge with littleor no vertical deflection due to buoyancy or forced convection in the space between the burner and where the flame strikes th
31、e testspecimen perpendicularly. The zone of heating extends from the bottom edge of the specimen upwards to the top edge.4.3.6 ThermocouplesInsulated chromel-alumel thermocouples (Type K) 1161/16 in. in. (1.6 mm) diameter stainless steelsheathed, ungrounded tip 36 ga.4.3.6.1 The thermocouples are al
32、igned horizontally with the top of the burners and secured to the burner with a hose clamp (Fig.3).FIG. 2 Top View of Core Cohesion Test ApparatusW510.6 S t0.50D (1)Where:W = Total weight of loading device, oz., andt = Nominal board thickness, in.TABLE 1 Required Loading Device Weight for Each Board
33、ThicknessNominal Board Thickness Weight of Loading Device12 in. (12.7 mm) 10.6 0.4 oz (300 10 g)58 in. (15.9 mm) 13.2 0.4 oz (375 10 g)34 in. (19.1 mm) 15.9 0.4 oz (450 10 g)C1795 1734.3.7 Gauge Blocks, 0.2 in. (5 mm), 0.4 in. (10 mm), and 1.0 in. (25.4 mm).4.3.8 StopwatchTiming device capable of me
34、asuring elapsed time in one second intervals or less.4.4 SamplingTest specimens shall be taken from the sample lot of gypsum panel products as indicated in 4.5.4.5 Test Specimens:4.5.1 Cut six specimens from the gypsum board sample using a saw to insure straight, square edges.4.5.2 Each specimen sha
35、ll be 12.0 6 0.1 in. (300 6 2 mm) long by 1.75 6 0.05 in. (45 6 1 mm) wide, with the edges of thespecimen not less than 4 in. (100 mm) from any edge of the full gypsum board sample. Specimens can be tested when cut fromany orientation from the sample board for specific evaluation but since the orien
36、tation can contribute to the measured results, theorientation must be identified and recorded for each test result. Common orientations for evaluation are the long edge of thespecimen parallel to the paper-bound or long edge of the board as manufactured or the long edge of the specimen parallel to t
37、heend perpendicular to the paper-bound or long edge of the board as manufactured.4.6 ConditioningCondition specimens to constant weight at a temperature of 85615F (29.568.5C) and relative humidity50 6 2 %.4.7 Procedure:4.7.1 Clamp one end of the test specimen in the supporting device in a cantilever
38、 configuration. The long edge extendslengthwise 10.25 6 0.05 in. (260 6 1 mm) from the support point to the free end of the test specimen. The short edge of the testspecimen is vertical (Figs. 1-3).4.7.2 Align the lower edge of the test specimen to the lowest point of the burner nozzles (Figs. 1 and
39、 3).4.7.3 Position the mid-point of the burner nozzles 4.0 6 0.05 in. 0.05 in. (100 6 1 mm) from the point of support (Figs. 1 and2).FIG. 3 Alignment of Burners and Thermocouples with Respect to Test SpecimenFIG. 4 Schematic of Gas Supply to BurnersC1795 1744.7.4 Position the mouth of each burner no
40、zzle 1.0 6 0.05 in. (25.4 6 1 mm) from the adjacent specimen face by means ofa gauge block (Figs. 2 and 3).4.7.5 Position each thermocouple parallel to the upper edge of the burner and 0.2 6 0.05 in. (5 6 1 mm) from the specimenface by means of a gauge block (Figs. 2 and 3).4.7.6 Place the hanger st
41、rap on the free end of the cantilevered test specimen, 10.25 6 0.05 in. (260 6 1 mm) from the supportpoint of the mounting device, and suspend the loading weight from it. The total weight of the suspended load shall be as specifiedin 4.3.3.4.7.7 Adjust the height of the platform so that the distance
42、 from the platform to the bottom of the suspended load is 0.4 6 0.05in. (10 6 1 mm) above the surface of the platform. Verify the spacing by means of a gauge block (Fig. 2).4.7.8 Open the gas valve, start the stopwatch and ignite both burners.4.7.8.1 Adjust the gas flow so that the temperature at ea
43、ch thermocouple is 1832 6 90F (1000 6 50C).4.7.8.2 Both flames shall be stabilized at the specified temperature with the characteristic appearance described in 4.3.5.5 within60 s of lighting the burners.4.7.9 The test is over when the specimen deflects downward and the load comes into contact with t
44、he surface of the platform.4.7.9.1 At the conclusion of the test, stop the stopwatch and shut off the burners.4.7.9.2 Visually inspect the specimen immediately after shutting off the burners.4.7.9.3 Observe if the specimen has broken into two or more distinct pieces at or before the time at which th
45、e load contactedthe platform.4.7.9.4 Record the elapsed time from the start to the end of the test and whether or not the specimen was broken into two ormore distinct pieces.4.7.10 Repeat steps 4.7.1 4.7.9.4 of the procedure for each of the six test specimens from the gypsum panel product sample.4.8
46、 ReportReport the number of specimens that remained intact, the number of specimens that broke into two or more distinctpieces, and the time to reach 0.4 in. (10 mm) deflection for each specimen.4.9 Precision and BiasNo information is presented about either the precision or bias of this test method
47、for measuringhigh-temperature core cohesion since the test result is qualitative.5. High-temperature Shrinkage Test5.1 Summary of Test MethodThis test method evaluates high-temperature shrinkage of gypsum panel products by exposingspecimen disks to prescribed temperature conditions in a muffle furna
48、ce and measuring the change in diameter before and afterheating exposure.5.2 Significance and UseThis test method evaluates the high-temperature shrinkage of gypsum panel products and is usefulfor estimating their behavior when exposed to fire.5.3 Apparatus:5.3.1 Drill Presscapable of running 620 rp
49、m.5.3.2 Hole Sawnominal 4 in. (100 mm) outside diameter with pilot drill bit removed.FIG. 5 Specimen PedestalC1795 1755.3.3 FurnaceBox furnace with PID control, 2012F (1100C) maximum temperature, 3500 W power, 240 VAC, volumetriccapacity 0.65 cu. ft. (18.4 l) with interior dimensions 14 9 9 in. (356 x 229 x 229 mm) and no exterior penetrations orvents.3,45.3.3.1 The furnace shall be capable of temperature control of 6 10F (6 5C) 610F (65C) up to and including 930F(500C) and 6 18F (6 10C) 618F (610C) for temp
