after final compaction of the several layers by the vibratory roller,
result in the specified lift thickness. During the spreading process, the
dozer operators shall continuously work the RCC surfaces with the dozer
blade and grousers in a manner to remix any RCC that may contain pockets of
segregated material and to compact the material. All surfaces of each
layer shall receive at least two passes with the grousers. The dozers
shall be operating continuously during the spreading process, even if this
action results in more than two passes. A front-end loader with operator
shall be available to assist with depositing and spreading RCC as needed in
confined areas, at the abutments, and at other locations approved or
directed. In no case shall the RCC, bedding mixes, or bedding mortar be
allowed to dry. Under no conditions shall a dozer or other tracked vehicle
be operated on other than fresh uncompacted RCC except at the start of each
lift placement to facilitate startup operations, and then only by an
approved procedure. No RCC or other concrete shall be placed on a previous
lift which has not met specification. Unacceptable material shall be
removed.
3.3.6
Compaction/Consolidation
After spreading and working with the dozers, the top surface of each lift
shall be compacted with a minimum of four, plus as many additional passes
with a self-propelled double-drum vibratory roller operating in the
vibratory mode as are required to obtain a minimum of 98 percent of the
theoretical density. A round trip over the same material shall count as
two passes (i.e., from point A to point B and return to point A by the same
route is two passes). Rollers shall not be operated in the vibratory mode
unless they are moving. Bedding concrete and any other conventional
concrete that interfaces with the RCC shall be consolidated with internal
vibrators.
3.3.6.1
Theoretical Density (TD) Determination
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NOTE: See the appropriate DM to fill in the blanks.
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The TD is defined as the theoretical density (unit weight) of the concrete,
kg pounds per cubic meter foot, computed to include an air content of
[_____] percent. The TD value to be used during construction will be
determined using job mixture proportions and Contractor supplied materials;
and, using compaction techniques suitable for RCC, and following the
appropriate testing procedures used to determined theoretical unit weight
of concrete as described as in ASTM C 138/C 138M.
3.3.6.2
Required Compaction Density
All RCC shall be compacted to a minimum of 98 percent of the TD value.
The
anticipated TD, estimated from laboratory test data is approximately
[_____] kg pounds per cubic meterfoot.
3.3.6.3
Density Determination of Compacted RCC
Density shall be measured using a nuclear density meter in accordance with
ASTM C 1040. RCC density value determinations shall be made throughout the
course of RCC placement to assure that the RCC is compacted to a minimum 98
percent of the TD and detect segregation and/or voids throughout the RCC.
SECTION 03701
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