the retained coating area is less than 95 percent, the aggregate stripping
tendencies shall be countered by the use of hydrated lime or by treating
the bitumen with an approved antistripping agent as furnished by the
Contractor. The hydrated lime will be considered as mineral filler and
lime or antistripping agent added to the bitumen will be determined during
development of the JMF and will be sufficient to produce a retained coating
area greater than 95 percent. Use of additional antistripping agent may be
directed during progress of the work, if necessary. No additional payment
will be made to the Contractor for addition of antistripping agent required.
PART 3
EXECUTION
3.1
PREPARATION
3.1.1
Weather Limitations
The PFC course shall be constructed only when the existing pavement is dry.
Unless otherwise directed, the PFC shall not be constructed when the
temperature of the existing pavement surface is below 15 degrees C 60
degrees F.
3.1.2
Surface Preparation
**************************************************************************
NOTE: Appropriate statements covering the required
conditioning of existing pavement will be inserted.
Deficiencies in surface smoothness must be remedied
by repairing or patching localized areas or by
**************************************************************************
Prior to placing of PFC, the underlying course shall be cleaned of any
foreign or objectionable matter by thorough power brooming. Any underlying
course showing evidence of oil or grease shall be removed and replaced.
3.1.3
Preparation of Bituminous Mixtures
Rates of feed of aggregates shall be regulated so that moisture content and
temperature of aggregates will be within tolerances specified. Aggregates
and bitumen shall be conveyed into the mixer in proportionate quantities
required to meet the JMF. Mixing time shall be as required to obtain a
uniform coating of the aggregate with the bituminous material. Temperature
of bitumen at time of mixing shall not exceed 150 degrees C 300 degrees F.
Temperature of aggregate in the mixer shall not exceed 165 degrees C 325
degrees F when bitumen is added. Overheated and carbonized mixtures or
mixtures that foam shall be discarded.
3.1.3.1
Water Content of Aggregates
Drying operations
shall reduce the water content of the aggregate mixture
to less than 0.75
percent. Water content will be determined in accordance
with ASTM D 2216;
weight of sample shall be at least 500 grams 500 grams.
The water content
shall be reported as a percentage of the total aggregate
mixture.
3.1.3.2
Storage of PFC
The PFC paving mixture shall not be stored for longer than 15 minutes prior
SECTION 02747
Page 16