AASHTO TP 91-15 pdf free download

AASHTO TP 91-15 pdf free download.Determining Asphalt Binder Bond Strength by Means of the Binder Bond Strength (BBS) Test.
9. AGGREGATE TEST SPECIMENS
9.1. SoliclAggregate Substrates—Cut aggregate substrates from either quarried rocks or cored rock samples using standard rock saws such that the plate faces arc parallel. Lap all substrates using a 280-grit silicon carbide material on a standard lapidary wheel to remove saw marks and ensure a consistent surface roughness. Once cut and lapped, clean the samples for 60 mm in an ultrasonic cleaner containing distilled water at a temperature of 60 ± 1°C (140 2°F) to remove residual particles on the plate surface. Limit the use of the same solid aggregate substrate to five times per cut surface.
9.2. composite Substrates—Composite substrates contain aggregate chips and a rapid-setting cement compound. Prepare composite substrates by casting samples in portland cement concrete cylinder molds measuring 15.2cm (6 in.) in diameter and 35.4cm (13.9 in.) in height. Cure samples according to the cement compound manufacturer’s instructions. After curing, cut, lap, and clean the composite substrates according to the procedures provided in Section 9.1 for aggregate substrates. Limit the use of the same composite substrate to five times per cut surface.
9.3. Substrate Di,nensions—Cut solid aggregate or aggregate composite substrates to a minimum thickness of 20 mm (0.8 in.) and dimensions that provide sufficient surface area for placement of four pull-off stubs on one substrate. A minimum center-to-center spacing between the two pull-off stub shafts of 73.0 mm (2.87 in.) is required for clearance of the load assembly.
Note 3—Asphalt MLuure Substrates. Asphalt mixture core samples obtained from ficld sites arc not used as a substrate due to deviations in surface roughness, which does not allow for uniform binder film thickness. For laboratory asphalt mixture specimens prepared using a Superpave gyratory compactor, lapping surfaces will damage the lapidary equipment and is not recommended.
10. SAMPLE PREPARATION
10.1. Hot-Applied Binders and Emulsion Residues:
10.1.1. Obtain a representative sample of the material for testing using the procedures specified in R 66. Handle materials and instruments with clean laboratory gloves throughout the test procedure to prevent contamination of the testing surfaces.
10.1 .2. Place the substrates and the pull-off stubs in a forced-draft oven at 150 + 2°C (302 ± 4°F) for a minimum of 30 mm to remove any residual moisture from the substrate surface and to preheat the pull-off stubs for application. For emulsion residues place the substrates and pull-off stubs in a forced-draft oven at 80 ±2°C (176 ± 4°F).
10.1.3. Remove the substrates from the first forced-draft oven, and place them in a second forced-draft oven at the user-defined application temperatures for a minimum of 1 h.
Note 4——Bond strength measurements are significantly influenced by application temperature. It is recommended that the user select an application temperature similar to those for HMA (hot mix asphalt) or WMA (warm mix asphalt) mixture production. For emulsion residues a minimum pull- off stub application temperature of 80°C (176°F) is recommended to ensure adhesion between the stub and residue.
10.1.4. While the substrates reach the application temperature, heat the hot-applied asphalt binder in an appropriate container to the asphalt binder melting temperature in a forced-draft oven. Minimize or preferably avoid heating of emulsion residues.AASHTO TP 91-15 pdf download.