1、Standard Method of Test for Determining Asphalt Binder Bond Strength by Means of the Binder Bond Strength (BBS) Test AASHTO Designation: T 361-161Release: Group 3 (August 2016) American Association of State Highway and Transportation Officials 444 North Capitol Street N.W., Suite 249 Washington, D.C
2、. 20001 TS-2a T 361-1 AASHTO Standard Method of Test for Determining Asphalt Binder Bond Strength by Means of the Binder Bond Strength (BBS) Test AASHTO Designation: T 361-161Release: Group 3 (August 2016) 1. SCOPE 1.1. This test method quantifies the tensile force needed to remove a pull-off stub a
3、dhered to a solid substrate with asphalt binder. Samples are prepared at controlled environmental and moisture conditions (i.e., temperature and humidity). After conditioning, a pneumatic load is applied to a pull-off stub using an ASTM D4541 Type IV adhesion tester until failure. The pull-off tensi
4、le strength and mode of failure are used to describe the bonding properties of the asphalt binder and compatibility between aggregates and asphalt binders. 1.2. The values stated in SI units are to be regarded as the standard. 1.3. This test may involve hazardous materials, operations, and equipment
5、. This standard 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 health practices and determine the applicability of regulatory limitations prior to use. 2. REFERENCED DOCUMENTS 2.1. AASHTO Standa
6、rds: M 140, Emulsified Asphalt M 208, Cationic Emulsified Asphalt M 316, Polymer-Modified Emulsified Asphalt R 66, Sampling Asphalt Materials T 315, Determining the Rheological Properties of Asphalt Binder Using a Dynamic Shear Rheometer (DSR) 2.2. ASTM Standards: D4541, Standard Test Method for Pul
7、l-Off Strength of Coatings Using Portable Adhesion Testers D4753, Standard Guide for Evaluating, Selecting, and Specifying Balances and Standard Masses for Use in Soil, Rock, and Construction Materials Testing E77, Standard Test Method for Inspection and Verification of Thermometers E145, Standard S
8、pecification for Gravity-Convection and Forced-Ventilation Ovens 2016 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-2a T 361-2 AASHTO 3. TERMINOLOGY 3.1. Definitions: 3.1.1. failure modeindicator of the
9、weakest component of the asphalt/surface syst em. In applications to this test procedure failure can occur at three locations: within the asphalt binder, at the asphalt binder/substrate interface, or in a mixed mode. 3.1.2. pull-off tensile strengththe pressure required to remove a pull-off stub att
10、ached to a prefabricated surface by asphalt binder, with force applied in the normal direction. Used in this procedure as a parameter to evaluate the quality of the bond. 3.1.3. saturated surface-dry (SSD) conditionin this condition, the void structure of the aggregate is filled with moisture, while
11、 the main surface area of the aggregate particles remains dry. 4. SUMMARY OF METHOD 4.1. The adhesion tester applies a pneumatic load via a pressure ring to a pull-off stub fixed to a rigid substrate with asphalt binder, as shown in Figure 1. The binder is adhered to the substrate and subjected to d
12、ifferent curing conditions. For curing emulsified binders, fixed levels of temperature and humidity are used. Moisture conditioning is used for both hot-applied binders and emulsified asphalt residues to evaluate the effects of moisture damage. Pressure and time are monitored during the test and the
13、 load is applied until failure. The output of the test is pressure at failure. The surface is also inspected visually to determine the nature of failure. Figure 1Schematic Representation of the Testing Assembly for the Binde r Bond Strength Test 5. SIGNIFICANCE AND USE 5.1. Pull-off tensile strength
14、 values measured over a range of environmental conditions and curing times provide information related to the bond strength at the interface between a substrate and hot-applied or emulsified asphalt binders. 5.2. Evaluation of pull-off tensile strength on different aggregate substrates provides a me
15、asure of asphalt-aggregate compatibility. 5.2.1. Applications to emulsified binders include assessment of curing rate and ultimate tensile strength. Pull-off Stub Pressure Ring Reaction Plate Pull-off Stub Asphalt Binder Metal Ring Support Substrate Air Pressure Gasket 2016 by the American Associati
16、on of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-2a T 361-3 AASHTO 5.2.2. Applications to hot-applied asphalt binders and recovered emulsified asphalt residues include evaluation of the effects of application temperature and moistu
17、re conditioning on pull-off tensile strength. 6. APPARATUS 6.1. Molds: 6.1.1. Emulsified Asphalt BindersFor emulsified asphalt binder s, use a silicone mold measuring approximately 20 mm (0.79 in.) in diameter, 5 mm (0.20 in.) in width, and 5 mm (0.20 in.) in thickness. The mold has no backing and i
18、s used to contain the emulsified asphalt on the aggregate surface. A diagram of the mold is shown in Figure 2a. 6.1.2. Hot-Applied Asphalt Binders and Emulsified Asphalt Residues Use a silicone mold measuring approximately 40 mm by 40 mm (1.6 in. by 1.6 in.) with an 8-mm (0.32-in.) diameter cavity a
19、nd a 2.0-mm (0.08-in.) depth. This mold is similar to the molds used to prepare Dynamic Shear Rheometer (DSR) test samples in T 315. A diagram of the mold is shown in Figure 2b. 40408(a) (b) Figure 2Mold Dimensions (mm) for Emulsified Binders (a) and Hot Binder s (b) Drawings Not to Scale 6.2. Subst
20、rateComposed of solid aggregate or aggregate composite with dimens ions as defined in Section 9. 6.3. Testing MachineUse a Type IV adhesion tester as defined by ASTM D4541 for all tests. At a minimum the device must consist of the components detailed in Sections 6.3.1 through 6.3.3. An example of a
21、testing machine is shown in Figure 3. Note 1The testing apparatus shown in F igure 3 is a commercially available device produced by GARDCO, Inc. The F-4 piston depicted in the figure has a diameter of 73.0 mm (2.88 in.). Other devices meeting the requirements of this procedure can be used. 6.3.1. Co
22、ntrol ModuleCapable of controlling the air pr essure load range from 7 to 35,000 kPa (1 to 5000 psi), and equipped with a digital or analog display, loading rate control, and data acquisition software capable of monitoring air pressure over time. 6.3.2. Load AssemblyConsists of a piston, reaction pl
23、ate, gasket and air hose. 5 mm20 mm 2016 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-2a T 361-4 AASHTO 6.3.2.1. Piston and Reaction PlateSelect a piston and reaction plate assembly with sufficient diam
24、eter to allow for loading of the sample until failure. Air pressure at failure is a function of test temperature, loading rate, and asphalt binder stiffness. Application of the device to asphalt binders and mastics indicates that a minimum piston/reaction plate diameter of 57.2 mm (2.25 in.) is requ
25、ired. 6.3.2.2. GasketComposed of polymer or other material with properties and dimensions capable of providing an air-tight seal between the piston and reaction plate. The gasket must be inspected regularly to ensure the air-tight seal is maintained and replaced when the gasket is no longer function
26、ing. 6.3.2.3. Air HoseRated for a maximum kPa (psi) value that exceeds the air supply specified in Section 6.3.3. Figure 3General Representation of Binder Bond Strength Test Apparatus 6.3.3. Air SupplyCapable of producing a consistent air pressure of at least 0.7 MPa (100 psi) as read on the supply
27、gauge. Self-contained air cylinders, shop (bottled) air, or air from an automatic pump can be used. 6.4. Pull-off StubsStainless steel or any other suitable material, with dimensions as shown in Figure 4. Stub edges are beveled to reduce the amount of binder trapped between the stub edge and substra
28、te and to ensure a uniform film thickness. Inspect the pull-off stub edges frequently to verify that the edge is consistent along the diameter of the stub with no visible chips or dents. Discard damaged stubs. The stub surface is roughened to increase the surface area in contact with the asphalt bin
29、der. Note 2The dimensions presented in Figure 4 are specific to the device used in the development of this test procedure. If another device is used adjust the dimensions to match the pull-off stub with the load assembly of the device. Pull-off stub diameter (20 mm (0.8 in.) in Figure 4) is an 2016
30、by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-2a T 361-5 AASHTO input to the calculation of pull-off tensile strength (POTS). Maintain a tolerance of 0.025 mm (0.001 in.) in stub diameter to ensure consi
31、stent results. The procedure was developed based on a pull-off stub diameter of 20 mm; it is recommended the user maintain this dimension for testing. Roughened Stub Surface Profile View (mm) Bottom View (mm) Dimensional Equivalents mm 0.8 5 6 7 15 20 22 40 in. 0.03 0.2 0.24 0.28 0.6 0.8 0.9 1.6 Fig
32、ure 4Pull-off Stub Dimensions for Binder Bond Strength Test 6.5. Ring SupportProvides support to the piston and reaction plate support; als o provides space between the substrate and load assembly to minimize the risk of eccentric loading. The ring support (e.g., a shaft collar) has minimum dimensio
33、ns of 12.5 mm (0.5 in.) in height and a 25.4-mm (1.0-in.) inside diameter. An example of a ring support is shown in Figure 5. Figure 5Pull-off Stub Metal Ring support 6.6. Forced-Draft OvenCapable of maintaining temperat ures of at least 150 3C (302 6F) for preparing all aggregate and binder samples
34、. Use as many temperature-controlled ovens of Type IIA or IIB as defined in ASTM E145 as necessary to accommodate different heating conditions required in the sample preparation process detailed in Section 10. 6.7. Environmental ChamberCapable of maintaining temperat ures between 15 and 75 1C (60 an
35、d 167 2F) and a relative humidity between 20 and 80 percent 1 percent, for curing all emulsified asphalt samples. 654020722150.82220 2016 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-2a T 361-6 AASHTO 6
36、.8. ThermometerFor tests performed at 25C (77F), use an ASTM Thermometer No. 17C (17F) to measure the temperature of the substrate surface prior to testing. For tests performed at other temperatures, use ASTM thermometers of an appropriate range and accuracy equal to that of the No. 17 thermometer.
37、Since the accuracy of the test results is dependent upon closely controlled temperature conditions, calibrate thermometers in accordance with ASTM E77. Thermometric devices with the same accuracy as ASTM thermometers may also be used. 6.9. ContainerAny suitable container may be used to hold the hot-
38、applied asphalt binder or emulsified asphalt residue material while it is being melted. For emulsified asphalt binders, the container may be plastic, nonmetal, or, if metal, epoxy-lined. 6.10. Ultrasonic CleanerNeeded to remove residual particles from substrate surfaces prior to testing. Capable of
39、maintaining bath temperatures of 60 1C (140 2F) and with a sufficiently large chamber to allow for complete submersion of the substrate. 6.11. 280-Grit Silicon Carbide MaterialOn a standard lapidary wheel to ensure uniform roughness on the substrate. 6.12. Bench ScaleCapable of meeting G2 requiremen
40、ts as specified in M 231. 6.13. Water Bath Capable of maintaining a minimum temperature of 40 3C (104 6F) and with sufficient dimensions to allow for complete submersion of asphalt-aggregate systems in water during moisture conditioning. 7. SAFETY PRECAUTIONS 7.1. Observe standard laboratory safety
41、precautions when preparing and testing hot-applied asphalt binders and emulsified asphalts. 8. CALIBRATION OF TESTING EQUIPMENT 8.1. Verify the operating condition of all physical components in the testing system (i.e., air supply, pressure ring, software, and connections) prior to testing. 8.2. Cal
42、ibration of Loading Rate: 8.2.1. Turn on the adhesion testing equipment, computer, and data acquisition system per the manufacturers instructions. 8.2.2. Insert the gasket into the piston and place the reaction plate over the piston, as indicated in Figure 3. Clamp the top (reaction plate) and botto
43、m (piston) of the loading assembly using an appropriately sized C-clamp. 8.2.3. Set the loading rate to the predetermined setting, noting the position of the loading rate setting relative to the position that corresponds to the minimum or zero loading rate. 8.2.4. Apply air pressure for a maximum of
44、 3 s. Monitor the air pressure versus time through the data acquisition system or manual readings. For electronic sampling devices, this step also verifies that the data acquisition system is functioning. 8.2.5. Calculate the loading rate based on the slope of the “air pressure versus time” curve be
45、tween 20 and 80 percent of the maximum pressure. Verify that the actual loading rate is within 10 percent of 2016 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-2a T 361-7 AASHTO the pre-selected target v
46、alue. If the measured value falls outside the target range, adjust the pressure setting, and repeat Sections 8.2.2 through 8.2.4. 8.3. Conduct the verification of testing equipment and calibration of loading rate procedures specified in Sections 8.1 and 8.2 prior to each day of bond strength testing
47、. 9. AGGREGATE TEST SPECIMENS 9.1. Solid Aggregate SubstratesCut aggregate substrates from either quarried rocks or cored rock samples using standard rock saws such that the plate faces are parallel. Lap all substrates using a 280-grit silicon carbide material on a standard lapidary wheel to remove
48、saw marks and ensure a consistent surface roughness. Once cut and lapped, clean the samples for 60 min in an ultrasonic cleaner containing distilled water at a temperature of 60 1C (140 2F) to remove residual particles on the plate surface. Limit the use of the same solid aggregate substrate to five
49、 times per cut surface. Note 3When large aggregate samples are not available, composite substrates can be made from aggregate chips and a rapid-setting cement compound. Prepare composite substrates by casting samples in molds with dimensions that meet or exceed requirements. Cure samples according to the cement compound manufacturers instructions. After curing, cut, lap, and clean the composite substrates according to the procedures provided in Sections 9.1 and 9.2. Inspect the surface of the cut
