control limits is 3.0 percent.
d. Air Content Corrective Action - Whenever points on the control
chart approach the upper or lower control limits, an adjustment should
be made in the amount of air-entraining admixture batched. If a single
test result is outside the specification limit, immediate adjustment is
mandatory. As soon as practical after each adjustment, another test
shall be made to verify the correction of the adjustment. Whenever a
point falls above the upper control for range, the dispenser shall be
calibrated to ensure that it is operating correctly and with good
reproducibility. Whenever two consecutive points either for average or
range are outside the control limits, the Contracting Officer shall be
notified.
3.10.2.7
Field Density
a. Testing and Checking - Density shall be determined for [each 450
square meters 5,000 square feet of completed lift] [at least eight
locations per RCC lift] with a calibrated nuclear density gauge in
accordance with ASTM C 1040. Densities shall be taken at depths of 100
and 200 mm 4 and 8 inches. If the densities at 100 and 200 mm 4 and 8
inches conflict, acceptance shall be at the 200 mm 8 inch depth.
b. Action Required - Whenever the nuclear gauge indicates density less
than the specified density, a retest shall be made. If the retest
indicates unacceptable density, the Contracting Officer's
Representative shall be notified, additional rolling shall be
immediately provided, and a determination shall be made as to whether
the lower density resulted from insufficient passes of the roller or a
change in the mix properties. If the mix properties have changed,
adjustments such as increasing or decreasing the moisture content shall
be made at the batch plant. If the problem persists, the Contracting
Officer may adjust the proportions of aggregates, cement, and/or
pozzolan. If the lower density is the result of incomplete rolling,
the operator shall be notified and the Contracting Officer may require
removal of the incompletely compacted material at no cost to the
Government.
3.10.2.8
Inspection Before Placing
Foundation or construction joints, forms, and embedded items shall be
inspected by the Contractor in sufficient time prior to each concrete
placement to certify to the Contracting Officer that they are ready to
receive concrete. The results of each inspection shall be reported in
writing. The inspection of the lift surfaces of the RCC will be a
continuing activity and shall be accomplished in accordance with paragraph
REGULAR LIFT-JOINT TREATMENT.
3.10.2.9
Placing Inspection
a. Inspection - The Contractor shall provide full time supervision of
all placing operations to insure that the correct quality of RCC,
conventional concrete, or grout is placed in each location and that all
other aspects of the placing operation are performed in accordance with
the contract. During placing operations, the quality control staff
shall measure and record concrete temperatures in accordance with ASTM
C 1064/C 1064M, ambient temperature hourly, record weather conditions,
time of placement, yardage placed, and method of placement.
SECTION 03701
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