1、Standard Method of Test for Flash Point of Asphalt Binder by Cleveland Open Cup AASHTO Designation: T 48-181Technical Section: 2b, Liquid Asphalt Release: Group 3 (August) American Association of State Highway and Transportation Officials 444 North Capitol Street N.W., Suite 249 Washington, D.C. 200
2、01 TS-2b T 48-1 AASHTO Standard Method of Test for Flash Point of Asphalt Binder by Cleveland Open Cup AASHTO Designation: T 48-181Technical Section: 2b, Liquid Asphalt Release: Group 3 (August) 1. SCOPE 1.1. This method covers the procedure for the determination of flash point of asphalt binder by
3、the Cleveland open-cup apparatus. 1.2. This test method is applicable to asphalt binder with flash point between 219C (426F) 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). 1.3. The
4、 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 safety and
5、 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, Flash Point
6、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 E220, Stan
7、dard Test Method for Calibration of Thermocouples By Comparison Techniques E644, Standard Test Methods for Testing Industrial Resistance Thermometers 2018 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-2
8、b 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, 2004. 3.
9、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 test flame
10、 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 the dimensions shown and have the additional characteristics as noted. (See Figure 1.) The Cleveland open-cup tester may be manual or autom
11、ated. 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 2018 by the American Asso
12、ciation 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, approximatel
13、y 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 69 2.66 2
14、.72 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 1.28 1.34 FDistance from the top of the cup 9 10 0.35 0.39 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 2018 by the American Association
15、of State Highway 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 F
16、igure 3 for plate 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 2.74 2.78 FDiameter 150, nominal 6, nominal Figure 3Heating Plate 4.1.3. Heat SourceGas burner or electri
17、c heater centered 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
18、firmly in a vertical 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 o
19、rifice shall have 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
20、than 2.5 mm (0.10 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 o
21、f 0.2C (0.5F). 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 2018 by the American Association of State Highway and Transportation Officials
22、. All rights reserved. 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
23、 thermometer it 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 st
24、andardized at 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 pref
25、erably two, for 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 t
26、he center position 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.
27、2018 by the American 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 mat
28、erial. Run the 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 to
29、lerance, check the apparatus for compliance with Section 4 and rerun with a new sample. 6. ASSEMBLY AND PREPARATION OF APPARATUS 6.1. The cup shall be cleaned prior to each use and any remaining residue from previous tests shall be removed. Solvents and steel wool are suitable for this purpose. The
30、test cup shall be dried until there is no remaining water or solvent in the cup prior to use. Note 2A hot plate, oven, or open flame is useful in ensuring that the cup is completely dry before use. 6.2. The Cleveland open-cup tester shall be placed in a firm and level position on a solid, vibration-
31、free table. The device shall be placed in a draft-free location or shall be shielded from any drafts which may impact testing. The top of the tester shall be shielded from strong light so that the flash may be easily seen. 6.3. The temperature measuring device shall be positioned with the bottom of
32、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 center and the inside edge of the test cup on the side opposite the test flame applicator mounting position. 6.4. Follow manufacturers instructions for setting up the manual or the auto
33、mated apparatus for operation. Set the automated tester to run the test in accordance with Section 7.3. 7. PROCEDURE 7.1. 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 necessa
34、ry to ensure that the sample is completely fluid. Manually stir the sample but avoid incorporating air bubbles. 7.2. Fill 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
35、 material just touches the pointers of the leveling device. Note 3The test sample should be at least 50C (90F) below the anticipated flash point. Note 4The 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
36、 beginning of the test. A shim 6.4 mm (0.25 in.) thick is useful in obtaining the correction distance from the bottom of 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
37、 of a sample for which the expected flash point temperature is known, apply heat initially at such a rate that the temperature 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 poi
38、nt, decrease the heat so that the rate of temperature rise during the last 28C (50F) before the flash point is 4 to 10C (7 to 18F)/min. 2018 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-2b T 48-7 AASHT
39、O 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 more than 2.5 m
40、m (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. Note 5If a surface film forms on the sample, it is recommended that the film be moved
41、to the side using a paperclip or spatula prior to application of the test flame. 7.3.4. From 28C (50F) below the anticipated 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 a
42、nticipated flash point, end the test and disregard the results. 7.3.6. For testing of a sample for which the expected flash 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 th
43、e material every 2C (5F) as described in Section 7.3.2 until the flash point is obtained. 7.3.7. Record, as the observed 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 6The application of the t
44、est flame may cause a halo or enlargement of the test flame. This is not considered the flash point. A large flame that 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
45、of 3.8 to 5.4 mm (0.15 to 0.21 in.). Note 7Some automated apparatus can light and adjust the test flame automatically, and 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 s
46、hall conduct the procedure as required in Section 7.3. 7.4.3. Record, as the 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. 8. CALCULATIONS 8.1. Observe and record the ambient barometric pressure in
47、 the laboratory at the time of the test. If the barometric pressure varies from 101.3 kPa (760 mmHg), calculate the corrected 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)
48、where: C = observed flash point, C; A = ambient barometric pressure, kPa; F = observed flash point, F; and B = ambient barometric pressure, mmHg. 2018 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-2b T
49、48-8 AASHTO 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. 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 figures in Column 2 of Table 1
