SHRP-A-379 traducir

46-x or PG 52-x, 100°C for binders having high-temperature grading designations of PG
58-x and higher. A PAV temperature of 110°C is used in simulating desert environments.
NOTE 8.--Two BBR beams requiring PAV material are required. In addition, four DT samples may also
be needed requiring about 60 g of PAV-conditioned asphalt binder.
7.10 Complete steps 7.1 through 7.9 during the first day of testing. This will allow
further testing to begin on the second day, when the PAV procedure is complete.
7.11 At the conclusion of the PAV procedure, carefully remove the residue from the
vessel and combine individual pans of the same aged asphalt binder. Prepare two bending
beam specimens according to TP1. Retain sufficient residue to prepare four direct tension
specimens if required.
7.12 Perform the DSR test (TP5) on the PAV residue at the test temperature
specified in table 1 of MP1 indicated for the high-temperature and low-temperature grading
designation of the binder being verified. For example, test a PG 64-40 asphalt binder at
16°C. The value for G'sin 6 must not exceed 5000 kPa to meet the requirements of MP1
(note 7).
7.13 Test two BBR specimens according to TP1 at the test temperature specified in
table 1 of MP1 indicated for the high temperature and low temperature grading designation
of the binder being verified. For example, test a PG 58-28 asphalt binder at -18°C. The
value of the slope in must be > 0.300 to meet the requirements of MP1. Certain asphalt
binders may satisfy the BBR slope requirement at substantially lower temperatures than
they satisfy the BBR stiffness requirement (note 7).
7.14 Determine the extent of physical hardening, report the creep stiffness (S) and
the slope (rn) of the log creep stiffness versus log time relationship measured at I hour
(conducted above in section 7.13) and 24 hours. Prepare two BBR specimens of original
asphalt binder. Condition and test the specimens at the test temperature, selected from table
1 of MP1, appropriate for the performance grade of the asphalt binder. For example, if the
binder grade being verified is a PG 64-34 asphalt binder, condition and test the BBR
specimens at -24°C. Test one set after 1 hour of conditioning and the second set after 24
hours of conditioning.
7.15 If the creep stiffness is between 300.0 and 600.0 MPa and the slope m is _>
0.300 at the test temperature, it may be possible to satisfy the DT failure strain requirement
in lieu of the creep stiffness requirement. Test four DT samples according to TP3 at the
same test temperature used to test the BBR specimens. The failure strain must be >_1.0% to
meet the requirements of MPI (note 7).
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