1、Standard Method of Test for Measuring Adhesion of Hot-Poured Asphalt Crack Sealant Using Direct Adhesion Tester AASHTO Designation: T 370-171Technical Section: 4e, Joints, Bearings, and Geosynthetics Release: Group 2 (June 2017) American Association of State Highway and Transportation Officials 444
2、North Capitol Street N.W., Suite 249 Washington, D.C. 20001 TS-4e T 370-1 AASHTO Standard Method of Test for Measuring Adhesion of Hot-Poured Asphalt Crack Sealant Using Direct Adhesion Tester AASHTO Designation: T 370-171Technical Section: 4e, Joints, Bearings, and Geosynthetics Release: Group 2 (J
3、une 2017) 1. SCOPE 1.1. The direct adhesion test is used to determine the adhesion strength of hot-poured asphalt crack sealant at the application temperature as specified in MP 25 and PP 85. 1.2. The adhesion test is a test of fracture. The object of the test is to apply tensile forces to the inter
4、face between sealant and aluminum end pieces. Sealant is confined between two half-cylindrical aluminum end pieces. The applied force and displacement can be recorded as functions of time. Energy required to break the bond can be calculated by measuring the area under the load-displacement curve. Th
5、is energy can be considered a measure of bonding. In addition, the maximum force to failure can be reported as adhesion strength. 1.3. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to estab
6、lish and follow appropriate health and safety practices and determine the applicability of regulatory limitations prior to use. 2. REFERENCED DOCUMENTS 2.1. AASHTO Standards: MP 25, Performance-Graded Hot-Poured Asphalt Crack Sealant PP 85, Grading or Verifying the Sealant Grade (SG) of a Hot-Poured
7、 Asphalt Crack Sealant T 314, Determining the Fracture Properties of Asphalt Binder in Direct Tension (DT) T 367, Accelerated Aging of Hot-Poured Asphalt Crack Sealant Using a Vacuum Oven 2.2. ASTM Standards: D5167, Standard Practice for Melting of Hot-Applied Joint and Crack Sealant and Filler for
8、Evaluation E1, Standard Specification for ASTM Liquid-in-Glass Thermometers E77, Standard Test Method for Inspection and Verification of Thermometers 3. TERMINOLOGY 3.1. Definitions: 2017 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a
9、 violation of applicable law.TS-4e T 370-2 AASHTO 3.1.1. adhesionthe maximum force and energy required to separate hot-poured asphalt crack sealant from a standard substrate. 3.1.2. hot-poured asphalt crack sealanthot-poured modified asphaltic material used in pavement cracks and joints. Note 1Based
10、 on the references, hot-poured asphalt crack sealant is typically applied at a temperature of 160C or above. 4. SUMMARY OF METHOD 4.1. Hot-poured asphalt crack sealant material is homogenized, following the procedure given in ASTM D5167. For each test including four replicates, cut 40 g of sealant a
11、nd heat to the manufacturers recommended pouring temperature. Sealant will be poured in the mold placed between the two half-cylindrical aluminum end pieces. The mold confines the sealant at the bottom and between the two aluminum end pieces at the sides. 5. SIGNIFICANCE AND USE 5.1. This procedure
12、is designed to measure the adhesion of hot-poured asphalt crack sealant to aggregate. 5.2. Hot-poured asphalt crack sealant must be homogenized (ASTM D5167) before measuring the adhesion by this method. 6. APPARATUS 6.1. Direct Tension Test (DTT) DeviceModified T 314 Direct Tension Tester (DTT) mach
13、ine. 6.2. Test ChamberTest Chamber that can reach 40 0.5C. 6.3. Laboratory OvenAny standard laboratory oven capable of producing and maintaining temperatures ranging from 170 to 193C 0.5C. 6.4. Release AgentA proper release agent to prevent the crack sealant from sticking to the mold. A silicon-base
14、d release agent is recommended. 6.5. Test Specimen Mold SetupsFour aluminum molds. 7. HAZARDS 7.1. Standard laboratory caution should be used in handling hot asphalt crack sealant in accordance with ASTM D5167, and when using the direct tension tester (DTT). Required safety procedures should be foll
15、owed when chemical agents are used. 8. PREPARATION OF APPARATUS 8.1. The DTT bath must be adjusted to a specific temperature. The sitting posts must be leveled to function properly. 2017 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a
16、violation of applicable law.TS-4e T 370-3 AASHTO 9. CALIBRATION AND STANDARDIZATION 9.1. Temperature of the ovens should be calibrated according to each users quality assurance program. 9.2. Temperature of the chiller should be calibrated according to each users quality assurance program. 9.3. Therm
17、ometer (temperature detector)Verify the calibration of the temperature-sensing device to 0.1C every 6 months in accordance with ASTM E1 and ASTM E77, as applicable. 10. PREPARATION OF SAMPLES AND TEST SPECIMENS 10.1. All hot-poured asphalt crack sealants to be tested must undergo accelerated aging i
18、n accordance with T 367. It is recommended that a minimum of 70 g of hot-poured asphalt crack sealant be prepared for a set of tests. 10.2. Once aged, hot-poured asphalt crack sealant should be molded, cooled, and stored for later use. To store the sealant, it is recommended that a can or plastic-li
19、ned box be used as a container. The mold must be of sufficient size that the sealant depth is no greater than 100 mm to allow for rapid cooling. 10.3. Adjust the ovens temperature to recommended pouring temperature for the sealant being tested. 10.4. Turn on the DTT machine, load the program, and co
20、ol the chiller to test temperature. 10.5. Place a half cylinder of aluminum end piece in each grip and tighten it (Figure 1). Figure 1Placing Each End Piece in One Grip and Tightening It 10.6. Coat the specimen-forming surfaces of the two mold side plates of the aluminum mold with the release agent.
21、 The coating shall be applied so as to produce a thin uniform film on the metal surface such that no part of the metal surface is exposed (see Figure 2). 2017 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.
22、TS-4e T 370-4 AASHTO Figure 2Spraying Release Agent on the Mold 10.7. Assemble the setup, which is composed of an aluminum end piece on each side and an aluminum mold in between (Figure 3). Wrap a rubber band around the setup to keep all the components in place (Figure 4). Figure 3Placing Two End Pi
23、eces on the Mold Figure 4Using a Rubber Band and Holding the Assembly in Place 2017 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-4e T 370-5 AASHTO 10.8. Place the notch on the edge of one of the alumin
24、um end pieces. 10.9. Prepare a can of sealant by cutting 35 g of homogenized sealant for each set of four samples. 10.10. Place the can in the oven for 15 min (Figure 5). Remove can from the oven, stir the sealant thoroughly, and place it back in the oven for another 15 min. Figure 5Heating 35 g of
25、Homogenized Sealant at Recommended Pouring Temperature for 30 min 10.11. Remove the can from the oven, stir the sealant thoroughly, and pour into all the assembled setups. Use four replicates for each sealant. Care should be taken in filling up the molds to prevent any trapped air bubbles in the sam
26、ple (Figure 6). Figure 6Removing the Sealant from the Oven, Mixing Thoroughly, and Pouring It in the Mold from One Corner 2017 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-4e T 370-6 AASHTO 10.12. Let
27、samples set for 1 h at room temperature (Figure 7). Figure 7Letting Sealant Set for 1 h at Room Temperature 10.13. Trim the excessive sealant away with a hot spatula. Move spatula once over and parallel to the interface of the sample. Trimming direction shall not be changed during trimming. Use a we
28、ll- heated spatula to prevent any shearing of the sealant (Figure 8). Figure 8Trimming the Extra Sealant Away Using a Heated Spatula 2017 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-4e T 370-7 AASHTO
29、10.14. Use two tongs to grab the plate underneath the specimen and place the specimens in the cooling bath (Figure 9). Figure 9Grabbing the Base Plate with Two Tongs, and Placing It in the Cooling Bath 10.15. Remove the plates underneath each specimen (Figure 10), and leave the specimens in the bath
30、 for 15 min (Figure 11). Figure 10Removing the Base Plates 2017 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-4e T 370-8 AASHTO Figure 11Leaving the Specimens in the Cooling Bath for 15 min 10.16. Remov
31、e one specimen at a time from the bath (Figure 12) and place it on a flat surface. Figure 12Holding Its Center with Tongs and Removing One Specimen at a Time 10.17. Flip the specimen on a flat surface (Figure 13), remove the rubber band (Figure 14), and keep the two end pieces in place using the ind
32、ex fingers (Figure 15). Remove the mold with your thumb. Figure 13Flipping the Specimen on a Flat Surface 2017 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-4e T 370-9 AASHTO Figure 14Removing the Rubbe
33、r Band Figure 15Removing the Mold While Keeping the Two End Pieces in Place 10.18. Flip back the specimen, and push back the notch horizontally until it comes off (Figure 16). Figure 16Flipping Back the Specimen and Pushing the Notch Horizontally Until It Comes Off 2017 by the American Association o
34、f State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-4e T 370-10 AASHTO 10.19. Place the specimen back in the bath (Figure 17). Figure 17Grabbing the Specimen from Two Corners and Placing It Back in the Bath 10.20. Repeat steps 10.16 thro
35、ugh 10.19 until all specimens are demolded. 10.21. Leave the specimens for 45 min in the bath prior to testing (Figure 18). Figure 18Leaving the Specimens for 45 min in the Bath 10.22. Open the DTT test builder program, adjust the machine so the sample can sit freely on the posts, and place the spec
36、imen on the posts (Figure 19A). Care should be taken not to disturb the specimen. 2017 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-4e T 370-11 AASHTO 10.23. Run the test and record the data (Figures 1
37、9B and 19C). A B C Figure 19 Mounting the Specimen in the DTT Machine, Running the Test to Completion, and Removing the Sample after Test Completion 11. CALCULATION OF RESULTS 11.1. Find the maximum load (Pmax) to failure and its correspondent displacement. 11.2. Find the bonding energy (E), by calc
38、ulating the area under the load-displacement curve up to the maximum load and dividing it by the cross-sectional area of the aluminum end piece. 11.3. Report the Pmaxand E as the selection thresholds. 12. REPORT 12.1. Report the following information: 12.1.1. Sealant identification and supplier, 12.
39、1.2. Lot number, 12.1.3. Date received, 12.1.4. Date of apparent viscosity measurement, 12.1.5. Recommended pouring temperature, 12.1.6. Safe heating temperature, 12.1.7. Any deviations from test temperature, 12.1.8. Maximum load (Pmax), nearest N, and 12.1.9. Bonding energy, nearest 1 J/m2. 2017 by
40、 the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-4e T 370-12 AASHTO 13. PRECISION AND BIAS 13.1. Single-Operator Precision (Repeatability)The results obtained in the same laboratory, by the same operator usi
41、ng the same equipment, in the shortest practical period of time, should not be considered suspect unless the difference in the two results, expressed as a percent of their mean, exceeds the value given in Table 1. Table 1Precision Estimates Condition Coefficient of Variation (1s%)aSingle-operator pr
42、ecision: Average peak load (N) 19.3 aThe precision estimate given in Table 1 is based on the analysis of test results from seven sealants with a wide range of rheological properties. The data analyzed include results from two operators in the same laboratory who conducted each test in four replicate
43、s. 14. KEYWORDS 14.1. Adhesion; bond; crack; fillers; hot-poured asphalt crack sealant; joint. 15. REFERENCES 15.1. Al-Qadi, I. L., J. F. Masson, E. Fini, S. H. Yang, and K. K. McGhee. Development of Performance-Based Guidelines for Selection of Bituminous-Based Hot-Poured Pavement Crack Sealant: An
44、 Executive Summary Report. VTRC 09-CR7. Virginia Transportation Research Council, Charlottesville, VA, 2009. Available online at http:/vtrc.virginiadot.org/PubDetails.aspx?PubNo=09-CR7. 15.2. Al-Qadi, I. L., J. F. Masson, A. Loulizi, P. Collins, J. R. Woods, S. Bundalo-Perc, and K. K. McGhee. Long-T
45、erm Accelerated Aging and Low Temperature BBR Testing of Sealants. Interim Report No. B5508-5. National Research Council of Canada, 2004, p. 262. 15.3. Al-Qadi, I. L., E. H. Fini, H. D. Figueroa, J. F. Masson, and K. K. McGhee. Adhesion Testing Procedure for Hot-Poured Crack Sealants, Final Report.
46、No. ICT-08-026. Illinois Center for Transportation, Rantoul, IL, December 2008. Available online at https:/www.ideals.illinois.edu/bitstream/handle/2142/45986/ICT-08-026.pdf?sequence=2. 1Formerly AASHTO Provisional Standard TP 89. First published as a full standard in 2017. 2017 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.
