Construcción
ConstrucciónConstrucción
Construcción
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STRUCTURESTRUCTURE
STRUCTURE
must be thoroughly sealed to prevent any further
damage to the plywood.
• Any cut edge of the plywood should be sealed as
soon as possible, because cut edges soak up
water from the concrete and swell, thus
increasing in thickness.
• In general, it is not recommended to use nails or
screws on the plywood.
• For storage, the panels should be stacked one on
top of the other, placing wood runners between
them. Use some sort of support to separate them
from the ground, and provide shelter. Prolonged
sun and rain exposure damages the panels.
6.1.3.2. Release agent
• Release agent helps separating the formwork
from the concrete, and thus increases the
number of uses and the life span of the panel in
general.
• It plays an important role for the quality of the
concrete finishing because it prevents holes from
air bubbles on the concrete surface and provides
a uniform colour.
• Apply the release agent uniformly and in thin
layers onto the panel, bearing in mind at all times
the instructions for correct use.
• Thoroughly clean the panel surface before
applying the release agent on it.
• Clean the metal frame and the panel off the
release agent after every 4 to 5 uses.
6.1.3.3. Concrete placement and compaction
• Comply with the maximum pressures according
to the instructions of the respective formwork
system.
• Continuously check the state of the formwork
during concrete casting. Stop further casting in
case of any incident.
• Place the concrete in uniform layers of 30 to 45
cm.
• For vertical concrete placement, cast the concrete
from the least height above the formwork
possible. Do never exceed 2 m height unless a
pipe or tube or any similar accessory is used to
channel the concrete. Deposit the concrete as
near as possible to the formwork base, centring
on one point without casting directly against the
formwork.
• When casting with bucket, take special care of
not hitting the formwork, and of complying with
the maximum load-bearing capacity of the crane.
• Avoid concrete splashes on the plywood as these
will reflect on the finished surface.
• Use the appropriate method for concrete
consolidation and compaction depending on the
concrete consistency and its workability.
• The preferred consolidation and compaction
method for wet cast-in-place concrete are poker
vibrators. Use external vibrators only when the
concrete cannot be accessed with poker vibrators
and for parts moulded already in the workshop.
External vibration requires a specific analysis.
• Completely immerse the poker 10 to 15 cm into
the concrete, and put it into each area of
concrete, only once. When concrete is poured in
layers, place the vibrator into the previous layer
to meld the two layers together.
• Never allow the vibrator to touch the formwork
to prevent exceeding the considered loads.
• Immerse vertically or slightly inclined and quickly,
but withdraw slowly.
6.1.3.4. Concrete curing and formwork stripping
• Check that curing is sufficiently advanced for
stripping without causing spalling at the concrete
surface which destroys the finishing and can
affect the strength and durability of the concrete.
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