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The method used in disposing of waste water employed in cutting, washing,
and rinsing of concrete surfaces shall be such that the waste water does
not stain, discolor, or affect exposed surfaces of the structures, or
damage the environment of the project area. The method of disposal shall
meet all requirements of Section [[_____]] [_____].
3.3
TRANSPORTING AND PLACING
3.3.1
Transporting
Methods and equipment for conveying and depositing the concrete into the
form shall be subject to approval. The capacity of the transporting system
shall be sufficient to supply concrete at a rate to prevent cold joints
forming during placement. A properly designed and sized elephant trunk and
rigid drop chute bottom section which will prevent free-fall within the
elephant trunk and rigid drop chute will be used if concrete is to drop
more than 1.5 m 5 feet. If concrete is to be placed through installed
horizontal or sloping reinforcing bars, the concrete shall discharge into a
pipe or elephant trunk that is long enough to extend through the
reinforcing bars to within 1.5 m 5 feet of the placing surface. In no case
will concrete be discharged to free fall through the reinforcing bars.
3.3.1.1
Transporting by Bucket
There shall be provided indicating and signaling devices for the control of
identification of types or classes of concrete as they are mixed and
discharged into buckets for transfer to the forms. Each type or class of
concrete shall be visually identified by placing a colored tag or marker on
a bucket as it leaves the mixing plant so that the concrete may be
positively identified in the forms and placed in the structure in the
desired position.
3.3.1.2
Transporting by Pump
The nominal maximum-size coarse aggregate will not be reduced or mixture
proportions changed to accommodate a pump except as specifically determined
appropriate. The distance and height to be pumped shall not exceed limits
recommended by the pump manufacturer. The concrete shall be supplied to
the pump continuously. When pumping is completed, concrete remaining in
the pipeline shall be ejected without contamination of concrete in place.
After each operation the equipment shall be thoroughly cleaned and flushing
water shall be wasted outside the forms.
3.3.1.3
Transporting by Belt Conveyor
Methods and equipment for transporting the concrete by belt conveyor into
the form shall be subject to approval.
3.3.2
Placing
The capacity of the placing system shall be sufficient to supply concrete
at a rate which will prevent cold joints in any placement. Concrete shall
be worked into the corners and angles of the forms and around all
reinforcement and embedded items without permitting the material to
segregate. Concrete shall be deposited as close as possible to its final
position in the forms, and in so depositing, there shall be no vertical
drop greater than 1.5 m 5 feet except where suitable equipment is provided
SECTION 03700
Page 58
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