1、Standard Method of Test for Determining the Quality of Tack Coat Adhesion to the Surface of an Asphalt Pavement in the Field or Laboratory AASHTO Designation: TP 115-151American Association of State Highway and Transportation Officials 444 North Capitol Street N.W., Suite 249 Washington, D.C. 20001
2、TS-2c TP 115-1 AASHTO Standard Method of Test for Determining the Quality of Tack Coat Adhesion to the Surface of an Asphalt Pavement in the Field or Laboratory AASHTO Designation: TP 115-1511. SCOPE 1.1. This test method covers the determination of the tack coat adhesion quality as measured by the
3、tensile strength of tack coat materials on the free surface of asphalt pavement in the field or laboratory. 1.2. This test can be performed in the field on the surface of asphalt pavement or on 150-mm (6-in.) diameter, gyratory-compacted samples. 1.3. This standard may involve hazardous materials, o
4、perations, and equipment. This standard does not purport to address all safety concerns associated with its use. It is the responsibility of the user of this procedure to establish appropriate safety and health practices and to determine the applicability of regulatory limitations prior to use. 2. R
5、EFERENCED DOCUMENTS 2.1. AASHTO Standards: M 231, Weighing Devices Used in the Testing of Materials T 53, Softening Point of Bitumen (Ring-and-Ball Apparatus) 3. TERMINOLOGY 3.1. Definition: 3.1.1. tack coat adhesion qualitya measure of the ability of a tack coat material to bond to its underlying s
6、ubstrate as described by the adhesive tensile strength of the tack coat material. 4. SUMMARY OF METHOD 4.1. The standard test materials and test apparatus consist of the Louisiana Tack Coat Quality Tester (LTCQT), LTCQT software, computer, weights to hold the LTCQT in place during testing, and an in
7、frared reflective heating (IRH) device used to desiccate the emulsion and to adjust the tacked surface to the testing temperature. A thermometer should be used to determine the temperature. 4.2. The test procedure involves desiccating a tacked surface using the IRH device, adjusting the temperature
8、of the surface with the fan or heat gun to reach the testing temperature, and applying a compressive load to the tacked pavement surface for a given amount of time using the LTCQT device and software. At a prescribed displacement rate, the movement of the loading plate away 2015 by the American Asso
9、ciation of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-2c TP 115-2 AASHTO from the tacked surface results in tensile loading until failure. The maximum tensile strength reflects the quality of the adhesion of the tack coat material.
10、 5. SIGNIFICANCE AND USE 5.1. This test method is suitable for field or laboratory tests to determine the quality of tack coat adhesion as measured by the tensile strength. The knowledge of tack coat adhesion quality serves as a tool in characterizing the tack coat material. 5.2. The tensile strengt
11、h produced using this test method is influenced by the temperature at which the tacked surface is tested and the application rate of the tack coat material. 5.3. The tensile strength values measured by this test method, with the equipment and procedures stated herein, do not necessarily agree or cor
12、relate directly with other techniques of tack coat adhesion quality measurements. This test method is also suitable for research and development purposes, where direct comparisons between tack coat materials on a pavement surface are to be made within the same test program. 6. APPARATUS 6.1. Louisia
13、na Tack Coat Quality TesterThe device shall be equipped with a closed-loop servo motor actuator for precision control of the rate of displacement during testing. It shall be capable of measuring loads of up to 446 N (100 lbf) with an accuracy of 1 percent. The displacement of the actuator shall be m
14、easured using a position transducer that has a total travel of 100 mm (4 in.). The diameter of the loading plate shall be 100 mm (4 in.). The device is illustrated in Figure 1. Note: The tolerance for all dimensions is 0.005 in. Figure 1Illustration of the LTCQT Device 6.5 in.ActuatorMounting PlateP
15、ress PlateRamLoad CellWeightPlatform21.0 in.16.9in.Depth 12.0 in.(profile view not shown) 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-2c TP 115-3 AASHTO 6.2. Computer and SoftwareThe software shal
16、l be designed such that it displays the time, normal load, and displacement of the actuator continuously during testing while graphically illustrating the relationship of the normal load and time. It shall allow the user to input the required compressive load, the time to hold the compressive load,
17、and the displacement rate required. The actual holding time of the compressive load shall be displayed during testing as well as the actual displacement rate. In addition, the software shall allow the user to move the actuator manually. 6.3. Infrared Reflective Heating SourceIt shall be equipped wit
18、h a 250-watt, 120-volt bulb. It shall be designed such that it can be positioned 150 mm (6 in.) from the surface to be tested without making contact with the tacked surface. 6.4. ThermometerThe thermometer shall be suitable to measure the temperature of a tacked surface without directly contacting t
19、he test area. It is recommended that an infrared thermometer be utilized. 6.5. WeightsThe weights used shall be equal to or greater than the expected maximum normal load. Note that the normal load applied by the machine cannot exceed 446 N (100 lbf). 6.6. Temperature Control DevicesThe devices shall
20、 adjust the surface temperature to the required test temperature. It is recommended that a fan be used to cool the tacked surface and a heat gun be used to heat the tacked surface. 6.7. Weighing DeviceThe weighing device shall have sufficient capacity, be readable to 0.1 percent of the sample mass o
21、r better, and conform to the requirements of M 231. 7. HAZARDS 7.1. Standard laboratory safety precautions must be observed when preparing and testing asphalt mixture specimens. 8. TEST SPECIMENS 8.1. Testing areas shall be cleaned prior to the tack coat application. 8.2. Tack coat material shall be
22、 applied using the appropriate method. For laboratory specimens, apply the tack coat material at the specified application rate using a 1-in. natural bristle brush. Utilize a laboratory scale to ensure that the correct amount of tack coat is applied. Field sections typically use a distributor truck
23、for spray application of tack coat material. 8.3. For field testing, a 150 mm (6 in.) by 150 mm (6 in.) area of tacked surface shall be desiccated prior to testing. It is recommended that this be accomplished by placing the IRH source 150 mm (6 in.) above the tacked surface for a minimum of 1 h. Not
24、e that this time may be extended for bulk application rates greater than 0.05 gal/yd2. 8.4. Number of Test AreasA single test shall consist of at least three test areas. Laboratory testing requires three samples prepared using a Superpave Gyratory Compactor (SGC). 8.5. The test areas shall be number
25、ed and the locations shall be documented. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-2c TP 115-4 AASHTO 9. PROCEDURE 9.1. Testing areas (specimen) shall be conditioned to the correct testing temp
26、erature using the IRH device. It is recommended that the softening point (established according to T 53) of the tack coat material be used as the testing temperature. 9.2. Device PositioningPlace the LTCQT directly above the tacked surface to be tested. Lift up the front end of the device to verify
27、that the loading plate is positioned directly above the tacked surface that will be tested. 9.3. A typical weight of 180 N (40 lbf) shall be placed on top of the LTCQT device. 9.4. The compressive load (89 N (20 lbf), time to hold the compressive load (3 min), and the displacement rate (0.2 mm/sec (
28、0.008 in./sec) shall be entered into the computer by the user. 9.5. Zero the load reading prior to the initiation of the test. It is also recommended that the plate be positioned as close as possible to the tacked surface prior to testing so as to minimize the change in temperature. 9.6. The compres
29、sive load shall be mechanically applied to the tacked surface for the specified amount of time (3 min). Once the allotted time has ended, the loading plate shall automatically be raised away from the tacked surface at the prescribed displacement rate. The software shall by design record the normal l
30、oad, vertical displacement, and time throughout the test. Record the ultimate tensile load (Pult) of the tack coat material. A graph of a typical test result is shown in Figure 2. Figure 2Typical Test Results 10. CALCULATIONS 10.1. Calculate the tack coat adhesion quality, TCQ, as follows: 24ultPTCQ
31、D=s(1) TensileLoad(lbf)00 2 4 6 8 10Time (s)Pult12510152025304035 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-2c TP 115-5 AASHTO where: TCQ = tack coat adhesion quality, Pa (psi) Pult= ultimate te
32、nsile load, N (lbf) D = diameter of the loading plate, m (in.) 11. REPORT 11.1. The report must include the following parameters: 11.1.1. Test location. 11.1.2. Note the appearance of the tacked surface before and after testing including any contaminants, milling striations, stripping, tack coat str
33、eaks, etc. 11.1.3. Softening point temperature, C (F). 11.1.4. Loading Plate DimensionsIncluding the diameter and the cross-section area. 11.1.5. Test Results: 11.1.5.1. Ultimate tensile load, nearest 4.4 N (1 lbf). 11.1.5.2. Tensile strength, nearest 68.9 Pa (0.01 psi). 11.1.5.3. Corresponding vert
34、ical deformation, nearest 0.025 mm (0.001 in.). 11.1.5.4. Average and standard deviation of tensile strength for the set of tested areas. 12. PRECISION AND BIAS 12.1. The precision and bias statements for this method have not been determined. 13. KEYWORDS 13.1. Asphalt overlay; slippage failure; tack coat; tack coat adhesion quality; tensile strength. 1This provisional standard was first published in 2015. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.
