permit the above water spray, hand-held fog spraying shall be applied to
the concrete surfaces as directed to prevent drying out of concrete
materials and replace moisture lost to evaporation. These hot-weather
protection procedures will require additional labor(s) to assure complete
coverage of the entire surface areas to prevent unacceptable damage to the
RCC and conventional concrete.
3.5
VERTICAL FACINGS FOR RCC CONSTRUCTION
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NOTE: See the concrete materials DM to select the
appropriate method or methods specified below. It
should be noted that the method used for other
vertical conventional concrete work may be different
from the method used for construction of the
upstream face. See paragraphs GALLERY, SPILLWAY
CONSTRUCTION, etc.
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The vertical faces of the RCC structure are to be constructed using [a form
and cast-in-place conventional concrete system] [a slipform facing system]
[a precast concrete panel system] as shown and specified. The vertical
facings system shall be demonstrated on one side of the RCC test section.
3.5.1
[Form and Cast-in-Place Conventional Concrete
Vertical and near-vertical facings shall be as shown in the drawings. The
contract drawings are based on designs whereby all vertical and
near-vertical faces are constructed of conventional slump concrete at the
same time and rate as used in placement of each RCC lift. In construction
of vertical facings, a 0.75 to 1.25 meter 2.5 to 4.0 foot wide zone of
conventional concrete shall be placed against the forms or other hard
surface. The design and engineering of the formwork, as well as its
construction, shall be the responsibility of the Contractor. The formwork
shall be designed for loads, lateral pressure, and allowable stresses in
accordance with Chapter 1 of ACI 347R. Forms shall have sufficient
strength to withstand the pressure resulting from placement and vibration
of the concrete and shall have sufficient rigidity to maintain specified
tolerances. The required sequence of construction operations after all
forms and concrete surface preparations have been approved is: place
conventional concrete full height of each RCC lift and full width against
the forms; using dozer action, spread each thin RCC layer into and abutting
against the conventional concrete while at the same time tracking the
interface between the two with dozer grousers; after full-lift thickness of
the RCC is in place next to the conventional concrete, consolidate 100
percent of the conventional concrete and the interface; and finally,
compact the RCC (to include the interface) using the vibratory roller. The
interface between the RCC and conventional concrete shall be consolidated
and "knitted" together using the gang heavy-duty, machine-mounted,
immersion vibrators. Extreme care shall be taken to stage activities to
assure all time restrictions are met and to prevent the occurrence of any
openwork, honeycombing, or voids at the conventional concrete/RCC
interface. All conventional concrete and bedding concrete placed along the
RCC and the interface shall be thoroughly consolidated and intermixed by
use of immersion vibrators. The Contractor's construction techniques and
equipment used shall be satisfactorily demonstrated during construction of
the test section.]
SECTION 03701
Page 53
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