|
The surface should be covered promptly after
final finishing with a single, clean layer
of wet burlap. Immediately following the
covering of wet burlap, a layer of polyethylene
(preferably white) film should be placed
over the wet burlap. The coverings should
remain until the RSLMC has reached a strength
desired for initial traffic loading. Depending
on temperatures, and specified strength,
this will usually be within 1 - 6 hours
after the pour. The surface of the RSLMC
should remain wet for this time period.
Additional water may need to be applied
to the burlap during the curing, as the
surface of the concrete will tend to dry
out under the wet burlap.
LIMITATIONS
Traffic Loading: No vehicular traffic
should be permitted on the RSLMC
until an early bearing strength has been
achieved. This can be verified by making
field cast test cylinders, and protecting
them from adverse temperatures. An unheated
foam curing box is recommended during a
cold weather pour.
Cold Weather: (Below 50°
F): RSLMC should not be placed if temperatures
will not be above 45° F for the duration
of the pour and initial curing period. Provisions
will have to be made to ensure that the
RSLMC has an initial temperature
above 60° F. During the curing phase,
the covering of polyethylene should be replaced
with an approved insulation blanket. All
other aspects of the curing section should
be followed. Also see ACI 306, " Recommended
Practice for Cold Weather Concreting" for
further guidance.
Hot Weather: (Above 80°
F): During periods of hot weather, RSLMC
can be mixed with citric acid to extend
working time. Consult your local CTS Representative
for appropriate doses. When daytime conditions
produce temperature in excess of 85°
F, or when daytime conditions of temperature,
wind, and humidity cause an evaporation
rate greater than 0.15 lbs/sf/hour, consideration
should be given to night placement. Also
see ACI 305, " Recommended Practices for
Hot Weather Concreting" for further guidance.
|
