degrees C 32 degrees F until after the ambient air temperature rises to
above 0 degrees C 32 degrees F and is expected to remain above 0 degrees C
32 degrees F until the end of the curing and protection period, or until
covered by another lift.
3.2.5.2
Placing During Rain
RCC shall not be placed during rainfall of 2.5 mm/hr 0.1 inch/hr or more.
During periods of lesser rainfall, placement of RCC may continue if, in the
opinion of the Contracting Officer, no damage to the RCC is occurring.
Work shall commence only after excess free surface water and contaminated
paste or RCC have been removed and the surface has gained sufficient
strength (no less than 4 hours after the RCC placement was suspended) to
prevent rutting, pumping, intermixing of rainwater with the RCC, or other
damage to the RCC. When the RCC surface has been contaminated or damaged
in any manner, the RCC surface shall be washed to break up and remove
laitance and/or mud-like coatings from the surface. Any undercut coarse
aggregate shall be removed. All waste shall be removed and disposed of in
an approved manner.
3.2.5.3
Hot-Weather Placement
**************************************************************************
NOTE: Refer to the concrete materials DM for use of
the optional sentences and the correct placing
temperature.
**************************************************************************
In hot-weather placement the temperature of the RCC shall be controlled so
that it does not exceed [25] [_____] degrees C [75.0] [_____] degrees F
when placed. Placement shall be suspended as soon as the RCC temperature
exceeds [25] [_____] degrees C [75] [_____] degrees F. Measures that can
be taken to prevent temperatures exceeding [25] [_____] degrees C [75]
[_____] degrees F include, but are not limited to, chilling mixing water,
sprinkling aggregate stockpiles, use of a canopy to shade the RCC placement
areas, placing during nighttime and early morning hours, or restricting
placements to cloudy days. Use of any of these systems shall not be reason
for extension of completion dates specified in these specifications. [In
addition, to prevent potential damage to the RCC due to hot-weather related
placement conditions, all RCC operation shall be suspended between [_____]
[June 15th] and [October 31st] [_____]].
3.2.6
Surface Preparation
3.2.6.1
Cleaning
All lift surfaces including any RCC, dental concrete, bedding concrete,
bedding mortar, or other conventional concrete placed adjacent to and at
the same time as the RCC shall be cleaned prior to placing any additional
concrete thereon. After cleaning, bedding concrete and bedding mortar are
to be used specifically for achieving bond between different types of
concrete and/or foundation and eliminating and preventing segregation or
voids along margins or RCC placements. No surfaces to receive bedding
concrete or bedding mortar shall be covered with RCC until the prepared
surfaces have been accepted in writing and that acceptance has been
recorded on an approved checkout form. All surfaces upon which RCC or any
bedding mortar or bedding mix is placed shall be moist (but contain no
visible free water). Prior to placing any concrete adjacent to and at the
same time as the RCC, all surfaces shall be clean and free of loose,
SECTION 03701
Page 46
Previous Page
