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BACKGROUND OF THE INVENTION
Concrete tilt up walls have been used for a fairly long period of time in
the construction industry. Construction of tilt up walls of the type
contemplated has, however, been beset by a number of problems. Tilting up
of concrete slab walls is difficult because of the very heavy weights of
the wall slabs. Once the concrete slabs have been moved to upright
condition, keeping them there has also been a problem. Removal of the
forms from the poured and set slabs presents additional problems.
Construction of the form for the walls has been time consuming and costly,
and often the forms cannot be used repeatedly, but must be constructed
specially for the wall slab to be poured. When the slabs are poured away
from the job site, transportation and handling difficulties are
encountered. This invention seeks to provide methods and apparatus for
forming concrete wall slabs of reduced cost, of reduced weight, and
without the problems mentioned above, and others.
SUMMARY OF THE INVENTION
The invention provides methods and apparatus for construction of concrete
tilt up wall slabs, and for their erection. Modular form pans are disposed
on guide bars which properly locate and interconnect the pans into a
complete form for a concrete wall panel. The complete form includes
surrounding members which tie the whole assembly together and complete the
form.
After concrete has been poured to fill the form, the form elements are
removed from the concrete wall panel, and can be reused in additional form
assemblies. The concrete panel is equipped with connection units so that
it can be easily handled and propped up in vertical disposition for
assembly into a complete building structure.
The modular pans create regular indentations or recessed areas in the
concrete wall panel, reducing its weight so that it may be readily lifted
and positioned, yet not reducing its strength and utility. The recesses
may be disposed at ether the inside or outside of a building wall.
The recesses contribute to considerable savings in the amount of concrete
required, and the rapid assembly and disassembly of the forms greatly
reduces construction time, effort and cost. The form elements are adapted
for use with walls of differing dimensions, so can be used for a variety
of building designs.
A principal object of the invention is to provide methods and apparatus for
construction of tilt up concrete wall panels. Another object of the
invention is to provide such methods and apparatus enabling rapid assembly
of wall panel forms, with resultant advantages. Yet another object of the
invention is to provide such methods and apparatus which provide superior
wall panels of reduced weight, great strength, and high utility. Still
another advantage of the invention is to provide such methods and
apparatus, and methods and apparatus for handling of same, in a complete
construction package. Still another object of the invention is to provide
such methods and apparatus which result in concrete wall panels of
improved appearance. A further object of the invention is to provide such
methods and apparatus which are economical, dependable, simple in use, and
superior.
Other objects and advantages of the invention will appear from the
following descriptions of preferred embodiments, reference being made to
the accompanying drawings.
BRIEF DESCRIPTIONS OF THE DRAWINGS
FIG. 1 is a side elevation of a portion of a form pan assembly of preferred
form according to the invention.
FIG. 2 is a top view of the apparatus shown in FIG. 1.
FIG. 3 is a vertical cross section taken at line 3--3 of FIG. 2.
FIG. 4 is a side elevation of a portion of a brace apparatus according to
the invention.
FIG. 5 is a partial cross section showing the manner of use of the appratus
shown in FIG. 4.
FIG. 6 is a vertical cross section showing the method for securing the
concrete wall panels in vertical disposition in a structure.
FIG. 7 is a schematic drawing indicating the method for erecting a wall
panel according to the invention.
FIG. 8 is a side elevation of a connection element provided according to
the invention.
FIG. 9 is an upper perspective view showing the method and apparatus for
connection of a lifting means to a panel according to the invention.
FIG. 10 is a vertical cross section of a portion of the apparatus showing a
modified form of the apparatus.
FIG. 11 is a plan view of another apparatus element according to the
invention.
FIG. 12 is a partial vertical cross section showing another modified
apparatus according to the invention.
FIG. 13 is a side elevation of yet another modified form of apparatus
according to the invention.
FIG. 14 is a schematic side elevation showing an erection method according
to the invention.
DESCRIPTIONS OF THE PREFERRED EMBODIMENTS
Referring now to the drawings in detail, and first to FIGS. 1 and 2, the
preferred apparatus includes a plurality of form pans 10, four being shown
in FIG. 2, one pan being completely shown and three pans being
incompletely shown. Each pan 10 has a surrounding horizontal flange 11,
the flanges of adjacent pans 10 being overlapped, as can best be seen in
FIG. 1. The pans are used in inverted positions, with the flat bottom 12
up, the slanted sides 13 and ends 14 sloped outwardly and downwardly to
the surrounding flange 11. The pans 10 are located and held in position by
a plurality of guide bars 15 which have short lugs 16 welded thereto at
spaced positions along their lengths. The lugs are beveled inwardly at
their upper ends to be easily insertable in circular holes in the flanges
11. Where two pans 10 are adjacently together, the flanges of the two pans
are overlapped and the holes of each are disposed over the same lugs 16.
To assemble a plurality of pans 10 to form a complete form for a wall
panel, the bars 15 are laid on a floor or other preferably flat surface,
spaced parallely by the distance between the holes of the flanges 11.
First, one pan 10 is placed across the bars, with the holes of its flange
11 having the lugs 16 of the bars disposed therethrough. Then, additional
pans 10 are put into place, the flanges 11 overlapped, with the lugs 16
disposed through the holes of the flanges 11, as shown in FIGS. 1 and 2.
Depending on the size of the wall panel to be poured, any number of pans
10 may be assembled on bers 15 to make a form corresponding to the size of
the wall panel desired. After the pans 10 have been assembled on the bars
15, a channel member 18 is set along each side of the outermost pans, and
a Z-bar 19 is set along each end of the outermost pans. At the corners of
the form, the channels 18 and Z-bars 19 are connected by the angle
brackets 20, bolted through holes provided through the channels, Z-bars,
and brackets (see FIGS. 2 and 3).
Next, reinforcing bars 21 are installed, each bar 21 extending through a
hole through a Z-bar at each end and disposed along a trough 22 formed
between the facing side walls 13 of adjacent pans 10 or along a trough 23
formed between a channel 18 and a pan sidewall 13. The ends of the
reinforcing bars 21 are threaded and nuts 24 are screwed thereonto, so
that the Z-bars 19 are held inward and the reinforcing bars are drawn
fairly tight to extend fairly straight through the troughs.
At what are to be the bottom corners of the panels, one or more lengths of
angle irons 25 are set in place inside of the Z-bars in the position shown
in FIG. 6, the angle irons 25 being anchored later in concrete by the
angle rods 26 welded thereto.
The recesses formed in the concrete panel by the pan shape are referred to
by reference numerals 27. The concrete set in the troughs between facing
sides 13 and between a side 13 and a channel 18 are referred to by
reference numerals 28. The beams 28 reinforce the slabs 29 formed above
the pans 10.
The angular members 15a on bars 15, FIG. 3, support tops 12 of pans 10
during concrete pouring.
Referring now to FIGS. 8-9 of the drawings, the fitting 30 shown in FIG. 8
is used in lifting of the panels after they have been poured and set. The
cylindrical body 31 has a tapped opening 32 therethrough adapted for
screwing onto the threaded end of a reinforcing bar 21. As mentioned
earlier, the bars 21 are threaded at their ends to receive the nuts 24.
After the concrete is set in the form, the nuts 24 are removed, and the
corner brackets 20 are unbolted, after which the Z-bar may be removed from
the end of the panel. The fittings 30 each have opposite ends of reduced
diameter, reference numerals 33, each of which has a drilled hole 34
therethrough near its end. The arms 35 of a yoke connector 36 are
perforated to be received over the reduced diameter fitting portions, and
retained by a cotter pin or like stop to prevent arms 35 from removal from
the fitting 30. As shown in FIG. 9, the fittings 30 are screwed onto bars
21 first and second from the sides of the concrete panel, with a fitting
connector 36 fixed to each. Only one pair of connectors 36 is fully shown,
the other pair being indicated schematically by dashed lines 36a. A chain
37 is passed through the opening of an eye bolted to a beam 38 at each
side of the panel. Then the beam 38 may be lifted by a crane or hoist, not
shown, to lift the panel. Since the bars 21 extend through the full length
of the concrete panel, the bar 38 connection to the panel is strong and
not subject to failure, and the crane or hoist can pick the panel
completely off the floor so that the panel can be moved to its proper
location in the structure and can be rotated to present either face toward
the exterior of the structure. The foregoing is possible because the panel
is much lighter in weight than the usual tilt up wall panel, because of
the recesses 27 which eliminate a considerable volume of concrete, and
because of the reliable connection of the crane or hoist thereto. A much
smaller crane or hoist can be used than has been possible with
conventional types of tilt up concrete wall panels.
In FIG. 6, the concrete floor slab on which the wall panel is poured is
indicated by reference numeral 40. A reinforced edge beam 41 has a
downwardly recessed outer edge 42 forming a ledge on which the concrete
wall panels are supported. An angle iron 43 is set and anchored into beam
41 at the inside angle of recess 42, as shown. When the concrete wall
panel is set onto ledge 42, angle iron 25 if the panel abuts angle iron 43
of the beam. After the wall panel is in place, angle iron 25 is welded to
angle iron 43 at 44, securing the wall panel to the ledge.
Referring to FIGS. 4 and 5 of the drawings, as well as to FIG. 3, plastic
inserts 46-48 may be set in place in the form at desired locations. A
plastic tube 49 is coupled to the nipple 50 of insert 48, and a plastic
tube 50 is coupled between the nipples 50 of inserts 46, 47, as shown.
When the concrete is poured and set in the form, the presence of the
inserts and tubes causes recesses 51, 52 to be formed in the beam 28, with
a cylindrical opening 53 through the beam. The inserts 46-48 and the
recesses 51, 52 are, say, 6 to 8 inches long along the length of the beam.
As shown in FIG. 5, a yoke element 54 may be coupled to the beam at the
opening 53 by placing the arms of the yoke at the oposite ends of the
opening and running a pin or bolt through perforations in the yoke arms
and the opening through the beam.
The yoke element 54 shown in FIG. 4 may be connected to a beam in the
described manner. The apparatus shown in FIG. 5 is a brace or prop useful
for holding a wall panel in upright position before it is secured by other
means. The yoke 54, having holes 55 through its arms to receive ends 93 of
bolt 94, is welded to a rod or bar 56 which is outwardly threaded. Bar 56
screws into the internal threads of a fitting 57 which is welded at 58 to
the end of a pipe 59. Pipe 59 has a plurality of holes 60 through its
wall, the holes being in opposite pairs along the pipe and being regularly
spaced along the length of the pipe. Pipe 59 is telescopically received
into a larger pipe 61, which has a pair of opposite holes 62 adjacent its
end. By matching a pair of holes of pipe 59 with the holes 62 of pipe 61,
the pipes can be fixed together by insertion of a bolt through the aligned
holes. By changing to a different pair of holes of pipe 59, the length of
the apparatus can be altered. The length of the apparatus may also be
adjusted by screwing bar 56 into and out of fitting 57, so that the
apparatus length can be made as desired. The right end of the apparatus
the left end of which is shown in FIG. 4, is the same, there being a pair
of holes 62, a pipe 59 with plural spaced pairs of holes 60, a fitting 57,
and a bar 56 at the opposite right hand end of pipe 61. The length
adjustments are, therefore, repeated at each end of pipe 61. The threads
of bar 56-fitting 57 at one end are of opposite pitch so that the
apparatus performs as a turnbuckle.
The yoke arms 54 are placed at opposite sides of a beam 28 which has
recesses 51, 52 formed as shown in FIG. 3, using the plastic inserts 46,
47. A pin or bolt 53a is inserted to connect the beam 28 to the yoke at
one end of the FIG. 4 apparatus. The opposite end of the FIG. 4 apparatus
is anchored in any suitable manner to the floor 40 adjacent the base of
the wall panel, and the FIG. 4 apparatus acts as a prop to hold the wall
panel upright at the proper location and perfectly vertical, as shown in
FIG. 7.
The wall panels, when the Z-bars 19 have been removed from a panel end,
have the ends of the reinforcing bars 21 protruding therefrom. The
threaded ends are used to connect the lifting beam 38 to the panel end
using the bodies 31, as has been described. At the bottom ends of the
panels, the ends of bars 21 interfere with standing of the panel on its
end on ledge 42, so the bar ends must be cut off, usually with a torch,
before the wall panel is elevated to vertical position. The upper ends of
the bars 21 may also be cut off after the panel has been tilted up, if
desired or necessary.
Alternatively, the reinforcing bars may be supported in a different manner
at the bottom end of the panel, according to FIG. 10. As shown in FIG. 10,
the lower ends of the reinforcing bars may be welded, as at 65, so that
cutting off of the bar ends is not necessary before the wall panel is
stood up. However, the bar ends must be allowed to project from the panel
at the upper end of the panel in order that the lifting beam 38 may be
connected as shown in FIG. 9, for tilting up of the panel. At the welds
65, the end of the reinforcing bar 21 is welded to the corner angle iron
25 which is welded to the angle iron 43 set at ledge 42 as shown in FIG.
6.
In FIG. 14, another example of how a panel may be tilted up to vertical
wall position is schematically shown. A longer upper beam 68 is supported
by a cable 69 connected thereto at its ends, cable 69 being engaged by a
hook 70 carried by cable 71 of the boom arm 72 of a crane. The ends of
beam 68 are connected to the centers of two beams 38 by cables or chains
73, 74, details of the connections not being shown, but being
conventional. The two beams 38 are each connected to the wall panel 75 at
the threaded upper ends of reinforcing bars 21 as already described, using
screw on bodies 31 as shown in FIG. 8. As indicated by the drawing, an
entire wall panel for one wall of a building may be tilted up in a single
procedure. The panel 75 is exemplary, only, and the panel may take other
forms. The panel 75 is shown to have windows 76, 77, 78 and door 79, these
being formed in the panel by rectangular inserts placed between pans 10,
the inserts not being shown, but consisting of four side members connected
at the corners by releasable connections such as bolts.
In forming a wall panel such as that shown in FIG. 14, it is likely that
pans 10 of various sizes will be needed to accomodate the pans with
inserts for windows and/or doors or other openings required. Also, the
surrounding rectangular frame outside of the pans may have to be varied in
lengths of the members. In FIG. 13, there are shown a pair of Z-bars 19a,
19b each having a plurality of pairs of spaced holes 81. By overlapping
the Z-bar ends, and using different aligned pairs of the holes 81, the
lengths of the overall Z-bar may be adjusted. By properly spacing the hole
pairs, the length of the Z-bar may be varied in one inch increments, so
that the width of a panel may be varied by one inch increments. By the
method illustrated by the apparatus of FIG. 11, the widths as well as the
lengths of the pans 10 may be varied.
Referring now to FIG. 11 of the drawings, a pan 10, as shown in FIGS. 1-2,
is shown, end to end with a modified pan lOa. Pan lOa is like pan 10,
except that one end 14 is omitted, the pan lOa being open ended. The open
end of a pan lOa can be telescoped over either end or both ends of a pan
10, to variably increase its length. It is, however, necessary to match
the holes in the flanges 11 so that they can be slipped over the lugs 16
of the guide bars 15, in order that the assembly will be held together
properly. If the open ended pan lOa is longer than the pan 10, then the
length of a pan 10 may be increased to more than twice its length, this
procedure increasing the spacings of the horizontal concrete beam portions
of the panel, but in many structures the horizontal concrete beams are not
necessary, anyway. The dashed lines 85 in FIG. 14 indicate the array of
pans 10, 10a which can be used in forming the wall panel. At any rate,
pans 10 may be varied in length, and in width, according to the principal
shown and described. The lengths of the guide bars 15, and the spacings of
the lugs 16, may be varied as desired to accomodate any size all panel to
be formed.
The invention described has many advantages over the prior art. Concrete
wall panels may be made at the job site and easily moved to upright
position for use in a wall.
Referring particularly now to FIG. 12 of the drawings, a channel 86 is
shown at the ends of the pans 10, with a wider than normal flange llc. The
lugs 16 are disposed through openings through flange llc and through
openings through angle iron 25a. The threaded ends of the reinforcing bars
21 extend through openings through angle iron 25a and channel 86, and are
secured by washers 87 and nuts 88. A nailing block 89 is shown set on
flange lla inward of lugs 16 and angle iron 25 a. When concrete is poured
and set in this form, the block 89 will be set in the concrete to provide
a place where objects may be nailed or screwed to the panel. Nailing
pieces may be placed in any desired locations in the panel, such as for
example, around window and door openings, so that standard window and door
frames may be installed in the openings in the standard manner. The wood
pieces may be anchored in the concrete by one or more nails or screws 90
fixed into the piece. It is apparent that a wall panel may be adapted for
whatever connections to it are required or desired.
The air valve 95, FIG. 3, is provided to assist in removal of the forms
from a panel after the concrete has been poured and set. A hose from a
pressured air source can be connected to valve 95, and pressured air
injected into the form to dislodge the form from the concrete.
In FIG. 12, reference numeral 98 indicates a welded steel reinforcing mesh.
The forms herein disclosed may be used in conjunction with any other type
of concrete form. The channels and Z-bars may be replaced by wood planks
or other type of panel apparatus.
It has been estimated that use of the methods and apparatus according to
the invention will result in the following savings: a saving of 60% of
concrete cost; a saving of 80% of steel cost; a saving of 60% of labor
cost; and a saving of 90% of engineering cost. And, the adjustability of
the forms enables making of wall panels of virtually any size and design
with no additonal costs. The panels are very light in weight as compared
with conventional panels, even those conventional panels of so-called
"waffle" design, the forms for which are very expensive.
The preceeding descriptions have pointed up the concept of the invention
and preferred embodiments thereof. The invention provides a new, novel and
useful method and apparatus for making and erecting concrete tilt up wall
panels of substantial value in the industry.
While preferred embodiments of the methods and apparatus according to the
invention have been described and shown in the drawings, many
modifications thereof may be made by a person skilled in the art without
departing from the spirit of the invention, and it is intended to protect
by Letters Patent all forms of the invention falling within the scope of
the following claims.
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