selected by the Contractor as the most advantageous for control.
However, the Contractor is responsible for delivering fine aggregate to
the mixer within specification limits.
b. Corrective Action for Fine-Aggregate Grading - When the amount
passing on any sieve is outside the specification limits, the fine
aggregate shall be immediately resampled and retested. If there is
another failure on any sieve, the fact shall immediately be reported to
the Contracting Officer.
c. Moisture Content Testing - There shall be at least four tests for
moisture content in accordance with ASTM C 566 during each 8-hour
period of mixing plant operation. The times for the tests shall be
selected randomly within the 8-hour period. An additional test shall
be made whenever the grout flow is out of control or excessive
variation in consistency is reported by the placing foreman. The
results of tests for moisture content shall be used to adjust the added
water in the control of the grout mixing.
d. Moisture Content Corrective Action - Whenever the moisture content
of the fine aggregate changes by 0.5 percent or more, the scale
settings for the fine-aggregate batcher and water batcher shall be
adjusted (directly or by means of a moisture compensation device), if
necessary to maintain the specified flow.
3.6.2.2
Coarse Aggregate
a. Grading - At least once during each shift in which the coarse
aggregate is being placed in the forms, there shall be a sieve analysis
in accordance with ASTM C 136 for each size of coarse aggregate. The
coarse aggregates shall conform to the requirements found in paragraph
COARSE-AGGREGATE GRADING. The location at which samples are taken may
be selected by the Contractor as the most advantageous for production
control. However, the Contractor shall be responsible for delivering
the aggregate to the forms within specification limits. A test record
of samples of aggregate taken at the same locations shall show the
results of the current test as well as the average results of the five
most recent tests including the current test. The Contractor may adopt
limits for control which are coarser than the specification limits for
samples taken at locations other than as delivered to the forms to
allow for degradation during handling.
b. Corrective Action for Grading - When the amount passing any sieve
is outside the specification limits, the coarse aggregate shall be
immediately resampled and retested. If the second sample fails on any
sieve, that fact shall be reported to the Contracting Officer. Where
two consecutive averages of five tests are outside specification
limits, the operation shall be considered out of control and shall be
reported to the Contracting Officer. Aggregate placement shall be
stopped and immediate steps shall be taken to correct the grading.
3.6.2.3
Quality of Aggregates
The quality of aggregates shall meet the following requirements.
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NOTES: Tests should be those listed in paragraph
QUALITY.
SECTION 03372
Page 31
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