Table 4.
Minimum Percent Voids in Mineral Aggregate (VMA)(4)
Aggregate (See Table 2)
Minimum VMA, percent
Gradation 1
13.0
Gradation 2
14.0
15.0
(4) Calculate VMA in accordance with AI MS-02, based on ASTM D 2726
bulk specific gravity for the aggregate.
2.3.2
Adjustments to JMF
The JMF for each mixture shall be in effect until a new formula is approved
in writing by the Contracting OfficerEngineer. Should a change in sources
of any materials be made, a new mix design shall be performed and a new JMF
approved before the new material is used. The Contractor will be allowed
to adjust the JMF within the limits specified below to optimize mix
volumetric properties. Adjustments to the JMF shall be limited to plus or
minus 4 percent on the 4.75 mm No. 4 and coarser sieves; plus or minus 3
percent on the 2.36 mm No. 8 to 0.30 mm No. 50 sieves; and plus or minus 1
percent on the 0.15 mm No. 100 sieve. Tolerances given above may permit
the aggregate grading to be outside the limits shown in Table 2; this is
acceptable. Adjustments to the JMF shall be limited to plus or minus 1.0
percent on the 0.075 mm No. 200 sieve. The resulting aggregate grading on
the 0.075 mm No. 200 sieve shall not be outside the limits shown in Table
2. Asphalt content adjustments shall be limited to plus or minus 0.40 of
binder content. If adjustments are needed that exceed these limits, a new
mix design shall be developed.
2.4
RECYCLED HOT MIX ASPHALT
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NOTE: Reclaimed Asphalt Pavement (RAP) should not
be used for surface mixes, except on shoulders. It
can be used very effectively in lower layers, or for
shoulders. The Contractor should be able to use
RAP, up to 30%, as long as the resulting recycled
mix meets all requirements that are specified for
virgin mixtures. Remove these paragraphs if RAP is
not used.
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Recycled HMA shall consist of reclaimed asphalt pavement (RAP), coarse
aggregate, fine aggregate, mineral filler, and asphalt cement. The RAP
shall be of a consistent gradation and asphalt content and properties.
When RAP is fed into the plant, the maximum RAP chunk size shall not exceed
50 mm 2 inches. The recycled HMA mix shall be designed using procedures
contained in AI MS-02. The job mix shall meet the requirements of
paragraph MIX DESIGN. RAP should only be used for shoulder surface course
mixes and for any intermediate courses. The amount of RAP shall be limited
to 30 percent.
2.4.1
RAP Aggregates and Asphalt Cement
The blend of aggregates used in the recycled mix shall meet the
requirements of paragraph AGGREGATES. The percentage of asphalt in the RAP
SECTION 02749
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