1、Standard Method of Test for Force Ductility Test of Asphalt Materials AASHTO Designation: T 300-11 American Association of State Highway and Transportation Officials 444 North Capitol Street N.W., Suite 249 Washington, D.C. 20001 TS-2a T 300-1 AASHTO Standard Method of Test for Force Ductility Test
2、of Asphalt Materials AASHTO Designation: T 300-11 1. SCOPE 1.1. The force ductility of an asphalt material is determined by measuring the tensile stress induced on a specimen when two ends of a briquet specimen of the material are pulled apart at 5 cm/min (2 in./min) and at a specified temperature.
3、Unless otherwise specified, the test shall be performed at a temperature of 4.0 0.5C (39.2 1.0F) and a speed of 5 cm/min (2 in./min) 5.0 percent. The test is designed primarily for polymer-modified emulsions. 1.2. The values stated in SI units are to be regarded as the standard. 1.3. This test may i
4、nvolve 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 of this standard to establish appropriate safety and health practices and determine the applicability of regulatory li
5、mitations prior to use. 2. REFERENCED DOCUMENTS 2.1. AASHTO Standard: M 316, Polymer-Modified Cationic Emulsified Asphalt 2.2. ASTM Standards: E1, Standard Specification for ASTM Liquid-in-Glass Thermometers E77, Standard Test Method for Inspection and Verification of Thermometers E220, Standard Tes
6、t Method for Calibration of Thermocouples By Comparison Techniques E644, Standard Test Methods for Testing Industrial Resistance Thermometers 3. SIGNIFICANCE AND USE 3.1. The force ductility test is an indicator of the presence of polymer in an asphalt material. 3.2. When testing CRS-2P, a polymer-m
7、odified cationic emulsified asphalt specified in M 316, perform the test at a temperature of 4C (39F) and a speed of 5 cm/min (2 in./min). The test is performed on the residue from evaporation. 4. APPARATUS 4.1. MoldsThe mold shall be similar in design to that shown in Figure 1 and made of brass. Th
8、e dimensions of the assembled mold shall be as shown in Figure 1 with the permissible variations indicated. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-2a T 300-2 AASHTO 4.2. Base PlateThe base pl
9、ate shall be made of nonabsorbent material, of sufficient thickness to prevent deformation, and of a sufficient size to hold from one to three molds. The plate shall be uniformly flat to ensure that the bottom surfaces of each mold will touch it throughout. 4.3. Water BathThe water bath shall be mai
10、ntained at the specified test temperature, varying not more than 0.5C (1.0F) from this temperature. The volume of water shall not be less than 10 L (2.6 gal). The depth of water shall not be less than 50 mm (2 in.) and such that the mold can be immersed to a depth of not less than 25 mm (1 in.). The
11、 water in the bath shall be free from oil and slime or other organic growth. 4.4. ThermometersFor tests at 4.0C (39.2F), use an ASTM Thermometer No. 63C (63F) as specified in ASTM E1 to measure the temperature of the water bath and the temperature of the water in the testing machine. For tests at ot
12、her temperatures, use ASTM thermometers of an appropriate range and accuracy equal to that of the No. 63. Because the accuracy of the test results is dependent upon closely controlled conditions of temperature, the thermometers should be standardized in accordance with ASTM E77. An equivalent thermo
13、metric device that has been standardized in accordance with ASTM E220 or E644 may be used. Notes: 1. All dimensions in mm 2. Material: 360 brass 3. Finish: None Figure 1Mold Assembly 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a
14、violation of applicable law.TS-2a T 300-3 AASHTO 4.5. Testing MachineFor pulling the briquet of asphalt material apart, any apparatus may be used that is constructed such that the specimen will be continuously immersed in water, as specified in Section 5.4, while the two clips are pulled apart at a
15、uniform speed, as specified, without undue vibration. 4.6. HeaterAn oven or hot plate, heated by electricity or gas, may be used to melt the asphalt material. 4.7. ContainerAny suitable container may be used to hold the asphalt material while it is being melted. 4.8. TrimmerAny convenient implement,
16、 such as a putty knife or spatula, may be used provided that the cutting edge is straight and at least 38 mm (11/2in.) wide. 4.9. Calibrated Force AdapterA stainless steel platform that incorporates a linear variable differential transformer (LVDT) sensor for measuring tensile force accurate to 0.04
17、 N (0.01 lb). The unit is designed to utilize the existing pins on a ductility machine. 4.10. Digital IndicatorA power supply and digital display in newtons (pounds) that serves the LVDT sensor on the force adapter. Includes a standard 0- to 5-VDC analog output for interfacing with a chart recorder,
18、 computer, or other readout. 4.11. Chart Recorder (Optional)Records output of the digital indicator through the 0- to 5-VDC analog output. 5. PROCEDURE 5.1. Preparation of ApparatusAssemble the mold on the base plate. To prevent the asphalt material from sticking, coat the surface of the plate and t
19、he interior surfaces of Sides a and a (as indicated in Figure 1) with a suitable release agent (Note 1). Note 1Mixtures of glycerin and dextrin or talc (3 g of glycerin to about 5 g of dextrin or talc), Dow-Corning Silicone Stop-Cock Grease, or castor oil and Versamid 900 100:1 mixture by mass heate
20、d to 204 to 232C (400 to 450F) and stirred until it is homogeneous have proven suitable. Other release agents may be used provided the results obtained are comparable to those obtained when using one of the above. 5.2. Molding Test SpecimensHeat the sample with care to prevent local overheating unti
21、l it has become sufficiently fluid to pour. After thorough stirring, pour the asphalt material into the mold, taking care not to entrain any air bubbles. Pour the material in a thin stream back and forth from end to end until the mold is more than level full. In filling the mold, take care not to di
22、sarrange the parts of the mold and distort the briquet. Let the mold and contents cool to room temperature for 30 to 40 min, and then place the base plate and filled mold in the water bath maintained at the specified test temperature for 30 min. Remove the base plate and filled mold from the water b
23、ath, and with a hot trimmer, cut off the excess asphalt material so that the mold is just level full. Take care during the trimming operation that the specimen is not pulled away from the base plate or from the side pieces of the mold. 5.3. Keeping Specimen at Standard TemperaturePlace the base plat
24、e and filled mold in the water bath or testing machine and keep them at the specified temperature for 85 to 95 min. The test will be conducted at the specified temperature. Remove the briquet from the plate, detach the side pieces, and immediately test the briquet. 2015 by the American Association o
25、f State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-2a T 300-4 AASHTO 5.4. TestingAt the start of the test, the water in the tank of the testing machine shall cover the specimen both above and below by not less than 25 mm (1 in.). Attach
26、the clips to the pins or hooks of the force adapter and the testing machine, and pull the clips apart at the specified rate of speed until the specified minimum ductility is met, the briquet ruptures, or the limit of travel of the machine is reached. If necessary, adjust the specific gravity of the
27、liquid in the testing machine so that the asphalt material neither comes to the surface nor touches the bottom of the bath at any time during the test by adding a solute that does not interfere with the test (Note 2). Measure and record the distance through which the clips have been pulled. Note 2So
28、lutes such as sodium chloride, methyl alcohol, or ethylene glycol have been used successfully. 6. REPORT 6.1. A normal test is one in which the material between the two clips is pulled to a point where minimum ductility is met, rupture occurs at the point where the thread has practically no cross-se
29、ctional area, or until the capacity of the machine is reached. If the material comes in contact with the surface of the water or the bottom of the bath, the test shall not be considered normal. 6.2. A normal test will produce data that, when plotted, will result in a graph showing two peaks (f1, f2)
30、. Locate the two peaks on the graph of the data. The second peak will be less than the initial peak. If a readily definable second peak is not apparent, use the force at the minimum ductility (if specified), at the point of rupture, or at 30 cm (11.8 in.) as the second peak (f2). The force ratio is
31、defined as the force at the second peak (f2) divided by the force at the initial peak (f1). 6.3. Report the force ratio to the nearest 0.1. 7. PRECISION AND BIAS 7.1. PrecisionThe research required to develop precision estimates has not been conducted. 7.2. BiasThis test method has no bias because the values determined can be defined only in terms of this test method. 8. KEYWORDS 8.1. Asphalt; ductility; force ductility; force ratio. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.
