BACKGROUND OF THE INVENTION
Field of the invention
[0001] The present invention generally relates to the art of making a concrete wall which
is insulated both on the inside and on the outside by using a formwork, made of foam
plastic material such as expanded polystyrene, as a mold into which the concrete
mix is poured, which mold is permanently secured to the concrete after the latter
has set.
Description of the prior art
[0002] In present day practice, a formwork made of wood or metal panels held together in
spaced parallel position by tie-wires and other appropriate connection means at their
end, is used to build a concrete wall. The formwork is expensive and its mounting
and dismounting are time consuming and thus also costly, Furthermore, the resulting
concrete wall is not insulated.
[0003] A formwork has already been proposed which is constituted by hollow modules fully
made of insulating foam plastic material; the modules being disposed and stacked in
the manner of a brick wall and concrete mix being thereafter poured into the assembled
hollow modules acting as a mold which remain permanently secured to the concrete wall
after the concrete has set. In this manner, not only is time being saved in setting
up the formwork on site-appropriate tie-wires and tongue-and-groove joints being provided
at the factory-but there is no time wasted in dismantling the formwork as in the
old practice. Also, the very advantageous result is the production of a concrete wall
which is fully and permanently insulated both on the inside and on the outside.
[0004] However, these known insulated formworks suffer severe drawbacks.
[0005] Indeed, because these modules are quite light, they tend to separate from one another
by the pressure built by the concrete mix when being poured. Because of this, elaborate
means must be provided, at the site and outside the formwork, to prevent such separation
caused by lifting of the modules as the latter tend to float on the concrete mix,
because of their lightness.
[0006] Also, the known formworks are built, as said above, from brick-like hollow modules
molded in factory and formed of a pair of foam plastic panel-like sections held in
space relationship by tie-wires or rods of which the ends are solidly embedded in
the foam plastic, at the factory. The result is that a module is useful for making
a concrete wall having only one predetermined thickness. It is therefore necessary
for the manufacturer to keep a large inventory of modules of varying thicknesses to
satisfy customers' demand.
Summary of the invention
[0007] It is therefore an object of the present invention to propose an improved formwork,
of the above type, capable of avoiding the aforesaid drawbacks.
[0008] This is achieved, on the one hand, by manufacturing identical module sections as
separate members rather than immediately connecting them two by two, at the factory,
to produce complete modules; the required tie-wire or rod means being made and supplied
separately. Appropriate provision has to be made, of course, on the module sections
to receive the tie-wire means, but the latter are only applied on the construction
site.
[0009] As will be gathered from the above, this procedure makes it possible to supply always
the same module sections and separate tie-rods thereby appreciably reducing inventory
since only the tie-rods need be of various sizes suited for the desired wall thickness.
By the same token, volume is reduced so that less space is required for storage and
transportation. This result is more specifically achieved by embedding inserts in
the ribs of the module sections, to which reference is fully made hereinafter, which
inserts have apertures into which hooked ends of tie-rods lockingly engage, thereby
holding the module sections in appropriate lateral relationship to form modules.
[0010] Vertical coupling rods having hooked ends are, on the other hand, provided to interlock
with tie-rods of stacked modules to prevent the latter from separating upward under
the pressure built by the concrete mix when the latter is being poured. Thus, there
is no need to provide any additional structure, on the site, to safely hold the modules
in steady vertical position in relation to one another, thus preventing the above
mentioned lifting action.
[0011] More specifically and according to one aspect of the invention, there is provided
a formwork module section, made of foam plastic material, which is adapted to serve
as one wall of a module of a formwork and which comprises a panel, spaced ribs solid
with the panel and projecting from the panel inner face between the panel upper and
lower edges, and inserts embedded, each in one of the ribs, the inserts being formed
with tie-rod receiving-and-locking apertures; these apertures being located at the
upper and lower ends of the ribs short of the panel upper and lower edges.
[0012] According to a preferred form, the inserts may be tubular members having hollowed
ends opening at the ribs upper and lower ends; these hollowed ends defining the aforesaid
tie-rod receiving-and-locking apertures. Alternatively, the inserts may be in the
form of channel-shaped members having ends projecting beyond the ribs upper and lower
ends; these members each having a central web formed with holes located in the projecting
ends, these holes acting as the tie-rod receiving-and-locking apertures.
[0013] Another aspect of the invention is a formwork module which comprises a pair of formwork
sections as defined above, these sections being disposed in mirror position and the
formwork module further comprising tie-rods having hooked ends lockingly engaged into
the insert apertures.
[0014] Still another aspect of the invention lies in a formwork for making an insulated
concrete wall and comprising a pair of modules as defined above, which modules are
stacked one upon the other with adjoining tie-rods disposed one above the other, in
pairs, the formwork further having coupling rods with hooked ends, these hooked ends
interlocking with the tid-rods of the aforesaid pairs for preventing vertical separation
of the formwork modules as concrete is being poured into it.
[0015] Other objects, features and advantages of the invention will become apparent from
the following description having reference to the appended drawings and given purely
as an example as to how the invention may be put into practice.
Brief description of the drawings
[0016]
Figure 1 is a top plan view of two module sections in their mirror position of use,
while Figure 2 is a side elevation view;
Figure 3 is a cross-sectional view of one module section taken along line III-III
of Figure 2 while Figure 3A is an end view likewise of a module section;
Figure 4 is a perspective view of a formwork in the process of being erected, three
modules being shown interconnected;
Figure 5 is a vertical cross-sectional view of the ends of two interconnected stacked
modules, view taken in a vertical plane containing two tie-rods, a coupling rod and
a reinforcing bar support;
Figure 6 is a side view of a coupling rod;
Figure 7 is a view similar to that of Figure 4 showing an alternative embodiment;
Figure 8 is a perspective view of an insert member for the embodiment of Figure 7;
Figure 9 is a view similar to that of Figure 5 but for the embodiment of Figure 7,
and
Figures 10 and 11 are alternative forms of tie-rods in the embodiment of Figure 7.
Description of the preferred embodiments
[0017] Referring to Figs. 1, 2 and 3, there is shown two module sections 1 in their position
of use, that is, in mirror position. Each section 1, made completely of foam plastic
material as aforesaid, comprises a panel 3 having an outer flat face 5 and an inner
flat face 7; an upper edge 9 and a lower edge 11. Elongated evenly spaced ribs 13
project from the inner flat face 7 between the edges 9 and 11 and their upper and
lower ends 15 and 17 preferably slope from the panel edges 9 and 11 toward flattened
tips 19 of the ribs 13, as shown in Figs. 3 and 3A. At least part of each ends 15
and 17 of the ribs 13 forms a flat wall located short of the edges 9, 11, of the panel
3. This may be obtained by cutting appropriate notches 21 and 23 (Figs. 3, 5) through
the sloping ends 15, 17. One insert, in the form of a tubular member 25, is embedded
in each rib 13, its hollowed end opening in the flat walls of the notches.
[0018] As shown, the ribs 13 preferably have vertical curved sides merging with the panel
inner face 7 so that concrete mix poured in the mold formed by the two module sections
1 will produce a concrete column made up of a succession of rounded sections joined
by narrow necks between the rib flat tips 19.
[0019] The module sections 1 are provided with conventional tongues 27 and grooves 29 for
connection to adjoining modules 31, as illustrated in Fig. 4 where three modules 31
are shown interconnected. These tongue and groove joints of course prevent relative
lateral displacement of adjoining modules 31 of the formwork. As mentioned previously,
the modules 31 are laid in the same manner as bricks in a brick wall. They are rectangular
in shape with appropriate overall dimensions being 16 inches in height and 48 inches
in length; the thickness being variable as said before. As the formwork is being erected,
horizontal reinforcing bars 33 may be laid in the mold under formation in a manner
described below.
[0020] Figure 4 shows the two sections 1 of each module 31 to be interconnected by resilient
tie-rods 33, the assembly being made at the building site. The connection is best
illustrated in Fig. 5. The resilient tie-rods 33 have hooked ends lockingly engaged
into the hollowed ends of the tubular members 25 both at the top and at the bottom,
in the notches 21, 23. Each hooked end is formed of an inner part 35, flatly engaging
the bores of the hollowed ends of the tubular members 25, and an inclined terminal
part 37 in edge abutting engagement with the bores so as to prevent accidental withdrawal
of the rods 33 from the tubular members 25.
[0021] Resilient coupling rods 35 are used to prevent relative lifting of stacked modules
31 by interlocking engagement of adjoining pairs of tie-rods 33 at the bottom and
at the top of the stacked modules. For this purpose, and as shown in Fig. 6, one end
of each coupling rod 35 is bent at an acute angle to form a hook 37 adapted to firmly
wind around the lower tie-rod 33 while the other end also bends in the same direction
but far less sharply and then rises to form a smooth hooking elbow 39. In use, when
the tie-rods 33 have first been appropriately positioned in the tubular members 25,
the hook 37 is first wound around the lower tie-rod 33 and the hooked elbow 39 is
then snapped over the higher tie-rod 33, as illustrated in Fig. 5. Preferably, the
tie-rods 33 are bent slightly at their centers and toward one another to form nicks
41 adapted to receive the hooks 37 and the elbows 39, respectively. Reinforcement
bar supports may advantageously be provided, in the form of the support rods 43 fixed
at their centers to the centers of the coupling rods 35; the ends of the support rods
43 being bent in the form of triangular troughs 44 for the seating of reinforcement
bars 45.
[0022] In the embodiment of Figs. 7, 8, 9, 10 and 11, the inserts embedded in the ribs 13
are channel-shaped members 47 of which the ends project into the notches 21, 23 o
simply from the slopes 15, 17, of Fig. 3. The central web 49 of the members 47 is
formed with holes 51, preferably elongated slots, one such hole being in each of the
notches 21, 23, or immediately above the slopes 15, 17 of Fig. 3. In this case, the
tie-rods 53 have hooked ends that define an open recess engaged over the solid portions
of the webs 49 that circumscribe the holes 51. In Fig. 9, the open recess 55 is an
open circle. In the variant of Fig. 10, the open recess in the tie-rod 53ʹ is U-shaped
while in the tie-rod 53ʺ, it is a rabbet. In both tie-rods 53ʹ and 53ʺ, the terminal
portions are bent over the main portions to provide flexible arms 55, 55ʹ creating
a bias action to force the rods 53ʹ, 53ʺ, against the peripheral wall of the holes
51. The coupling rods 35 and support rods 43 are the same as in Fig. 5.
[0023] The foam plastic used in the molding of the module sections 1 is preferably expanded
cellular polystyrene made according to ASTM D1692-59T. It should of course be homogenous
throughout its mass and be free from any accumulation of unexpanded polystyrene particles
as well as of any foreign particles.
[0024] Vertical reinforcement bars (not shown) may of course be driven through the concrete
mix after pouring.
1. A formwork module section (1), made of foam plastic material, said section being
adapted to serve as one wall of a module of a formwork used in the molding of an insulated
concrete wall, said section comprising :
- a panel (3) having an outer face (5) and an inner face (7), an upper edge
(9) and a lower edge (11);
- spaced ribs (13) solid with said panel and projecting from said panel inner
face (7) between said edges (9, 11) each of said ribs having an upper and a lower
end (15, 17), and
- inserts (25) embedded, each in one of said ribs (13), said inserts being formed
with tie-rod receiving-and-locking apertures, said apertures being located at said
upper and lower ends of said ribs (13) and short of said panel upper (9) and lower
(11) edges.
2. A module section as claimed in claim 1, wherein said inserts are tubular members
(25) having hollowed ends opening at said ribs upper and lower ends; said hollowed
ends defining said tie-rod (33) receiving-and-locking apertures.
3. A module section as claimed in claim 1, wherein said inserts are channel-shaped
members (47) having ends projecting beyond said ribs (13) upper and lower ends ;
said channel-shaped members each having a central web (49) formed with holes (51)
through said member projecting ends ; said holes defining said tie-rod (53) receiving-and-locking
apertures.
4. A module section as claimed in claim 3, wherein said holes (51) are elongated slots.
5. A module section as claimed in anyone of claims 2 and 3, wherein said ribs (13)
each has a longitudinal flat tip (19) away from said inner face, wherein said ribs
have slopes inclined inwardly from said panel edges toward said flat tips and wherein
said ribs upper and lower ends (15, 17) are formed by notches (23) cut through said
slopes.
6. A formwork module comprising a pair of formwork module sections (1) as claimed
in claim 1, said sections being disposed in mirror position; said formwork module
further comprising :
- tie-rods (33) having hooked ends lockingly engaged into said insert apertures.
7. A formwork module comprising a pair of formwork module sections as claimed in
claim 2, said sections being disposed in mirror position; said formwork module further
comprising :
- tie rods (33) having hooked ends lockingly engaged into said hollowed ends
of said tubular members (25), said hooked ends being formed of an inner part (35),
flatly engaging the bores of said hollowed ends, and of an inclined terminal part
(37) in edge-butting engagement with the said bores to prevent withdrawal of said
tie-rods (33) from said tubular members.
8. A formwork module comprising a pair of formwork module sections (1) as claimed
in claim 3, said sections being disposed in mirror position; said formwork module
further comprising :
- tie rods (53) having hooked ends lockingly engaged into said holes, said hooked
ends defining open recesses engaged over portions of said channel-shaped members (47)
circumbscribing said holes.
9. A formwork for making an insulated concrete wall and comprising a pair of modules
(1) as claimed in claim 7, stacked one upon the other with adjoining tie-rods thereof
disposed one above the other, in pairs, said formwork further comprising :
- coupling rods (35) having hooked ends, said hooked ends interlocking with
the tie-rods (33) of said pairs of tie-rods for preventing vertical separation of
said formwork modules (31) as concrete is being poured into said formwork.
10. A formwork as claimed in claim 9, wherein said tie- rods (33) of a pair slightly
bend toward one another at the centers thereof to form nicks (41) and said hooked
ends (39) of said coupling rods engage into said nicks.
11. A formwork as claimed in claim 9, further comprising reinforcing bar supports
in the form of support rods (43) fixed to said coupling rods (35) between said tie-rods,
the ends of said support rods (43) being bent in the form of troughs (44) for the
lodging of reinforcement bars (45).
12. A formwork for making an insulated concrete wall and comprising a pair of modules
(1) as claimed in claim 8, stacked one upon the other with opening tie-rods thereof
disposed one above the other, in pairs, said formwork further comprising :
- coupling rods (35) having hooked ends, said hooked ends interlocking with
the tie-rods (33) of said pairs of tie-rods for preventing vertical separation of
said formwork modules (1) as concrete is being poured into said formwork.
13. A formwork as claimed in claim 12, wherein said tie-rods (33) of a pair slightly
bend toward one another at the centers thereof to form nicks (41) and said hooked
ends (39) of said coupling rods engage into said nicks.
14. A formwork as claimed in claim 12, further comprising reinforcing bar supports
in the form of support rods (43) fixed to said coupling rods (35) between said tie-rods,
the ends of said support rods (43) being bent in the form of troughs (44) for the
lodging of reinforcement bars (45).