CA2030080A1 - Void form - Google Patents
Void formInfo
- Publication number
- CA2030080A1 CA2030080A1 CA 2030080 CA2030080A CA2030080A1 CA 2030080 A1 CA2030080 A1 CA 2030080A1 CA 2030080 CA2030080 CA 2030080 CA 2030080 A CA2030080 A CA 2030080A CA 2030080 A1 CA2030080 A1 CA 2030080A1
- Authority
- CA
- Canada
- Prior art keywords
- projections
- void form
- void
- rectangular
- pieces
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 239000011800 void material Substances 0.000 title claims abstract description 40
- 239000004794 expanded polystyrene Substances 0.000 claims description 8
- 230000013011 mating Effects 0.000 claims description 3
- 238000000034 method Methods 0.000 claims 1
- 238000000465 moulding Methods 0.000 claims 1
- 238000010276 construction Methods 0.000 abstract description 11
- 239000000463 material Substances 0.000 description 4
- 238000009415 formwork Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
Landscapes
- Investigation Of Foundation Soil And Reinforcement Of Foundation Soil By Compacting Or Drainage (AREA)
Abstract
ABSTRACT
A unique void form for use under grade beams in construction sites is disclosed. The void form has downwardly extending projections which run across the width of the void form at 90° to the longitudinal axis. The projections support the void form on the subsoil and provide additional space for the subsoil to heave as a result of frost or other temperature changes. The top of the void form has a flat surface and is adapted to support a poured concrete grade beam. The form is left in the ground after construction is complete.
A unique void form for use under grade beams in construction sites is disclosed. The void form has downwardly extending projections which run across the width of the void form at 90° to the longitudinal axis. The projections support the void form on the subsoil and provide additional space for the subsoil to heave as a result of frost or other temperature changes. The top of the void form has a flat surface and is adapted to support a poured concrete grade beam. The form is left in the ground after construction is complete.
Description
3 ~ 0 8~
This invention relates to grade beam construction and in particular relates to void forms for use under grade beams.
In certain cold regions of Canada where frost entry into the subsoil is substantial, cer~ain municipalities have building codes which are designed to ensure ~hat new buildings constructed will not heave or crack.
In particular, constructions such as attached garages where no basement is required, employ a construction where pilings are poured down in the earth and a grade beam (or foundation) is poured on top and supported by the pilings. Under that portion of the concrete grade beam, which is not supported by ~he pilinys, a void form made of some easily compressible material is used. This permits the subsoil below the grade beam in the void space to heave and move as a result o frost, without damaging the grade beam.
Rather than simply leaving an air space and pouring the concrete grade beam form thereover, it has been found that by using a compressible material which can be left in the ground, the construction is less expensive.
In modern construction the compressible material is laid along the ground between the pilings and the concrete is poured thereGn to form the form. Obviously, the compressible material must be strong enough to support the weight of the uncured poure~
concrete. As well, it must be allowed to compress, thereby absorbing movement when the ground heaves during the winter, spring and fall and thus reduce the strain on the grade beam.
, ' , ' ' ' ' ' 2~ 8~
Presently in the art, slabs or rectangular blocks of expanded polystyrene are used as a void form. These have a support strength of 8 pounds per square inch which is more than is necessary to support wet concrete, but which has sufficient compressibility to be a recommended void form.
Others have attempted to reduce the support strength of the expanded polystyrene by making a less dense form of the product which is slightly less expensive to construct. This less dense form of expanded polystyrene typically has an approximate support strength of 7 pounds per square inch. The problem with both types of void forms are that they are bulky, thus the volume required for transportation is expensive.
It is an object of the present invention to produce a void form out of expanded polystyrene which takes up approximately 2/3 the space during transportation and yet which has sufficient strength to support poured concrete and sufficient compressibility to allow for heaving of the subsoil without damage to the grade beam or the concrete structure.
It is a urther object of the present invention to provide a void form which has increased empty air space, which allows for more movement of the subsoil.
Therefore this invention seeks to provide a void form for use under a grade beam comprising a rectangular one-piece molded expanded polystyrene slab having a flat upper surface and a plurality of projections extending downward from a lower surface;
said projections running across the width of said lower surEace at 90 to the longitudinal axis of said slab.
' : -ll 2~3~8~
To make the invention, a normal 8 pounds per square inch support strength rectangular block of expanded polystyrene is used. Thereafter, by using hot wires, two void forms having projections extending downwardly from the lower surface, when in use, are created. The resultant 2 void forms have a perfect mating relationship with one another and thus two void for~ns take 2/3 of the space during transportation as the presently used solid rectangular blocks. It has also been found that these void forms have more than sufEicient strength to support wet poured concrete;
up to a grade beam depth of 4 feet.
Furthermore, it has also been found that by having empty air spaces between the projections above the subsoil, less frost damage occurs and the void form works more efficiently to protect the concrete structure. Recent tests have shown that the present invention developes approximately 1/2 the stress of a prior art rectangular slab at 50% strain.
The invention is described in greater detail in conjunction with the following drawings wherein:
Figure l is a longitudinal cross-sectional view through a typical construction using a void form;
Figure 2 is a cross-sectional end view of the same construction;
Figure 3 is a side view of the typical void form of the present invention;
Figures ~ and 5 are side views of alternative configurations of the void form of the present inv~ntion; and Figure 6 is a partial side view o two void Eorms of the .
';~ 2~a8~
present invention in mating relationship, ready for transport.
In Figure l one sees a longitudinal cross-sectional view of a typical construction using a void form~ The void form ~l i5 placed on the subsoil 2. Pilings 3 are placed in the ground and concrete poured down to an area below the frost line. Once the void form is in place a concrete grade beam 4 is poured from piling to piling and supported in the middle by the void form l.
In Figure 2 one sees, in a cross-sectional end view, the void form l supporting the poured concrete 4. Once the concrete 4 is poured -there is no need to use the void form. However, for ease of construction, it is recommended that the void form be left in the ground.
In Figures 2 and 3, the void form shown has a flat upper surface 5 and a number of projections 6 which extend downwardly from the under-surface 7. The bottoms ~, of projections 6, rest on the subsoil. The air spaces 9 created between the projections ` 6 permit the subsoil to expand and contract more easily. The projections 6 extend length-wise along the bottom of the grade beam its entire length and are generally parallel to the longitudinal axis of the grade beam.
Figures 4 and 5 show partial side views of alternative forms of the void beam, having in one case triangular projections 6a and in another case, rounded projections 6b, which have rounded ends.
Figure 6 shows in a partial side view two void forms after having been cut, mated together and ready for transport.
One notes that by cutting through a single rectangular block one : . .
"~ , obtains two blocks oE substantially symmetrical configuration having each a top surface 5 and projections 6. It should be noted that other configurations could bs created other than those shown in Figures 4 and 5 without departing from the spirit of the invention.
. . ~
This invention relates to grade beam construction and in particular relates to void forms for use under grade beams.
In certain cold regions of Canada where frost entry into the subsoil is substantial, cer~ain municipalities have building codes which are designed to ensure ~hat new buildings constructed will not heave or crack.
In particular, constructions such as attached garages where no basement is required, employ a construction where pilings are poured down in the earth and a grade beam (or foundation) is poured on top and supported by the pilings. Under that portion of the concrete grade beam, which is not supported by ~he pilinys, a void form made of some easily compressible material is used. This permits the subsoil below the grade beam in the void space to heave and move as a result o frost, without damaging the grade beam.
Rather than simply leaving an air space and pouring the concrete grade beam form thereover, it has been found that by using a compressible material which can be left in the ground, the construction is less expensive.
In modern construction the compressible material is laid along the ground between the pilings and the concrete is poured thereGn to form the form. Obviously, the compressible material must be strong enough to support the weight of the uncured poure~
concrete. As well, it must be allowed to compress, thereby absorbing movement when the ground heaves during the winter, spring and fall and thus reduce the strain on the grade beam.
, ' , ' ' ' ' ' 2~ 8~
Presently in the art, slabs or rectangular blocks of expanded polystyrene are used as a void form. These have a support strength of 8 pounds per square inch which is more than is necessary to support wet concrete, but which has sufficient compressibility to be a recommended void form.
Others have attempted to reduce the support strength of the expanded polystyrene by making a less dense form of the product which is slightly less expensive to construct. This less dense form of expanded polystyrene typically has an approximate support strength of 7 pounds per square inch. The problem with both types of void forms are that they are bulky, thus the volume required for transportation is expensive.
It is an object of the present invention to produce a void form out of expanded polystyrene which takes up approximately 2/3 the space during transportation and yet which has sufficient strength to support poured concrete and sufficient compressibility to allow for heaving of the subsoil without damage to the grade beam or the concrete structure.
It is a urther object of the present invention to provide a void form which has increased empty air space, which allows for more movement of the subsoil.
Therefore this invention seeks to provide a void form for use under a grade beam comprising a rectangular one-piece molded expanded polystyrene slab having a flat upper surface and a plurality of projections extending downward from a lower surface;
said projections running across the width of said lower surEace at 90 to the longitudinal axis of said slab.
' : -ll 2~3~8~
To make the invention, a normal 8 pounds per square inch support strength rectangular block of expanded polystyrene is used. Thereafter, by using hot wires, two void forms having projections extending downwardly from the lower surface, when in use, are created. The resultant 2 void forms have a perfect mating relationship with one another and thus two void for~ns take 2/3 of the space during transportation as the presently used solid rectangular blocks. It has also been found that these void forms have more than sufEicient strength to support wet poured concrete;
up to a grade beam depth of 4 feet.
Furthermore, it has also been found that by having empty air spaces between the projections above the subsoil, less frost damage occurs and the void form works more efficiently to protect the concrete structure. Recent tests have shown that the present invention developes approximately 1/2 the stress of a prior art rectangular slab at 50% strain.
The invention is described in greater detail in conjunction with the following drawings wherein:
Figure l is a longitudinal cross-sectional view through a typical construction using a void form;
Figure 2 is a cross-sectional end view of the same construction;
Figure 3 is a side view of the typical void form of the present invention;
Figures ~ and 5 are side views of alternative configurations of the void form of the present inv~ntion; and Figure 6 is a partial side view o two void Eorms of the .
';~ 2~a8~
present invention in mating relationship, ready for transport.
In Figure l one sees a longitudinal cross-sectional view of a typical construction using a void form~ The void form ~l i5 placed on the subsoil 2. Pilings 3 are placed in the ground and concrete poured down to an area below the frost line. Once the void form is in place a concrete grade beam 4 is poured from piling to piling and supported in the middle by the void form l.
In Figure 2 one sees, in a cross-sectional end view, the void form l supporting the poured concrete 4. Once the concrete 4 is poured -there is no need to use the void form. However, for ease of construction, it is recommended that the void form be left in the ground.
In Figures 2 and 3, the void form shown has a flat upper surface 5 and a number of projections 6 which extend downwardly from the under-surface 7. The bottoms ~, of projections 6, rest on the subsoil. The air spaces 9 created between the projections ` 6 permit the subsoil to expand and contract more easily. The projections 6 extend length-wise along the bottom of the grade beam its entire length and are generally parallel to the longitudinal axis of the grade beam.
Figures 4 and 5 show partial side views of alternative forms of the void beam, having in one case triangular projections 6a and in another case, rounded projections 6b, which have rounded ends.
Figure 6 shows in a partial side view two void forms after having been cut, mated together and ready for transport.
One notes that by cutting through a single rectangular block one : . .
"~ , obtains two blocks oE substantially symmetrical configuration having each a top surface 5 and projections 6. It should be noted that other configurations could bs created other than those shown in Figures 4 and 5 without departing from the spirit of the invention.
. . ~
Claims (6)
1. A void form for use under a grade beam comprising a rectangular one-piece molded expanded polystyrene slab having a flat upper surface and a plurality of projections extending downward from a lower surface; said projections extending across the width of said lower surface at 90° to the longitudinal axis of said slab.
2. A void form as claimed in claim 1 wherein said projections are rectangular in cross-section.
3. A void form as claimed in claim 1 wherein said projections are triangular in cross-section.
4. A void form as claimed in claim l wherein said projections are generally rectangular with rounded ends in cross-section.
5. A void form as claimed in claim l having a support strength of at least 4 pounds per square inch.
6. A method of constructing and transporting a pair of void forms as claimed in claim l comprising the steps of:
(1) molding a rectangular block of expanded polystyrene;
(2) cutting said block with hot wires into two pieces, each of said pieces having downwardly extending projections and each of said pieces being the mirror image of the other; and (3) placing said pieces together in mating relationship for transport.
(1) molding a rectangular block of expanded polystyrene;
(2) cutting said block with hot wires into two pieces, each of said pieces having downwardly extending projections and each of said pieces being the mirror image of the other; and (3) placing said pieces together in mating relationship for transport.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2030080 CA2030080A1 (en) | 1990-11-15 | 1990-11-15 | Void form |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2030080 CA2030080A1 (en) | 1990-11-15 | 1990-11-15 | Void form |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2030080A1 true CA2030080A1 (en) | 1992-05-16 |
Family
ID=4146444
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2030080 Abandoned CA2030080A1 (en) | 1990-11-15 | 1990-11-15 | Void form |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2030080A1 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AU2007203032B2 (en) * | 2006-06-30 | 2011-01-27 | Superslab Tech Pty Ltd | Void forming and suspension system for a structural concrete slab |
| US8472656B2 (en) | 2007-04-04 | 2013-06-25 | Funai Electric Advanced Applied Technology Research Institute Inc. | Microphone unit , voice input device, and method of manufacturing microphone unit |
| AU2011201876B2 (en) * | 2006-06-30 | 2014-07-31 | Superslab Tech Pty Ltd | Apparatus for creating a void beneath a suspended structural concrete slab |
| US12163345B2 (en) | 2020-04-14 | 2024-12-10 | Voidform Products, Llc | Modular void form structure |
-
1990
- 1990-11-15 CA CA 2030080 patent/CA2030080A1/en not_active Abandoned
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AU2007203032B2 (en) * | 2006-06-30 | 2011-01-27 | Superslab Tech Pty Ltd | Void forming and suspension system for a structural concrete slab |
| AU2011201876B2 (en) * | 2006-06-30 | 2014-07-31 | Superslab Tech Pty Ltd | Apparatus for creating a void beneath a suspended structural concrete slab |
| US8472656B2 (en) | 2007-04-04 | 2013-06-25 | Funai Electric Advanced Applied Technology Research Institute Inc. | Microphone unit , voice input device, and method of manufacturing microphone unit |
| US12163345B2 (en) | 2020-04-14 | 2024-12-10 | Voidform Products, Llc | Modular void form structure |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Dead |