CA1287748C - Concrete form and methods of manufacture thereof - Google Patents
Concrete form and methods of manufacture thereofInfo
- Publication number
- CA1287748C CA1287748C CA 526198 CA526198A CA1287748C CA 1287748 C CA1287748 C CA 1287748C CA 526198 CA526198 CA 526198 CA 526198 A CA526198 A CA 526198A CA 1287748 C CA1287748 C CA 1287748C
- Authority
- CA
- Canada
- Prior art keywords
- film
- concrete
- plastic
- concrete form
- inner member
- 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.)
- Expired
Links
Abstract
ABSTRACT
A lightweight, concrete form having an inner elongate cylindrical member with an internal opening having a cross section to provide the desired shape for a concrete column and a layer of film wrapped about the inner member and in tension to place the inner member in compression. In forming a nonround concrete column, the inner member is formed of a plastic foam and the tensioned, enclosing film may be either a stretch or a shrink film. The stretch film is wrapped about the inner member while under tension. The shrink film is loosely wrapped about the inner member and, thereafter, heat is applied to shrink the film. In both instances, the ends of the film are overlapped for self-adherence.
A lightweight, concrete form having an inner elongate cylindrical member with an internal opening having a cross section to provide the desired shape for a concrete column and a layer of film wrapped about the inner member and in tension to place the inner member in compression. In forming a nonround concrete column, the inner member is formed of a plastic foam and the tensioned, enclosing film may be either a stretch or a shrink film. The stretch film is wrapped about the inner member while under tension. The shrink film is loosely wrapped about the inner member and, thereafter, heat is applied to shrink the film. In both instances, the ends of the film are overlapped for self-adherence.
Description
'~ CONCREI'E POR~i AND METHODS
OF_MANUFACTURE THEREOF
Technical Fie_d This invention pertains to a lightweight, single-use concrete form for molding a concrete column. The concrete form can be constructed to form either a round or square column or other polygonally shaped column. The concrete form has an inner elongate cylindrical member having an internal opening of the desired cross-sectional shape for the concrete column and an external wrap of tensionea plastic film which places the inner cylindrical member in compression.
The methods embodied in manufacture of the concrete form include the forming of the inner elongate c~lindrical member and then wrapping a layer of plastic film around the inner elongate cylindrical member.
The film can be a stretch film which is tensioned and wrapped around the inner member and overlapped for self-adherence, or a shrink film which can be wrapped around the inner member and overlapped for self-adherence. Thereafter, heat is applied to the shrink film to achieve shrinking thereof and place the inner member in compression.
Background Art A well known concrete form for molding a round concrete column has a shell made up of several wound layers of paper material which are bonded to-gether. In forming columns of a shape other than round, such as a square column, it is conventional to assemble forms, such as wooden or steel forms, on the construction site.
i'7~
OF_MANUFACTURE THEREOF
Technical Fie_d This invention pertains to a lightweight, single-use concrete form for molding a concrete column. The concrete form can be constructed to form either a round or square column or other polygonally shaped column. The concrete form has an inner elongate cylindrical member having an internal opening of the desired cross-sectional shape for the concrete column and an external wrap of tensionea plastic film which places the inner cylindrical member in compression.
The methods embodied in manufacture of the concrete form include the forming of the inner elongate c~lindrical member and then wrapping a layer of plastic film around the inner elongate cylindrical member.
The film can be a stretch film which is tensioned and wrapped around the inner member and overlapped for self-adherence, or a shrink film which can be wrapped around the inner member and overlapped for self-adherence. Thereafter, heat is applied to the shrink film to achieve shrinking thereof and place the inner member in compression.
Background Art A well known concrete form for molding a round concrete column has a shell made up of several wound layers of paper material which are bonded to-gether. In forming columns of a shape other than round, such as a square column, it is conventional to assemble forms, such as wooden or steel forms, on the construction site.
i'7~
Included ln -the pa-ten-t ar-t are patents Nos.
2,873,503; 2,991,533; 3,301,926 and 3,350,049*, which d:iselose prefabricated concre-te forms Eor moldin~ a non-circular concrete column. These patents do no-t show a concrete Eorm having an inner elongate cylindrical member wi-th an internal opening of the desired cross section for the concrete column and a cylindrical exterior which is wrapped in a layer of tensioned plastic film to place the inner member in compression to provide adequate strength to resist the outward pressure of the poured concrete.
Disclosure of the Invention The invention broadly provides a lightweight concrete form comprising, in combination, an inner tubular member of sheet plastic material and an outer wrap of a layer of stretch plastic film wound thereon under tension to place the inner tubular member in compression, -the tension in the wrapped plastic film being sufficien-t to prevent the form from failing.
Additional features of the invention reside in the construction of the concrete form set forth in the preceding parac~raph wherein the outer wrap can ei-ther be a layer of stretch film wrapped about the inner member in tension and with the ends -thereof overlapped -to provide for self-adherence of the film or a layer of shrink film wrapped about the inner member and overlapped for self-adherence and which has had sufficient heat applied -thereto -to shrinlc the film and -tension the film to place the inner member in compression. The inner member can be constructed of a plastic foam, such as polyurethane or polyethylene foam, which is either initially molded or fabricated to the desired circular outer periphery * U.S. patent 2,873,503 DAVIS 2/1959 U.S. patent 2,991,533 REID ~T AL 7/1961 U.S. patent 3,301,926 REILAND 1/1967 U.S. patent 3,350,049 REILAND 10/1967 .
. ; ~' ~L2~3'7~48 and to have an internal opening oE t.he desired cross-sectiona:l shape for the column. The improved concrete form can also be used for pouring a round column wi-th a sheet of plastlc shaped into a cylinder and surrounded with a layer of tensioned film which exer-ts the necessary compression to strengthen the plastic sheet. An example of a plastic for the sheet is a high impact polystyrene.
The invention in one aspect provides a single-use concrete form for molding a concrete column, comprising, in combination, an inner elongate cylindrical member having, in cross section, a circular outer periphery and an internal opening to receive the poured concrete and which has the desired shape for the cross section of the concrete column and a layer of tensioned plastic film wrapped about the inner elongate cylindrical member to place the latter member in compression, the tension in the wrapped plastic film being sufficient to prevent the form from failing.
Fur-ther the invention provides a concrete forrn for a poured concrete column comprising, in combination, an inner member of foamed plastic having a circular periphery and an internal hollow shape to receive poured concrete and form the desired column cross section, and a single layer of stretch plastic film wound about -the inner member with the ends overlapped -Eor self-adherence and wound under tension to place said inner member in compression, the tension in the wrapped plastic film being sufficient to prevent the form from failing.
The invention still further provides a method of making a lightweight concrete form comprising, forming an inner member to a shape having a circular outer periphery and an internal opening of a cross section for the desired column shape and enclosing the inner member in a layer of tensioned plastic film with the ends thereof overlapped for self-adherence, the tension in the wrapped plastic film being sufficient to prevent the form from failing.
. ~ i .~ ~.
~ ~3~'48 More particularly the :invention provides a s:ingle-use concre-te form for moldlng a concrete column, comprislng, in combination, an inner elonga-te cylindrical member having, in cross section, a circular outer periphery and an internal opening to receive poured concrete and which has a desired shape for the cross section of the concrete column and a layer of thin tensioned plastic film wrapped circumferentially about the inner elongate cylindrical memher and place the cylindrical member in compression. The film comprises a film having an increased strength as a result of being stretched sufficient to prevent bursting of the cylindrical member by the expansion forces directed thereagainst by the poured concrete and to provide maintained support of the concrete as it sets.
In a preferred embodiment the film in a stretch film resiliently stretched at least about 75% of the film's initial length.
Brief Description of the Drawings Fig. 1 is a perspective fragmentary elevational view of -the concrete form with concrete therein;
Fig. 2 is a transverse sec-tional view, taken generally along the line 2 - 2 on an enlarged scale and with the outer wrap enlarged for clarity;
F'ig. 3 is a fragmentary view of the structure shown at the left in Fig. 2, again wi-th the outer wrap enlarged for clarity;
Fig. 4 is a transverse sec-tional view, taken generally along the line 4 - 4 in Fig. 1 and on an enlarged scale and wi-th the outer wrap further enlarged for clari-ty;
Fig. 5 is an enlarged view of a part of Fig. 4 at the left thereof, illustrating the detail of the s-tructure and with the outer wrap further enlarged for clarity;
FigO 6 is a view, similar to Fig. 2, of a second embodiment of the concrete form; and Fig. 7 is an enlarged view of the left-hand portion of Fig. 6 and with the outer wrap enlarged for clarity.
. , . .~.
.
2,873,503; 2,991,533; 3,301,926 and 3,350,049*, which d:iselose prefabricated concre-te forms Eor moldin~ a non-circular concrete column. These patents do no-t show a concrete Eorm having an inner elongate cylindrical member wi-th an internal opening of the desired cross section for the concrete column and a cylindrical exterior which is wrapped in a layer of tensioned plastic film to place the inner member in compression to provide adequate strength to resist the outward pressure of the poured concrete.
Disclosure of the Invention The invention broadly provides a lightweight concrete form comprising, in combination, an inner tubular member of sheet plastic material and an outer wrap of a layer of stretch plastic film wound thereon under tension to place the inner tubular member in compression, -the tension in the wrapped plastic film being sufficien-t to prevent the form from failing.
Additional features of the invention reside in the construction of the concrete form set forth in the preceding parac~raph wherein the outer wrap can ei-ther be a layer of stretch film wrapped about the inner member in tension and with the ends -thereof overlapped -to provide for self-adherence of the film or a layer of shrink film wrapped about the inner member and overlapped for self-adherence and which has had sufficient heat applied -thereto -to shrinlc the film and -tension the film to place the inner member in compression. The inner member can be constructed of a plastic foam, such as polyurethane or polyethylene foam, which is either initially molded or fabricated to the desired circular outer periphery * U.S. patent 2,873,503 DAVIS 2/1959 U.S. patent 2,991,533 REID ~T AL 7/1961 U.S. patent 3,301,926 REILAND 1/1967 U.S. patent 3,350,049 REILAND 10/1967 .
. ; ~' ~L2~3'7~48 and to have an internal opening oE t.he desired cross-sectiona:l shape for the column. The improved concrete form can also be used for pouring a round column wi-th a sheet of plastlc shaped into a cylinder and surrounded with a layer of tensioned film which exer-ts the necessary compression to strengthen the plastic sheet. An example of a plastic for the sheet is a high impact polystyrene.
The invention in one aspect provides a single-use concrete form for molding a concrete column, comprising, in combination, an inner elongate cylindrical member having, in cross section, a circular outer periphery and an internal opening to receive the poured concrete and which has the desired shape for the cross section of the concrete column and a layer of tensioned plastic film wrapped about the inner elongate cylindrical member to place the latter member in compression, the tension in the wrapped plastic film being sufficient to prevent the form from failing.
Fur-ther the invention provides a concrete forrn for a poured concrete column comprising, in combination, an inner member of foamed plastic having a circular periphery and an internal hollow shape to receive poured concrete and form the desired column cross section, and a single layer of stretch plastic film wound about -the inner member with the ends overlapped -Eor self-adherence and wound under tension to place said inner member in compression, the tension in the wrapped plastic film being sufficient to prevent the form from failing.
The invention still further provides a method of making a lightweight concrete form comprising, forming an inner member to a shape having a circular outer periphery and an internal opening of a cross section for the desired column shape and enclosing the inner member in a layer of tensioned plastic film with the ends thereof overlapped for self-adherence, the tension in the wrapped plastic film being sufficient to prevent the form from failing.
. ~ i .~ ~.
~ ~3~'48 More particularly the :invention provides a s:ingle-use concre-te form for moldlng a concrete column, comprislng, in combination, an inner elonga-te cylindrical member having, in cross section, a circular outer periphery and an internal opening to receive poured concrete and which has a desired shape for the cross section of the concrete column and a layer of thin tensioned plastic film wrapped circumferentially about the inner elongate cylindrical memher and place the cylindrical member in compression. The film comprises a film having an increased strength as a result of being stretched sufficient to prevent bursting of the cylindrical member by the expansion forces directed thereagainst by the poured concrete and to provide maintained support of the concrete as it sets.
In a preferred embodiment the film in a stretch film resiliently stretched at least about 75% of the film's initial length.
Brief Description of the Drawings Fig. 1 is a perspective fragmentary elevational view of -the concrete form with concrete therein;
Fig. 2 is a transverse sec-tional view, taken generally along the line 2 - 2 on an enlarged scale and with the outer wrap enlarged for clarity;
F'ig. 3 is a fragmentary view of the structure shown at the left in Fig. 2, again wi-th the outer wrap enlarged for clarity;
Fig. 4 is a transverse sec-tional view, taken generally along the line 4 - 4 in Fig. 1 and on an enlarged scale and wi-th the outer wrap further enlarged for clari-ty;
Fig. 5 is an enlarged view of a part of Fig. 4 at the left thereof, illustrating the detail of the s-tructure and with the outer wrap further enlarged for clarity;
FigO 6 is a view, similar to Fig. 2, of a second embodiment of the concrete form; and Fig. 7 is an enlarged view of the left-hand portion of Fig. 6 and with the outer wrap enlarged for clarity.
. , . .~.
.
3~77'~3 Best Modes ~or Carrying Out the Invention The concrete form is 6hown in place in~Fig. 1 and is indicated generally at 10. The ~tructure of the form is shown more particularly in Figs. 2-5. The form has an inner, elongate cylindrical member 15 formed of a lightweight plastic foam, such as a polyurethane or a polyethylene foam having a circular outer periphery 16 and an internal opening 17 which is of a cross-sectional shape to provide the desired cross-sectional shape for the concrete column. The plastic foam has sufficient strength in c~mpression to resist crushing as a result of pressure exerted by concrete poured into the form, but does not have sufficien~ strength to prevent bursting as a result of forces generated by the poured concrete.
The inner elongate cylindrical member lS can either be molded to the cross-sectional shape shown in Fig. 2 or fabricated from a block of plastic ~oam to the desired internal and external configurations.
The plastic foam is placed in compression to prevent bursting by a layer of plastic film 20 which is wrapped about the ~oam and with adjacent ends 20a and 20b of the film overlapped for self-adherence which is characteristic of the film. The film is tensioned around the inner member 15. Examples of suitable films having the required tensile strength and which can be tensioned to place the inner membex 15 under compression and which provides for self-adherence by the overlapped ends 20a and 20b arestretch and shrink films.
When using a stretch film, the inner member 15 is placed on a mandrel of a stretch wrapping machine, 3'7~48 such as a Lan-wrapperTM machine of Lantech Corporation, and the machine is operated -to place a single layer of the Eilm about the inner member and with an adequate overlap oE the ends to provide the self-adherence which is inherent in the stretch film. An example of such a stretch Eilm is a coextruded linear low-density polyethylene film having a thickness in the range of approximately 60 - 1.6 mils. A commercially available material is MOBILRAP M film, marketed by Mobil Chemical. This film can be wrapped about the inner member with a tension which produces up to 250% stretch. However a stretch in the range of 75% to 150% is quite adequate to increase the strength of the film and impart resilient compression on the inner member.
~ lternatively, the tensioned film wrapped about the inner member 15 can be a shrink film of a commercially available type of an approximate thickness oE 6 mils and which is loosely wrapped around the inner member with the ends overlapped for self-adherence. The structure is then exposed to heat at a relatively high temperature for a short period of time to shrink the shrink film and place the inner member under compression.
Both the stretch and shrink films have adequate tensile strength to place the inner member in compression to resist the pressure exerted by concrete poured into the concrete form.
The concrete column i5 seen in Figs, 1 and 2 wherein the concrete 25 forms a square column, as defined by a square shape of the internal opening 17 in the inner member 15 and has reinforcing bars 26 extending lengthwise thereof and imbedded in the concrete.
A single layer of the tensioned film 20 is normally adequa-te for a concrete form for pouring a column of normal height. If an unusually tall or large 3~ 48 diameter column is to be poured, the concrete form can be constructed with multi-layers of tensioned film.
This structure for the lower portion of a tall column is shown in Figs. 4 and 5 wherein a second layer 30 of tensioned film is wrapped about ~he previously~
described layer 20. The layer 30 has overlapped ends 30a and 30b for self-adherence of this outer layer.
In either the stretch film or shrink film embodiments, the first layer 20 is applied to the inner member 15 and placed under tension either by initial winding thereof or by heat applied to the shrink film and, thereafter, the outer layer 30 is applied and similarly treated to be placed under tension.
The cross-sectional shape of the column is shown as being square, although it will be obvious that the column can be round Dr of some polygonal shape other than square, with a suitable shaping of the in-ternal opening of ~he inner member 15. The thickness of the layers 20 and 30 is greatly exaggerated in the drawings for clarity. It will be evident from the dimensions given for the thickness of the film of the layers that the actual thickness thereof is almost imperceptible when considering a concrete form of a size to form the column.
The concrete form is extremely light and easy to handle, since it has an inner member of~lightweight plastic foam which, in one embodiment, could have a weigh~ of approximately 2 pounds per cubic ~ootO The film which places the foam in compression has very little weight.
After the concrete has set, a vertical cut may be made along the length of the concrete form for easy separation thereof for removal from the concrete column ~ ~3'~ 8 Another embodiment of the invention is shown in Figs. 6 and ~ wherein the concrete form is con-structed of components -for pouring a round column only7 s In ~his embodiment, a round concrete column has concrete 40 with reinforcing rods 41~ The concreta form has an inner elongate cylindr,ical member 50 formed from a sheet of plastic material which is bonded along adjacent edges at a butt joint 51. A
layer 55 of tensioned fiLm surrounds the inner member 50, with the ends of the film overlapped as shown at 56. The film layer 55 can be either a stretch film or a shrink film and tensioned as described in connection with the film layer 20 in the embodiment of Fig. 2. Th~
butt seal 51 between adjacent edges of the sheet 50 is only for the purpose of resisting compression exerted as the film layer 55 is tensioned a~out the inner mem-ber 50. An example of a suitable member for forming - the inner elongate cylindrical member 50 is a one-inch thick, high impact polystyrene sheet material.
It is characteristic of polyurethane foam to have a skin which will result in a satisfactory surface for the concrete column. In order to achieve a smooth column surface when using polystyrene foam, a liner (not shown) can be inserted within the internal opening of the inner elongate cylindrical member 15~and this can also be removed after the concrete has set.
The methods of making a lightweight, single-use concrete form are believed evident from the fore-going description. In summary, the methods have thecommon steps of forming an inner elongate cylindrical member with an internal opening of a desired cross sectional shape for the cross-sectional shape of a ~ ~3~ 4~
_g concrete coiumn to be formed, followed by wrapping of a sheet o~ plastic film about the inner elongate cylin-drical member wi~h overlapping of the ends of the film to achieve self-adherence of the film. In one embodi-S ment of the method, ~he film is a stretch film and iswrapped about the inner elonyate cylindrical member under tension to resultingly place the inner member in compression. In another embod~ment of the method, the film is a shrink film which is loosely placed about the inner member and the succeeding step involves the application of high heat for a short time period to the shrink film to shrink the film and place it in tension to place the inner member in compression.
The inner elongate cylindrical member lS can either be molded to the cross-sectional shape shown in Fig. 2 or fabricated from a block of plastic ~oam to the desired internal and external configurations.
The plastic foam is placed in compression to prevent bursting by a layer of plastic film 20 which is wrapped about the ~oam and with adjacent ends 20a and 20b of the film overlapped for self-adherence which is characteristic of the film. The film is tensioned around the inner member 15. Examples of suitable films having the required tensile strength and which can be tensioned to place the inner membex 15 under compression and which provides for self-adherence by the overlapped ends 20a and 20b arestretch and shrink films.
When using a stretch film, the inner member 15 is placed on a mandrel of a stretch wrapping machine, 3'7~48 such as a Lan-wrapperTM machine of Lantech Corporation, and the machine is operated -to place a single layer of the Eilm about the inner member and with an adequate overlap oE the ends to provide the self-adherence which is inherent in the stretch film. An example of such a stretch Eilm is a coextruded linear low-density polyethylene film having a thickness in the range of approximately 60 - 1.6 mils. A commercially available material is MOBILRAP M film, marketed by Mobil Chemical. This film can be wrapped about the inner member with a tension which produces up to 250% stretch. However a stretch in the range of 75% to 150% is quite adequate to increase the strength of the film and impart resilient compression on the inner member.
~ lternatively, the tensioned film wrapped about the inner member 15 can be a shrink film of a commercially available type of an approximate thickness oE 6 mils and which is loosely wrapped around the inner member with the ends overlapped for self-adherence. The structure is then exposed to heat at a relatively high temperature for a short period of time to shrink the shrink film and place the inner member under compression.
Both the stretch and shrink films have adequate tensile strength to place the inner member in compression to resist the pressure exerted by concrete poured into the concrete form.
The concrete column i5 seen in Figs, 1 and 2 wherein the concrete 25 forms a square column, as defined by a square shape of the internal opening 17 in the inner member 15 and has reinforcing bars 26 extending lengthwise thereof and imbedded in the concrete.
A single layer of the tensioned film 20 is normally adequa-te for a concrete form for pouring a column of normal height. If an unusually tall or large 3~ 48 diameter column is to be poured, the concrete form can be constructed with multi-layers of tensioned film.
This structure for the lower portion of a tall column is shown in Figs. 4 and 5 wherein a second layer 30 of tensioned film is wrapped about ~he previously~
described layer 20. The layer 30 has overlapped ends 30a and 30b for self-adherence of this outer layer.
In either the stretch film or shrink film embodiments, the first layer 20 is applied to the inner member 15 and placed under tension either by initial winding thereof or by heat applied to the shrink film and, thereafter, the outer layer 30 is applied and similarly treated to be placed under tension.
The cross-sectional shape of the column is shown as being square, although it will be obvious that the column can be round Dr of some polygonal shape other than square, with a suitable shaping of the in-ternal opening of ~he inner member 15. The thickness of the layers 20 and 30 is greatly exaggerated in the drawings for clarity. It will be evident from the dimensions given for the thickness of the film of the layers that the actual thickness thereof is almost imperceptible when considering a concrete form of a size to form the column.
The concrete form is extremely light and easy to handle, since it has an inner member of~lightweight plastic foam which, in one embodiment, could have a weigh~ of approximately 2 pounds per cubic ~ootO The film which places the foam in compression has very little weight.
After the concrete has set, a vertical cut may be made along the length of the concrete form for easy separation thereof for removal from the concrete column ~ ~3'~ 8 Another embodiment of the invention is shown in Figs. 6 and ~ wherein the concrete form is con-structed of components -for pouring a round column only7 s In ~his embodiment, a round concrete column has concrete 40 with reinforcing rods 41~ The concreta form has an inner elongate cylindr,ical member 50 formed from a sheet of plastic material which is bonded along adjacent edges at a butt joint 51. A
layer 55 of tensioned fiLm surrounds the inner member 50, with the ends of the film overlapped as shown at 56. The film layer 55 can be either a stretch film or a shrink film and tensioned as described in connection with the film layer 20 in the embodiment of Fig. 2. Th~
butt seal 51 between adjacent edges of the sheet 50 is only for the purpose of resisting compression exerted as the film layer 55 is tensioned a~out the inner mem-ber 50. An example of a suitable member for forming - the inner elongate cylindrical member 50 is a one-inch thick, high impact polystyrene sheet material.
It is characteristic of polyurethane foam to have a skin which will result in a satisfactory surface for the concrete column. In order to achieve a smooth column surface when using polystyrene foam, a liner (not shown) can be inserted within the internal opening of the inner elongate cylindrical member 15~and this can also be removed after the concrete has set.
The methods of making a lightweight, single-use concrete form are believed evident from the fore-going description. In summary, the methods have thecommon steps of forming an inner elongate cylindrical member with an internal opening of a desired cross sectional shape for the cross-sectional shape of a ~ ~3~ 4~
_g concrete coiumn to be formed, followed by wrapping of a sheet o~ plastic film about the inner elongate cylin-drical member wi~h overlapping of the ends of the film to achieve self-adherence of the film. In one embodi-S ment of the method, ~he film is a stretch film and iswrapped about the inner elonyate cylindrical member under tension to resultingly place the inner member in compression. In another embod~ment of the method, the film is a shrink film which is loosely placed about the inner member and the succeeding step involves the application of high heat for a short time period to the shrink film to shrink the film and place it in tension to place the inner member in compression.
Claims (27)
1. A single-use concrete form for molding a concrete column, comprising, in combination, an inner elongate cylindrical member having, in cross section, a circular outer periphery and an internal opening to receive the poured concrete and which has the desired shape for the cross section of the concrete column, and a layer of tensioned plastic film wrapped about the inner elongate cylindrical member to place the latter member in compression, the tension in said wrapped plastic film being sufficient to prevent the form from failing.
2. A concrete form as defined in claim 1 wherein said plastic film is a stretch film wound onto the inner member under tension and with the ends overlapped for self-adherence.
3. A concrete form as defined in claim 2 wherein said plastic film is a coextruded linear low-density polyethylene.
4. A concrete form as defined in claim 1 wherein said inner member is formed of plastic foam.
5. A concrete form as defined in claim 4 wherein said plastic foam is a polyurethane.
6. A concrete form as defined in claim 4 wherein said plastic foam is a polystyrene.
7. A concrete form as defined in claim 1 wherein said inner member is formed of a sheet of plastic material.
8. A concrete form as defined in claim 7 wherein said plastic material is high impact polystyrene.
9. A concrete form as defined in claim 1 wherein said plastic film is a shrink film.
10. A concrete form as defined in claim 9 wherein said shrink film is wound onto said inner member and thereafter heated to cause shrinking thereof with resulting compression of the inner member.
11. A concrete form as defined in claim 1 wherein the lower part thereof has a second layer of tensioned plastic film on said first-mentioned layer of tensioned plastic film for increased strength.
12. A lightweight concrete form comprising, in combination, an inner tubular member of sheet plastic material, and an outer wrap of a layer of stretch plastic film wound thereon under tension to place said inner tubular member in compression, the tension in said wrapped plastic film being sufficient to prevent the form from failing.
13. A concrete form for a poured concrete column comprising, in combination, an inner member of foamed plastic having a circular periphery and an internal hollow shape to receive poured concrete and form the desired column cross section, and a single layer of stretch plastic film wound about the inner member with the ends overlapped for self-adherence and wound under tension to place said inner member in compression, the tension in said wrapped plastic film being sufficient to prevent the form from failing.
14. A concrete form as defined in claim 13 wherein said internal hollow shape is square in cross section to form a square concrete column.
15. The method of making a lightweight concrete form comprising, forming an inner member to a shape having a circular outer periphery and an internal opening of a cross section for the desired column shape and enclosing said inner member in a layer of tensioned plastic film with the ends thereof overlapped for self-adherence, the tension in said wrapped plastic film being sufficient to prevent the form from failing.
16. The method of claim 15 wherein said plastic film is a stretch film, and applying tension to said stretch film while wrapping the film around the inner member.
17. The method of claim 15 wherein said plastic film is a shrink film, said shrink film being heated after being placed on said inner member to shrink and tension the shrink film.
18. A concrete form as defined in claim 1 wherein the tensioned plastic film is a layer of thin plastic stretch film resiliently stretched at least about 75% of the film's initial length about the inner elongate cylindrical member.
19. A concrete form as defined in claim 18 wherein said thin plastic stretch film has ends overlapped for self-adherence.
20. A concrete form as defined in claim 18 wherein said inner member is formed of plastic foam.
21. A concrete form as defined in claim 20 wherein said plastic foam is a polyurethane.
22. A concrete form as defined in claim 20 wherein said plastic foam is a polystyrene.
23. A concrete form as defined in claim 19 wherein said inner member is formed of a sheet of plastic material.
24. A concrete form as defined in claim 23 wherein said plastic material is high impact polystyrene.
25. A concrete form as defined in claim 19 wherein the form has upper and lower ends, the lower end thereof has a second layer of thin plastic stretch film stretched onto said first-mentioned layer of thin plastic stretch film for increased strength.
26. A lightweight concrete form comprising, in combination, an inner tubular member of sheet plastic material, and an outer wrap of a layer of thin plastic stretch film resiliently stretched at least about 75% of the film's initial length around the inner tubular member to place said inner tubular member in compression.
27. A single-use concrete form for molding a concrete column, comprising, in combination, an inner elongate cylindrical member having, in cross section, a circular outer periphery and an internal opening to receive poured concrete and which has a desired shape for the cross section of the concrete column, and a layer of thin tensioned plastic film wrapped circumferentially about the inner elongate cylindrical member and place said cylindrical member in compression, said film comprising a film having an increased strength as a result of being stretched sufficient to prevent bursting of the cylindrical member by the expansion forces directed thereagainst by the poured concrete and to provide maintained support of the concrete as it sets.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US07/110,224 US4767095A (en) | 1986-12-23 | 1987-10-19 | Concrete column form |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US86794786A | 1986-05-29 | 1986-05-29 | |
| US867,947 | 1992-04-13 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1287748C true CA1287748C (en) | 1991-08-20 |
Family
ID=25350771
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 526198 Expired CA1287748C (en) | 1986-05-29 | 1986-12-23 | Concrete form and methods of manufacture thereof |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1287748C (en) |
-
1986
- 1986-12-23 CA CA 526198 patent/CA1287748C/en not_active Expired
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4767095A (en) | Concrete column form | |
| US5658519A (en) | Reinforced plastic piling and method and apparatus for making same | |
| US5599599A (en) | Fiber reinforced plastic ("FRP")-concrete composite structural members | |
| US3301926A (en) | Method of fabricating a self-braced concrete form | |
| US2677165A (en) | Concrete form and method of molding concrete columns therewith | |
| US5814386A (en) | Composite shell formed as a body of rotation, and method and mandrel for making same | |
| US4903446A (en) | Prestressed plastic foam structural member | |
| US3350049A (en) | Concrete forms | |
| AU2940789A (en) | Storage tanks with fabricated support ribs | |
| DE2932375A1 (en) | METHOD FOR PRODUCING A PACKAGING CONTAINER FROM PLASTIC | |
| US3728749A (en) | Tire float and method for forming same | |
| WO1993014287A1 (en) | Form for casting building elements | |
| US5245813A (en) | Structural beam | |
| CA1287748C (en) | Concrete form and methods of manufacture thereof | |
| CA2020159A1 (en) | Tendons for prestressed concrete structures and method of using and process for making such tendons | |
| JPH03251435A (en) | Frp pipe and its manufacture | |
| US4079170A (en) | Wax saturated expanded polystyrene and method of manufacture | |
| JPH04197740A (en) | Shaft-like member made by combining heat-expandable resin and carbon fiber and manufacture thereof | |
| US11591810B2 (en) | Reusable and adjustable-size form for repair and reinforcement of structures | |
| JPH09300488A (en) | Double paper tube and its preparation | |
| JPH06129058A (en) | Coupling for rod | |
| DE3311734A1 (en) | Process for manufacturing a surfboard | |
| US5935704A (en) | Incremental filament wound pole | |
| US20050247852A1 (en) | Disposable formwork for columns having a circular section | |
| JP3719795B2 (en) | Composite joint pile and manufacturing method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed |