 Slabs with incline greater than 10%
present a special challenge. Many workmen find it
difficult to visualize the placement volume as steeper
slope is encountered. Incline greater than 100% requires
safety harness in order to even stand in the work area.
Concrete becomes unstable, shifting downward when it is
disturbed by hand work. Vibration causes the slab to
avalanche out of control. These issues prevent the use
of vibratory screeds and cause hand screeds to be very
labor intensive. Most builders believe it is impossible
to maintain flatness tolerance without the use of a
channel paver or a Bunyan Striker.The Bunyan Striker is used in placeme nt
function as the tube sweeps upward, carrying the high
material forward. Workmen read the cut made by the
placement pass and continue delivery to keep the slab
full ahead of the tube. Once the slab area is filled and
the excess is cut away, a screeding pass is made. This
cuts a small roll of fine material in an upward sweep.
This brings the surface grade to a beautiful, uniform
consistency but the instability of the slab will not
tolerate any hand tooling! The Bunyan Striker Tube is
then driven back to the bottom of the slab to begin a
skid pass. This third step is used to dress the slab as
a float, with no rotation. This provides a flat and
floated surface with a slight feathered texture. It is
important to avoid any hand tooling on this slab for
about twenty minutes. After the body of the slab has
stabilized, tooling may be applied without spoiling the
surface grade.
 |
Conic Slabs
Cone shaped slabs and warped slabs require the Bunyan
Striker to be operated on a side hill incline. The
traditional conic basin of a silo is done with the cold
end of the tube fastened at a pivot point in the bottom
center. The top end is supported on a radial form. |
|
Slabs with incline greater than 10%
present a special challenge. Many workmen find it
difficult to visualize the placement volume as steeper
slope is encountered. Incline greater than 100% requires
safety harness in order to even stand in the work area.
Concrete becomes unstable, shifting downward when it is
disturbed by hand work. Vibration causes the slab to
avalanche out of control. These issues prevent the use
of vibratory screeds and cause hand screeds to be very
labor intensive. Most builders believe it is impossible
to maintain flatness tolerance without the use of a
channel paver or a Bunyan Striker.
