Note: Descriptions are shown in the official language in which they were submitted.
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P. 2
PIhEFABR1CATLU CONCRETE PANEL
BACKGROUND OF THE tNVENT1UN
The present invention relates to the fteid of construction and more
particularly, relates
to precast wncrete panels.
'fhe use of precast concrete panels as a component in a building structure is
well
known in the art. Such precast panels are commonly used as components for
floors, walls,
roofs, etc.
The use of profabricetted or precast compo~nts in the erecti on of a but f
ding structure
is desirable for many different reasons. Thus, the conventional method of
wnstructing
concrete floors is relatively lengthy and expensive. Furthermore) variables
such as
temperature and material quality are sometimes difficult to control. The use
of prefabricated
components considerably aids the planning process as factors such as weather
and the like do
not need to be taken into aecount~ For this reason, it is particularly
considered advantageous
in climates wherein weather is such that wrtstruction could not proceed during
certaizr parts
of the year.
As aforementioned, such prefabrie;ated panels are known in the arl. There is,
however, always a need to provide prefabricated concrete panels which offer
desirable
structural characteristics including as low a weight as possible for a given
strength. It is also
desin;ble to have a prefabricated concrete panel which can servo as a floor
slab wherein the
thickness at the supparied edges is minimized to thereby allow a greater
control aver the
height of each level of the building.
SUMMARY OF THE 1NVFNTION
It is therefore an object of the present invention to provide a prefabricated
concrete
panel having a high strength to weight ratio.
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Tt is a fiuther object of the present invention to provide a prefabricated
concrete panel
which can be used in various building structures while maintaining the
thickness of the panel
at its edges to a minimum.
1t is a further object of the present invention to provide a building
structure using
prefabricated concneie panels.
According w one aspec,-t of the present invention, there is provided a precast
concrete
panel compnsmg a slab having first aad second opposed ends and first and
second opposed
sides, an upper surface and a Lower surface, at least one web extending
downwardly from the
lower surface, a tension bar extending from the first end to the other end of
the slab, the
tension bar having a central portion extending downwardly into the web, at
least one
compression bar extending through the slab from the one end to the other end,
the
compression bar and the tension bar being secured together at their respective
ends, and
reinforcing means within the concrete slab.
According t« a further aspect of the preserrt invention, there is provided a
precast
concrete panel comprising a rectangular slab having firs! and second opposed
ends and first
and second opposed sides, an upper surlace and a lower surface, first and
second webs
extending downwardly from the lower surface, the first and second webs being
general ly
parallel to the first and second opposed sides, and a plurality of tension
bars extending from
the first end to the other end of the slab) each of the tension bars having a
central portion
extending downwardly into at least one of the webs, a plurality of compression
bars
extending through the slab from the one end to the other end, oath of the webs
terminating
inwardly from the first and second opposed ends to thereby provide a web free
edge portion
extending atvng the first and second opposed ends, and reinforcing means
within the concrete
slab.
2
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The prefabricated concrete panel ac;c;vrding to the present invention is
generally
designed to be used as a floor slab in any suitable structure. In particular,
the prefabricated
concrete panel can be used in such structures as parking garages as well as in
residential and
commerc,-iallindustrial construction.
The prefabricated concrete panels according to the present inventian may have
various dillerent sties and conhguratfons with a conventional confil,~uation
being a
rectangular one. The prefabricated panels may be formed in various different
lengths and
widths with a typical length being in the order of 7 - 8 meters and a typical
width being in the
order of 2 -3 meters. Naturally, other dimensions may be employed.
The prefabricated concrete panel of the present invention uses at least one
web and
preferably at least a pair of webs which extend downwardly ftvm a bottom
surface of the
panel and which are designed w provide the desired structural reinforcing
characteristics to
the panel.
In a preferred ernbudiment of the present invention, the web or webs do not
extend the
full lenbrth of the panel. Rather, for a substantial portion of the length of
the pre .fabricated
concrete panel, the web or webs have a substantially constant height) However,
as the webs
approach the panel mils, they extend upwardly to merge with the bottom surface
preferably
at an angle of between 30 and 60 degrees and even more pr~eterably at an angle
of about
45 degrees. The webs than terminate shart ofthe ends of the panel. This
structure is
advantageous since the ends of the panel are then free to rest on suitable
supports such as
steel I-beams with only the minimal thickness at the panel ends. In other
words, by utilizing
such an arrangement, the panel can reduce the height of the floor by up to
half a meter.
Fn order to provide the desired structural characteristics, the reinforced
concrete panel
utilizes both tension rods and compression rods.
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1
'fhe compression rods preferably run substantially from one end of the panel
to the
other in a generally straight line.
The tension rods also r~ from one end to the other end of the panel, but are
designed
w substantially follow the form of the web. Thus, each tension rod would
extend from a first
end ofihe panel and then would extend downwardly to follow the general contour
of the web
before terminating at the other and of the panel.
The tension rods and compression rods are preferably secured together at the
panel
ends. A convenient way o1'securing the tension rods and compression rods
together
comprises the use of angle irons located at the ends of the prefabricated
concrete panel. The
angle items may then also be used for securing the panel to the steel support
structure by
welding.
As is well known in the ari, reinfure;ing means within the concrete slab may
be
utilize, such reinfun;ing means including tabors or a wire mesh.
The reinforcing wire mesh may also be employed within the web or webs. Again,
the
use of such reinforcing meshes is known in the art and such meshes are readily
available un
the commercial market.
In a preferred aspect of the present invention, at least a pair of such wire
meshes are
employed. An upper mesh acts in a conventional manner while a lower mesh is
provided and
which lower mesh extends downwardly into the webs - i.e. they would have a U-
shaped
cross sectional wnfiguration substantially identical to that of the webs.
Preferably, the
tension burs would be placed within the U-shaped portion of the wire mesh.
Vlihen employed, the lower mesh would also have reinforcing bars extending at
the
point where the mesh extends downwardly into the webs. Such reinforc,-ing bars
would
normally act in compression. When the web is lifted, these reinforcing bars
then function as
tension bars.
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According to the present invention, there may be provided means associated
with the
prefabricated concrete panel for lifting the same. To this end, there may be
provided a
pl urality of bars extending from above the top surface of the slab downwardly
and looped
around the tensioning bars in the bottom of the web or webs. Preferably, the
lifting members
are themselves formed as a loop at the top for convenience i» lifting. Once in
place, the
lifting bars may be cut.
In a further aspect of the present invention) there is provided an improved
parkin6
garage utilizing the prefabricated and prestressed concrete slabs or panels.
1n a conventional
arrangement, such concrete slabs usually- span the ful l width of a parking
concourse
{approximately 2d meters) and main bCams are parallel w the circulation lane.
Tn the present design, the main supporting beams are perpendicular to the
circulation
lane and the prelabricaoed concrete slabs are parallel to the circulation
lane. This penhits one
to reduce the span of the slab and thus lower the cost-
BRIEF DESCRIPTION OF'fHE DRAWINGS
Having thus generally described the invention, reference will be made to the
accompanying drawings illustrating an embodiment thereof, in which:
Figure 1 is a perspec,-tive view of a precast wncrete panel according to the
present
invention;
Figure 2 is a side elevational view thereof with the precast cpncrete panel
being
supported on a pair of beams;
Figure 3 is a cross sectional view taken along the line 3-3 of Figure 2;
Figure 4 is a detail view of one end of the precasrt concrete panel of Figure
2; and
figure 5 is an end view of a portion of the precast concrete panel
illustrating the use
of angle irons for attaching the reinforcing bars; and
Fibre 6 is a set,~titmai view showing a lifting member.
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1
Referring to the drawings in greater detail and by reference characters
thereto) there is
illustrated in Figure 1 a precast concrete panel which is generally designated
by reference
numeral 10.
Precast cornrete panel 10 includes a first end 12) a second opposed end 14, a
first
side 16, and a sewnd side 18. The configuration is that of a rectangular slab
which has an
upper surface 20 and a lower surfac-x 22.
Extending downwardly from lower surface 22 are a pair of downwardly depending
webs 24 and 26. As each web is substantially identical) only one will be
described herein.
As may he seen in Figures 2 and 3, downwardly extending web 24 has) in
transverse
cross sectional view, a pair of web side walls z8 and 30 which are angled
inwardly slightly
and meet at a web bottom wall 32. fhe web 24 thus has a somewhat IJ-shaped
cross
sectional configuration_
As may be seen in Figures 1 and 2, downwardly extending web 24 has an end wall
33
which is angled so as to extend from lower surface 22 to web bottom wall 32.
It wi l l he
noted that web end wail 33 meets lower surface 22 at a point spaced inwardly
from first
end 12 to thereby provide an edge portion 35. A similar configuration exists
at the other end
of downwardly depending web 24_
'turning to rigure 3, it will be seen that concrete panel 10 includes a
plurality oi'
compression bats 34 which generally extend from first end 12 to second end 14.
A plurality of tension bars 3b also are provided within concrete panel 10;
each tension
bar 36 extends from first end t 2 to second end 14; however it wi 11 be seen
that each tension
bar 36 has, adjacent to first end 12, an upper horizontal portion 38 and a
downwardly angled
portion 40 and a lower horizontal portion 42. 1n other words, each tension bar
36 follows the
general outline or configuration of downwardly depending webs 24 and 26,
6
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I
Concrete panel 10 also includes an upper reinforcing mesh 44 and a lower
reinforcing
mesh 46. in this respect, attd as may be best seen in rigure 3, lower
reinforcing mesh 46
includes horizontal portions 48 and U-shaped portions 50 and 52. il-shaped
portions SU
and ~2 fUlIUW the configuration of downwardIy depending webs 24 and 26
respectively. It
will be noted that tension bars 36 are within U-shaped portions SQ and 52.
In the illustrated embatiment, there are also provided reinforcing bars 54
extending;
from first end 12 to second end 14 and are adjacent or slightly below lower
mesh 46 at the
points where lower mesh 46 makes the transition from horizontal portion 48 to
U-shaped
portions 50 and 52. Reinforcing bars S4 normally act in compression; however,
when the
panel is lilted, they function as tension bars.
Turning to figures 4 and S, it will be seen that at fi~-t end 12) there is
provided a firs!
angle iron 58 ht~ving a vertical portion 60 and a horizontal portion 62. A
second angle
iron fi4 also has a vertical portion 66 and a horizontal portion 68.
Horizontal portions 62
and 68 are positioned at the lower surface 22 of concrete panel 10)
Mgle irons 58 and 64 function as a means of securing compression bars 34 and
tension bars 36 together. Thus, as may be seen, a tension bar 36 is positioned
between
vertical portions 60 and 66 and which tension bar may then be secured by
weldins. A pair of
compression bars 34 ate located at the inner angle of each of angle irons 58
and 64 and
welded thereto.
As seen in Figure 4, the arrangement of concrete panel 10 with downwardly
depending web 24 and edge portion 35 is such that edge portion 35 may sit on
the upper
flange 72 of an 1-beam 74. In turn) the bottom surface of horizontal portions
62 and 68 of
ankle irons 58 and 64 respectively may be welded to the top surface of upper
riange 72.
For purposes of lining precast concrete panel 10 into a desired position, the
panel may
include » plurality of lifting members, one of which is illustnrted in Figure
6 and generally
Feb.l1 '9B 10:56 CA 02222940 1998-02-12 p, g
designated by reference numeral 80. Lifting member 80 is formed as a loop with
a bottrnn
Icnap portion 82 thereof extendinb around one or more tension bars 36 a~ with
a clr~sed loop
upper portion 84 of lifting member 80 extending above upper surface 20.
It will be understood that the above described embodiments are for purposes of
iiluslration only and that changes and modifications may be made thereto
without departing
from the spirit end scope of the invention.
