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measure fundamental material properties _at govern pavement performance, the SUPERPAVE ® system is applicable<br />
to either standard asphalt-aggregate paving mixzs or modified asphalt-aggregate paving mixes.<br />
10.4.1 Specimen Preparation--Prepare all required cylindrical specimens of modified<br />
mix using the <strong>SHRP</strong> gyratory compactor in conformance with <strong>SHRP</strong> M-002. Blend or<br />
combine modifiers with the base asphalt cement, aggregate, or paving mix, as appropriate, in<br />
accordance with the producer's instructions.<br />
NOTE 15.--When required, prismatic beam specimens may be prepared in conformance with <strong>SHRP</strong> M-008<br />
(rclling wheel compaction) or other appropriate means.<br />
10.4.2 Conditioning and' Testing--Condition and test the modified mix in accordance<br />
with the SUPERPAVE ®Mix Design Manual for New Construction and Overlays and relevant<br />
procedures and methods referenced therein. Table 6 presents a summary of the conditioning<br />
procedures and performance-based test methods generally employed.<br />
10.4.3 Evaluation--Accomplish evaluation by estimating the performance of a<br />
pavement constructed with the modified paving mix. Make calculations using the pavement<br />
performance prediction algorithms in the SUPERPAVE ® software. This permits an objective<br />
comparison of the performance characteristics of the modified paving mix to the standard or<br />
conventional paving mix.<br />
10.4.3.1 Conduct laboratory aging of the modified paving mix principally to<br />
condition the specimens used in the performance-based mix tests in table 6. This conditioning<br />
simulates the short- and long-term aging that occurs during HMA production and pavement<br />
service. In addition, if the dynamic modulus of aged specimens is measured and compared<br />
with that of unaged specimens, the rate and degree to which the modified paving mix will<br />
age, compared to a conventional asphalt paving mix, can be estimated.<br />
10.4.3.2 Conduct moisture conditioning in the laboratory to identify candidate paving<br />
mixes that have an unacceptable moisture susceptibility. These mixes can then be eliminated<br />
or subjected to remedial treatment. Changes in tensile strength or dynamic modulus provide a<br />
direct measure of moisture susceptibility. Optionally, test the conditioned specimens in any of<br />
the performance-based mix tests to determine the effect of moisture on the development of<br />
specific pavement distresses.<br />
10.4.3.3 The contribution of the paving mix to permanent deformation is gauged by<br />
the results of <strong>SHRP</strong> M-003. _s simulates the high shear stresses that develop near the<br />
pavement surface at the edges of tires, and that lead to both lateral and vertical deformations.<br />
Estimate the rut depth after any selected number of ESALs (equivalent single axle loads of<br />
80 kN) from the number of shear repetitions (in the repetitive shear, constant height test)<br />
needed to reach an accumulated permanent strain of 5 %. Conduct this test at a test<br />
temperature related to the maximum expected pavement temperature. Evaluate the potential<br />
for catastrophic, tertiary creep in the pavement with the repetitive shear test at a field state of<br />
stress. Conduct this test for 4000 cycles at an effective temperature and stress state<br />
appropriate for the paving project. Finally, use the results of the uniaxial strain, simple<br />
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