1、Standard Method of Test for Polymer Content of Polymer-Modified Emulsified Asphalt Residue and Asphalt Binders AASHTO Designation: T 302-15 American Association of State Highway and Transportation Officials 444 North Capitol Street N.W., Suite 249 Washington, D.C. 20001 TS-2a T 302-1 AASHTO Standard
2、 Method of Test for Polymer Content of Polymer-Modified Emulsified Asphalt Residue and Asphalt Binders AASHTO Designation: T 302-15 1. SCOPE 1.1. This test method is used to determine the percent concentration of a Styrene-Butadiene-Rubber (SBR), Styrene-Butadiene (SB), or Styrene-Butadiene-Styrene
3、(SBS) polymer in a polymer-modified asphalt binder or emulsified asphalt residue. By using the infrared spectrum and the principles of Beers Law, the polymer content of the asphalt material can be determined. 1.2. This standard involves hazardous materials, operations, or equipment. This standard do
4、es 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 limitations prior to use. 2. REFERENCED DOCUMENTS 2.1. AASHTO Standar
5、ds: M 231, Weighing Devices Used in the Testing of Materials T 59, Emulsified Asphalts 3. APPARATUS 3.1. BalanceConforming to the requirements of M 231, Class G 1. 3.2. ContainersFor blending the asphalt material with polymermetal 1-pt (0.47-L) cans with lids are suitable. 3.3. Variable-Speed Sheari
6、ng Mixer. 3.4. Heating Coil with Variable Rheostat. 3.5. ThermometerFor determining temperatures between 4 and 305C (40 and 580F). 3.6. High-Temperature Vacuum Oven (if necessary for removal of residual moisture). 3.7. Infrared Spectrophotometer or Fourier Transform Infrared SpectrometerCapable of r
7、ecording spectra in the 1800-to-600-cm1region. 3.8. Infrared WindowsPolished sodium chloride or potassium chloride windows, or other suitable medium for casting of infrared specimens. If testing by use of the attenuated total reflectance (ATR) method, an ATR accessory and the appropriate crystal are
8、 necessary. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-2a T 302-2 AASHTO 3.9. Testing by Solvent-Diluted Method: 3.9.1. Glass Vial with Leak-Resistant Top. 3.9.2. Eyedroppers. 3.9.3. Infrared Hea
9、t Lamp. 3.9.4. Solvent. Note 1Trichloroethane, technical grade, and tetrahydrofuran (THF) have been shown to be suitable solvents that do not interfere with the infrared spectrum. Other appropriate solvents may be used. 3.10. Testing by ATR Method: 3.10.1. Release Paper (wax paper or other suitable
10、medium). 3.10.2. SpatulaAppropriate for spreading hot asphalt binder or emulsified asphalt residue. 3.10.3. SolventAppropriate for removal of the test material from the infrared window. 4. PREPARATION OF CONTROL SAMPLES 4.1. Prepare a series of standards to cover the range from 0 to 5 percent weight
11、-to-weight (w/w) polymer (rubber solids) according to Equation 1. Note 2The standards are prepared on a w/w percentage. This percentage is based on the solids weight of the polymer and the weight of the base asphalt binder or the emulsified asphalt residue. If the polymer is in an emulsified form or
12、 the standards are being made with an asphalt emulsion, an accurate determination of the rubber solids or percent asphalt residue must be made in order to prepare accurate standards. 4.1.1. This equation makes the assumption that there is no polymer contained in the base asphalt binder or emulsified
13、 asphalt (A) and that all solids in the polymer modifier are polymer (D): ( )( )( )( )( )100B ACEBD=(1) where: E = mass of polymer modifier, g; B = percent polymer in the standard (e.g., 1, 2, 3, etc.); A = mass of the base asphalt binder or emulsified asphalt, g; C = percent asphalt residue (determ
14、ined by T 59 for emulsified asphalt, otherwise 100); and D = percent rubber solids in polymer modifier (determined for emulsified polymers, otherwise 100). 4.2. For each standard, add the calculated amount of asphalt binder or emulsified asphalt needed into a container suitable for mixing. Allow suf
15、ficient material to be able to thoroughly blend each standard. 4.3. Heat the asphalt binder until it is fluid at a temperature not to exceed 163C (325F). An emulsion should be heated to 82 1C (180 2F). 2015 by the American Association of State Highway and Transportation Officials.All rights reserved
16、. Duplication is a violation of applicable law.TS-2a T 302-3 AASHTO 4.4. While maintaining heat and with the mixer in operation, slowly add the calculated amount of polymer modifier for each standard to the container of base asphalt binder or emulsified asphalt. Allow the materials to mix thoroughly
17、. Note 3The addition of solid polymers may require extensive heating and shearing. A gradual addition of the material may be necessary. Addition of emulsified polymers in heated asphalt binders should be performed slowly to prevent boilover. 5. PREPARATION OF POLYMER SAMPLES AND TESTING BY SOLVENT-D
18、ILUTED METHOD 5.1. Heat the asphalt binder until it is fluid, at a temperature not to exceed 163C (325F). An emulsion should be heated to 82 1C (180 2F) while stirring it to achieve a homogeneous state. 5.2. After the sample is thoroughly mixed, place approximately 1 g of the sample in a glass vial.
19、 5.3. If there is any residual moisture in the sample, place the vial in a vacuum oven set at approximately 20 mmHg and 104 2C (220 4F) until constant mass is achieved. 5.4. After drying, remove the vials from the oven and cool them to room temperature. 5.5. Dilute the contents of each glass vial wi
20、th approximately 10 mL (0.3 oz) of the solvent. 5.6. Shake the vial until the sample is completely dissolved in the solvent. 5.7. Place drops of each solvent-diluted material on a prepared infrared window using an eyedropper. Ensure that an even layer is placed on the window. Note 4Five to nine drop
21、s of an asphalt material diluted 1 g to 10 mL (0.3 oz) on a 38-by- 19-mm (1.5-by-0.75-in.) window has been shown to produce an adequate film thickness. Use of the ratio of the specified peak for the polymer to the peak for the asphalt negates any deviations due to film thickness. 5.8. Allow the solv
22、ent to evaporate at room temperature, or place the window under a heat lamp for approximately 10 min to drive off any residual solvent. Complete evaporation of any residual solvent will prevent the analysis of misleading spectra. 6. PROCEDURETESTING BY ATR METHOD 6.1. Heat the asphalt binder, or, he
23、at the asphalt residue from evaporation (T 59) when testing emulsified asphalt, until it is fluid at a temperature not to exceed 163C (325F) while stirring it to achieve a homogeneous state. 6.2. Pour the heated material, spreading it with a spatula, on a piece of release paper cut slightly larger t
24、han the face of an ATR crystal. Use enough material to result in a layer that will cover the face of the crystal. A thin film will make cleanup of the crystal easier. An asphalt thickness on the paper of about 1 mm (0.04 in.) is sufficient. 6.3. Prepare an ATR crystal following the manufacturers gui
25、delines. 6.4. Allow the material to cool for several minutes prior to affixing the asphalt surface in direct contact with the top of the face of the prepared ATR crystal. Apply finger pressure to the top of the asphalt material to push out any air bubbles. The material must make complete contact wit
26、h the crystal without any bubbles. Examination of the underside of the crystal may expose any bubbles or points of noncontact. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-2a T 302-4 AASHTO Note 5F
27、ollow the manufacturers guidelines for treatment of the crystal. Placement of hot material or too much pressure on the face of the crystal may cause it to crack. 7. DATA COLLECTION AND ANALYSIS 7.1. Analysis of the Standards: 7.1.1. Using either the solvent-diluted or ATR method, acquire spectra on
28、the prepared windows or crystal for each standard. Collection of a background spectrum is recommended prior to sample analysis. 7.1.2. Integrate the proper peak. Note 6The infrared spectrometer may be equipped with software that will quantify a specific peak or multiple peaks by using peak height or
29、 peak area. It may be necessary to correct the spectral baselines for offset or tilt. 7.1.2.1. For the solvent-diluted method, determine the absorbance at 965 cm1for the polymer modifier (SBR, SB, or SBS) and at 1375 cm1for the base asphalt binder or emulsified asphalt residue on each standard. Divi
30、de the value of the peak at 965 cm1(A1) by the peak at 1375 cm1(A2) to obtain the absorbance ratio of the relative peak values (A1/A2) of each standard. See the example in Figure 1. Figure 1Infrared Scan of a Polymer-Modified Asphalt Material 7.1.2.2. For the ATR method, evaluate the peak area at 96
31、5 cm1for the polymer modifier (SBR, SB, or SBS). In the ATR method, the spectrum obtained is independent of the sample thickness, so it will not be necessary to integrate the peak at 1375 cm1. 7.1.3. Plot the absorbance ratio of the relative peak values (A1/A2) determined in the solvent-diluted meth
32、od versus the corresponding polymer content or plot the peak area determined in the ATR method versus the corresponding polymer content, of each standard. Perform a first-order curve fit on the data to generate a standard curve. See the example for the solvent-diluted method in Table 1 and Figure 2.
33、 1375 cm1(A2)965 cm1(A1)Absorbance Ratio = A1/A2600800100012001400160018000.00.10.20.30.40.5Wave Numbers (cm1)AbsorbanceMattson GL- 3025Resolution: 4.0Gain: 1 Scans: 32 Iris: 0 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violat
34、ion of applicable law.TS-2a T 302-5 AASHTO Table 1Typical Data for Standard Curve Development for Solvent-Diluted Method Standard, % Polymer Absorbance Ratio (A1/A2) 0 0.02 1 0.065 2 0.11 3 0.155 4 0.20 5 0.245 Figure 2Polymer Content versus Absorbance Ratio (A1/A2)Solvent-Diluted Method 7.2. Analys
35、is of Sample: 7.2.1. Analyze each sample using the applicable sections for the selected method (i.e., solvent-diluted or ATR) in Sections 7.1.1 through 7.1.2.2, and obtain the relative absorbance ratio (A1/A2) or peak area of the sample as appropriate. 7.2.2. Using the standard curve information, ca
36、lculate the polymer content of the sample. 8. REPORT 8.1. The values determined for the polymer content shall be reported to the nearest 0.1 percent. 9. PRECISION AND BIAS 9.1. Information is currently not available to develop a precision and bias statement. 10. KEYWORDS 10.1. Emulsified asphalt residue; polymer content; polymer-modified asphalt binder; SB; SBR; SBS. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.
