1、Standard Method of Test for Flash Point of Asphalt Binder by Cleveland Open Cup AASHTO Designation: T 48-171Technical Section: 2b, Liquid Asphalt Release: Group 3 (August 2017) American Association of State Highway and Transportation Officials 444 North Capitol Street N.W., Suite 249 Washington, D.C
2、. 20001 TS-2b T 48-1 AASHTO Standard Method of Test for Flash Point of Asphalt Binder by Cleveland Open Cup AASHTO Designation: T 48-171Technical Section: 2b, Liquid Asphalt Release: Group 3 (August 2017) 1. SCOPE 1.1. This method covers the procedure for the determination of flash point of asphalt
3、binder by the Cleveland open-cup apparatus. 1.2. This test method is applicable to asphalt binder with flash point between 80C (175F) and 400C (750F). Note 1Specifications commonly designate the Tag Open-Cup method (T 79) for asphalt binders and cutback asphalts having flash points below 93C (200F).
4、 1.3. The values stated in SI units are to be regarded as the standard. 1.4. This test may involve hazardous materials, operations, and equipment. This test does not purport to address all of the safety concerns associated with its use. It is the responsibility of the user to establish appropriate s
5、afety and health practices and determine the applicability of regulatory limitations prior to use. 2. REFERENCED DOCUMENTS 2.1. AASHTO Standards: R 18, Establishing and Implementing a Quality Management System for Construction Materials Testing Laboratories R 66, Sampling Asphalt Materials T 79, Fla
6、sh Point with Tag Open-Cup Apparatus for Use with Material Having a Flash Point Less Than 93C (200F) 2.2. ASTM Standards: C670, Standard Practice for Preparing Precision and Bias Statements for Test Methods for Construction Materials E1, Standard Specification for ASTM Liquid-in-Glass Thermometers E
7、220, Standard Test Method for Calibration of Thermocouples By Comparison Techniques E644, Standard Test Methods for Testing Industrial Resistance Thermometers 2017 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable
8、 law.TS-2b T 48-2 AASHTO 2.3. NCHRP Report: D.W. Christensen, and R. F. Bonaquist. National Cooperative Highway Research Program Report 530: Evaluation of Indirect Tensile Test (IDT) Procedures for Low-Temperature Performance of Hot Mix Asphalt. NCHRP, Transportation Research Board, Washington, DC,
9、2004. 3. SUMMARY OF TEST METHOD 3.1. The sample is placed in the tester and heated rapidly to begin with then at a slow rate. A small test flame is passed at a uniform rate in a level plane across the cup at specified intervals. The flash point is the lowest temperature at which application of the t
10、est flame causes the vapor at the surface of the liquid to flash. 4. APPARATUS 4.1. Cleveland Open-Cup TesterConsisting of the following parts; the parts must conform to t he dimensions shown and have the additional characteristics as noted. (See Figure 1.) The Cleveland open-cup tester may be manua
11、l or automated. If automated, the flash point instrument shall perform the test in accordance with Section 7. Figure 1Cleveland Open-Cup Apparatus ABDEFThermometerHeating PlateDiameterof OrificeGasorElectricHeatSourceGasSupplyDiameterof MetalBeadCDiameterof TubingOpen Cupwith Asphalt 2017 by the Ame
12、rican Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-2b T 48-3 AASHTO Millimeters Inches Min Max Min Max ADiameter 3.8 5.4 0.15 0.21 BRadius 152 nominal 6 nominal COutside Diameter 1.6 5.0 0.06 0.20 D 5.0 0.20 E 6.4, ap
13、proximately 0.25, approximately FInside Diameter 0.8 nominal 0.031 nominal Figure 1Cleveland Open-Cup Apparatus (continued) 4.1.1. Test CupCup made of brass or other metal of similar conductivity conforming to Figure 2. The cup may be equipped with a handle. Millimeters Inches Min Max Min Max A 67.5
14、 69 2.658 2.717 B 62.5 64.0 2.46 2.52 C 2.8 3.6 0.11 0.14 DRadius 4, approximately 0.16, approximately E 32.5 34 1.280 1.339 F 9 10 0.354 0.394 G 1.8 3.4 0.07 0.13 H 2.8 3.6 0.11 0.14 I 97 101 3.8 4.0 Figure 2Cleveland Open Cup ACFFillingMarkEIBGDH45 2017 by the American Association of State Highway
15、 and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-2b T 48-4 AASHTO 4.1.2. Heating PlatePlate that ensures the heat is evenly distributed over the bottom of the test cup and that extraneous heating to other surfaces is minimized. See Figure 3 for plat
16、e dimensions. Millimeters Inches Min Max Min Max A 6.4, nominal 0.25, nominal B 0.5 1.0 0.020 0.039 C 6.4, nominal 0.25, nominal DDiameter 54.5 56.5 2.15 2.22 EDiameter 69.5 70.5 2.736 2.776 FDiameter 150, nominal 6, nominal Figure 3Heating Plate 4.1.3. Heat SourceGas burner or electric heater cente
17、red under the opening of the heating plate with no local overheating. If using a gas burner, protect the flame from drafts using suitable shields that do not project above the top of the heating plate. 4.1.4. Thermometer HolderSupplied with the tester; it shall support the thermometer firmly in a ve
18、rtical position. 4.1.5. Heating Plate HolderSupport to hold the heating plate level and steady. 4.1.6. Ignition Source ApplicatorThe device for applying the test flame; may be of any suitable design, but the tip shall be 1.6 to 5.0 mm (0.06 to 0.20 in.) in diameter at the end and the orifice shall h
19、ave an approximate diameter of 0.8 mm (0.031 in.). The device for applying the test flame shall be so mounted to permit automatic duplication of the sweep of the test flame, the radius of swing being not less than 150 mm (6 in.) and the center of the orifice moving in a plane not more than 2.5 mm (0
20、.10 in.) above the cup. A bead having a diameter of 3.8 to 5.4 mm (0.15 to 0.21 in.) shall be mounted in a convenient position on the apparatus so the size of the test flame can be compared to it. 4.2. ThermometerAn ASTM 11C (11F) thermometer as prescribed in ASTM E1 with an accuracy of 0.2C (0.5F).
21、 The thermometer shall be calibrated according to the requirements specified in R 18. This thermometer shall be used to make all temperature measurements required by this method. FMetalThermalInsulationACEDB 2017 by the American Association of State Highway and Transportation Officials. All rights r
22、eserved. Duplication is a violation of applicable law.TS-2b T 48-5 AASHTO 4.2.1. The test thermometer may be replaced with an alternative thermometric device, provided the following requirements are met: 4.2.1.1. The thermometric device shall be mounted in the same position as the test thermometer i
23、t replaces. 4.2.1.2. The thermometric device shall 1) have a maximum scale error no greater than that of the test thermometer it replaces, 2) be capable of indicating temperature within 0.1C (0.2F), and 3) have the same temperature response. 4.2.1.3. The thermometric device shall be standardized at
24、the interval specified in R 18. Guidance for performing the standardization is given in ASTM E220 or E644. 4.3. Filling Level Gauge (optional)A device to aid in the proper adjustment of the sample level in the cup. It may be made of suitable metal with at least one projection, but preferably two, fo
25、r adjusting the sample level in the test cup to 9 to 10 mm (0.35 to 0.39 in.) below the top edge of the cup. A hole 0.8 mm (0.031 in.) in diameter, the center of which is located not more than 2.5 mm (0.10 in.) above the bottom edge of the gauge, shall be provided for use in checking the center posi
26、tion of the orifice of the test flame applicator with respect to the rim of the cup. (Figure 4 shows a suitable version.) Figure 4Filling Level Gauge 5. CALIBRATION AND STANDARDIZATION 5.1. The thermometer or thermometric device shall be standardized at the interval specified in R 18. 2017 by the Am
27、erican Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-2b T 48-6 AASHTO 5.2. The performance of the apparatus shall be verified at least once per year by determining the flash point of a known reference material. Run the
28、 test according to Section 7 on a certified flash point material. The certified flash point material shall have test results for T 48 or for ASTM D92. To be considered acceptable, the flash point shall be within 8.0C (14.4F) of the certified test result. If the test result is out of tolerance, check
29、 the apparatus for compliance with Section 4 and rerun with a new sample. 6. ASSEMBLY AND PREPARATION OF APPARATUS 6.1. The Cleveland open-cup tester shall be placed in a firm and level position on a solid, vibration-free table in a draft-free hood or flash room, or well toward the back of a draft s
30、hield. The top of the tester shall be shielded from strong light so that the flash may be easily seen. 6.2. The temperature measuring device shall be positioned with the bottom of the device being 6.4 1.0 mm (0.25 0.04 in.) above the bottom of the test cup and approximately halfway between the cente
31、r and the inside edge of the test cup on the side opposite the test flame applicator mounting position. 6.3. Follow manufacturers instructions for setting up the manual or the automated apparatus for operation. Set the automated tester to run the test in accordance with Section 7.3. 7. PROCEDURE 7.1
32、. Obtain the asphalt binder sample according to R 66. Heat the sample in its container with a loosely fitted cover in an oven not to exceed 163C (325F) for the minimum time necessary to ensure that the sample is completely fluid. Manually stir the sample but avoid incorporating air bubbles. 7.2. Fil
33、l the cup with material to be tested to the filling mark 9 to 10 mm (0.35 to 0.39 in.) below the rim of the cup. If the filling level gauge is used, fill the cup until the level of material just touches the pointers of the leveling device. Note 2The test sample should be at least 50C (90F) below the
34、 anticipated flash point. Note 3The sample cup may be filled away from the apparatus provided the thermometer is preset with the cup in place and the sample level is correct at the beginning of the test. A shim 6.4 mm (0.25 in.) thick is useful in obtaining the correction distance from the bottom of
35、 the bulb to the bottom of the cup. 7.3. Manual Flash Point Testing: 7.3.1. Light the test flame and adjust it to a diameter of 3.8 to 5.4 mm (0.15 to 0.21 in.). 7.3.2. For testing of a sample for which the expected flash point temperature is known, apply heat initially at such a rate that the tempe
36、rature indicated by the temperature-measuring device increases 10 to 20C (18 to 36F)/min. When the test specimen temperature is approximately 50C (90F) below the expected flash point, decrease the heat so that the rate of temperature rise during the last 28C (50F) before the flash point is 4 to 10C
37、(7 to 18F)/min. 7.3.3. At approximately 28C (50F) below the anticipated flash point and at successive 2C (5F) intervals, pass the ignition taper across the sample in a continuous motion so that the time consumed for each pass is 1 s. The center of the test flame must move in a horizontal plane not m
38、ore than 2.5 mm (0.10 in.) above the plane of the upper edge of the cup and pass in one direction only. At the time of the next test flame application, pass the test flame in the opposite direction of the preceding application. 2017 by the American Association of State Highway and Transportation Off
39、icials. All rights reserved. Duplication is a violation of applicable law.TS-2b T 48-7 AASHTO Note 4If a surface film forms on the sample, it is recommended that the film be moved to the side using a paperclip or spatula prior to application of the test flame. 7.3.4. From 28C (50F) below the anticip
40、ated flash point to the end of the test, take care to avoid disturbing the vapors in the test cup. 7.3.5. If a foam persists during that last 28C (50F) temperature rise below the anticipated flash point, end the test and disregard the results. 7.3.6. For testing of a sample for which the expected fl
41、ash point temperature is not known, heat the sample to the temperature used for pouring in Section 7.1. Continue heating the test specimen at 4 to 10C (7 to 18F)/min and testing the material every 2C (5F) as described in Section 7.3.2 until the flash point is obtained. 7.3.7. Record, as the observed
42、 flash point, the temperature read on the thermometer at the time the test flame application causes a distinct flash in the interior of the test cup. Note 5The application of the test flame may cause a halo or enlargement of the test flame. This is not considered the flash point. A large flame that
43、propagates on the surface denotes that the flash point has been reached. 7.4. Automated Flash Point Testing: 7.4.1. If necessary, light the test flame, and adjust it to a diameter of 3.8 to 5.4 mm (0.15 to 0.21 in.). Note 6Some automated apparatus can light and adjust the test flame automatically, a
44、nd some automated apparatus pass the test flame in one single direction. 7.4.2. Start the automated apparatus according to the manufacturers instructions. The automated apparatus shall conduct the procedure as required in Section 7.3. 7.4.3. Record, as the flash point, the temperature read on the th
45、ermometer at the time the test flame application causes a distinct flash in the interior of the test cup. 8. CALCULATIONS 8.1. Observe and record the ambient barometric pressure in the laboratory at the time of the test. If the barometric pressure varies from 101.3 kPa (760 mmHg), calculate the corr
46、ected flash point as follows: Corrected flash point (C) = C + 0.25 (101.3 A) (1) Corrected flash point (F) = F + 0.06 (760 B) (2) Corrected flash point (C) = C + 0.033 (760 B) (3) where: C = observed flash point, C; A = ambient barometric pressure, kPa; F = observed flash point, F; and B = ambient b
47、arometric pressure, mmHg. 9. REPORT 9.1. Report the corrected flash point, in degrees Celsius or Fahrenheit, as the “Cleveland Open-Cup Flash Point.” Report flash point to the nearest whole number. 2017 by the American Association of State Highway and Transportation Officials. All rights reserved. D
48、uplication is a violation of applicable law.TS-2b T 48-8 AASHTO 10. PRECISION AND BIAS 10.1. PrecisionCriteria for judging the acceptability of test results for the flash point of asphalt binders obtained by this method are given in Table 1. 10.1.1. Single-Operator Precision (Repeatability)The figur
49、es in Column 2 of Table 1 are the standard deviations that have been found to be appropriate for the conditions of test described in Column 1. Two results obtained in the same laboratory, by the same operator using the same equipment, in the shortest practical period of time, should not be considered suspect unless the difference in the two results exceeds the values given in Table 1, Column 3. 10.1.2. Multilaboratory Precision (Reproducibility)T
