A variety of other methods of connecting
the panels are also used. A BUTTED con-
nection, using grout or a gasket, can be
used if the wall does NOT contribute any
structural strength to the structure. Steel
columns are welded to steel angles or plates
secured in the wall panel. Precast columns can
also be used. Steel angles or plates are secured in
both the columns and plate and welded together
to secure the panel.
When panel connections that do not actually
hold the panels in place are used, the panels
are generally welded to the foundation and
to the roof by using steel angles or plates.
All connections must provide waterproof joints.
This is accomplished by the use of expansion joint
Tilt-up panels may be finished in a variety of
ways similar to any other concrete floor or wall.
Some finishes may require the panel to be poured
face up; others will require face-down pouring.
This may affect the manner in which the panels
are raised and set.
CONCRETE CONSTRUCTION JOINTS
Construction joints are divisions between
concrete work done at intervals spaced widely
enough to allow partial hardening. They are
used between the units of structure and placed
where they will cause the minimum amount of
weakness to the structure. It is safe to assume that
construction joints are located where the
shearing stresses and bending moments are
relatively small or where the joints will be
supported by other structural members. For
horizontal work, such as floor slabs, construction
joints should be in a vertical plane; whereas, for
vertical work, such as columns, the joints should
lie in a horizontal plane (fig. 7-20).
Foundation walls are bonded to footings with
vertical reinforcing steel called dowels, which
are placed in footings and extend about 3 to 4 ft
up into the wall. A wedge-shaped through, called
a keyway, is built into the footing to strengthen
the bond between footings and walls (fig. 7-21).
The purpose of contraction joints is to
control cracking caused by temperature changes
Figure 7-20-Location of construction joints in beams, columns, and floor slabs.