3.3.1
Procedures
It is the intent of this contract to raise the structure at essentially the
same level across the entire horizontal surface area. For a dam, placement
Each lift shall be completed in its entirety across the full surface of the
mass. As the advancing edge of the lift progresses, the exposed leading
edges shall be kept "live" by progressively placing out from the advancing
edge in a sloping and uniform fan-like manner. RCC shall be deposited
(from the conveyor, end-dump truck, or front-end loader) on the uncompacted
RCC of the advancing edge in a forward direction from the dump pile. RCC
shall not be placed in consecutive or consistent lanes. The dump location
shall be varied to avoid "lane" construction. [See Contract Drawing
[_____] showing typical depositing, spreading, and remixing operations.]
The interval between batch plant mixing and final RCC compaction shall be
no greater than 45 minutes for 300 mm 12 inch lifts and 75 minutes for 600
mm 24 inch lifts. Final compaction is defined as: Any RCC lift composed
of layers that have been worked twice by dozer grousers, receives four
passes with the vibratory roller, and meets the density requirements.
3.3.2
Bedding Mortar
The bedding mortar shall be applied to the existing surface following any
required cleanup. The bedding mortar shall be applied not more than 15
minutes ahead of RCC placement, unless otherwise approved. The bedding
mortar shall be used between hardened conventional concrete and RCC,
between different RCC placements where cold joints occur, and other
locations as directed or as shown in the drawings. The bedding mortar
shall have an average thickness after application of between 6 and 13 mm
1/4 and 1/2 inch and shall cover 100 percent of the lift area.
3.3.3
Bedding Concrete
The bedding concrete, a conventional concrete mixture, shall be used at the
abutment-RCC interface, and except for cast-in-place concrete for the
upstream face, between the RCC and any formed sloping or vertical surface
and other locations as directed or as shown in the drawings. Placement of
the bedding mixture shall occur only after all required surface
preparations have been completed.
3.3.4
Lift Thickness
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NOTE: See the concrete materials DM for the lift
thickness.
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The total lift thickness after final compaction by the vibratory roller
shall be [300] [_____] mm [12] [_____] inches.
3.3.5
Depositing, Spreading, and Remixing
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NOTE: See the appropriate Design Memorandum for use
of the alternate optional paragraphs below.
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After the RCC has been deposited, the RCC shall be spread by dozers into
gently sloping layers, approximately 150 mm 6 inches thick, that will,
SECTION 03701
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