SHRP-A-379 traducir

10.4.3.8 If the estimated performance of the modified paving mix or its cost-benefit
ratio are unacceptable, then the evaluation of this modifier can be abandoned or the
evaluation repeated to optimize the selection of materials or the mix design.
NOTE 17.--The specifying agency may choose to further optimize the modified paving mix even though the
results are favorable. It may also choose to proceed to pavement construction regardless of the results of the
mo:iified mix evaluation in order to develop additional data for a final decision on the use of the candidate modifier.
11. THE SUPERPAVE ® MIX DESIGN SYSTEM
11.1 The performance-based testing described in sections 8 and 10 may all be
conducted, if desired, within the context of the SUPERPAVE ®mix design system. This
system is founded on measurement of fundamental material properties of the asphalt binder
and paving mix, and is fully applicable to unmodified and modified systems. It should be
routinely employed to produce optimized mix designs incorporating those modifiers shown
effective for enhancing pavement performance through the procedures in sections 8 and 10.
11.2 The SUPERPAVE ® mix design system develops an initial mix design based on
volumetric mix properties. TIEs design is then optimized on the basis of pavement
performance estimates calculated from fundamental material properties of the trial paving
mix.
11.3 Only the volumetric design is required for low traffic levels. At intermediate
traffic levels (typically 10 6 tO 107 total design ESALs), the volumetric design and a
streamlined series of performance-based paving mix tests selected from those in table 6 are
conducted. For high traffic levels, the volumetric design and the full set of accelerated
performance tests summarized in table 6 are advised. The SUPERPAVE ® system provides
unique specification guidelines and criteria for each level of mix design.
11.4 For modifiers with established performance capabilities, the mix design system
can be used alone to develop modified paving mixes with optimal performance
characteristics. The comparative testing of conventional asphalt binders or paving mixes is
not necessary.
12. MODIFIED ASPHALT PAVEMENT EVALUATION
12.1 Table 7 presents key information that should be developed to guide the
production, construction, and evaluation of modified asphalt pavements. Information should
be supplied by the modifier producer concerning the equipment and procedures necessary for
the field production and construction of the modified asphalt pavements. Any atypical HMA
operations should be carefully reviewed jointly with the HMA contractor and the modifier
producer. This will help identify any potential operational problems or special equipment
needs. This information must include health and safety data, conditions for handling and
storage of the modified asphalt binder and paving mix, and special field control requirements
tc ensure that the plant mix will provide the expected performance.
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