days production of open-graded asphalt mix, by one of the following
methods: the extraction method in accordance with ASTM D 2172, Method A or
B, the ignition method in accordance with the ASTM D 6307, or the nuclear
method in accordance with ASTM D 4125, provided the nuclear gauge is
calibrated for the specific mix being used. For the extraction method, the
weight of ash, as described in ASTM D 2172, shall be determined as part of
the first extraction test performed at the beginning of plant production;
and as part of every tenth extraction test performed thereafter, for the
duration of plant production. The last weight of ash value obtained shall
be used in the calculation of the asphalt content for the mixture.
3.15.4
Gradation
Aggregate gradations shall be determined a minimum of twice per day from
mechanical analysis of recovered aggregate in accordance with ASTM D 5444.
When asphalt content is determined by the nuclear method, aggregate
gradation shall be determined from hot bin samples on batch plants, or from
the cold feed on drum mix plants. For batch plants, aggregates shall be
tested in accordance with ASTM C 136 using actual batch weights to
determine the combined aggregate gradation of the mixture.
3.15.5
Temperatures
Temperatures shall be checked at least four times per day, at necessary
locations, to determine the temperature at the dryer, the asphalt cement in
the storage tank, the asphalt mixture at the plant, and the asphalt mixture
at the job site.
3.15.6
Aggregate Moisture
The moisture content of aggregate used for production shall be determined a
minimum of once per day in accordance with ASTM C 566.
3.15.7
Moisture Content of Mixture
The moisture content of the mixture shall be determined at least once per
lot in accordance with ASTM D 1461 or an approved alternate procedure.
3.15.8
Air Voids
Voids total mix shall be determined from random core samples taken from
in-place open-graded asphalt mixture. Sample voids shall be calculated as
outlined in the Job Mix Formula criteria. Voids shall be between 25 and 35
percent. Material not meeting the void criteria shall be removed and
replaced at no additional cost to the Government.
3.15.9
Grade and Smoothness
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NOTE: Retain requirements for grade for projects
having large paved areas where standing water or
ponding of water may occur and projects with plan
and profile details. All other projects shall be
evaluated for the possibility of standing water
before removing the grade requirements.
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The Contractor shall conduct the necessary checks to ensure the grade and
smoothness requirements are met in accordance with paragraph ACCEPTABILITY
SECTION 02746
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