US20090113829A1

US20090113829A1 - Three dimensional building element

Info

Publication number: US20090113829A1
Application number: US12/118,741
Authority: US
Inventors: Franz X. Meier
Original assignee: Meier Franz X
Current assignee: Titan Atlas Manufacturing
Priority date: 2007-05-14
Filing date: 2008-05-11
Publication date: 2009-05-07
Also published as: US8347191B1

Abstract

Disclosed is a three dimensional building element having outer shells formed from cementitious compositions having different densities. The outer shell forming the exterior portion of the building element has a density greater than the interior shell to provide structure strength. The interior shell is formed from a lower density cementitious compound to provide an interior wall portion of a structure with a smooth finished appearance. The lower density of the interior cementitious compound enables the interior shell to obtain a smooth finished appearance without the need to apply various secondary coatings such as plaster or drywall.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. Provisional Patent Application Ser. No. 60/917,648 filed May 12, 2007, the contents of which are hereby incorporated in their entirety.

TECHNICAL FIELD

The present system relates to a three dimensional building element and to a method of forming the same and in greater detail the system includes a three dimensional building element having outer cementitious shells having different densities such that the interior outer shell has a lower density than the exterior outer shell of the building element.

BACKGROUND

Structures or buildings have commonly been formed from various prefabricated elements. For example, one common prefabricated building element comprises a three dimensional building elements having cementitious shells to form portions or all of a completed structure. Such building elements have the advantage of being both structurally very sound and resistant to both moisture and fire.
An example of such a building element is one formed from a three-dimensional grid having an insulating body housed within the grid. The insulating body both lightens the building element while providing insulation against both sound and the elements. The building element is further finished with an application of concrete commonly referred to as shotcrete on both sides of the element to provide structural support.
One specific example of a three dimensional building element commonly used in assembling a structure includes a panel having two parallel welded wire grid mats and associated web wires holding the wire grid mats at a distance from one another. An insulating body is arranged between the wire grid mats. The web wires extend through and support the insulating body between the wire grid mats. To improve the adhesion of the concrete to the insulating body, the insulating body may include roughened surfaces. The resulting panels are finished with an application of shotcrete to both sides and can be used as structural elements.
A further example, includes a three dimensional building element having two wire mesh mats interconnected by web wires enclosing an insulating body with concrete applied to each side of the panel using the shotcrete process. The concrete shells are then interconnected by holes formed in the insulating body which fills with concrete and interconnecting the two shells.
However, none of the above described systems of forming a structure from preformed three dimensional building elements can do so efficiently and quickly since each requires various degrees of finishing and modifications at the job site. In particular, the shotcrete formulation is applied to both sides of the panel or to both the interior wall and the exterior wall portions of the element forming the structure.
A structure's interior walls have very different requirements than the exterior walls. For example, interior walls are often required to be smooth and to easily accept nails for hanging items. Exterior walls are typically rough, such as in stucco finishes and are required to be durable to withstand the elements. The interior walls of the structure formed using shotcrete require a separate step often involving an application of second or third cementitious or plaster compound to produce a smooth soft finish. This extra step in finishing the interior walls requires both time and money.
Accordingly, it would advantageous to provide a method and system that could efficiently and quickly improve the construction process in the formation of a structure using a three dimensional building element. Furthermore, it would be advantageous if the steps of forming and finishing the interior wall portion could be reduced to save both time and money during the construction process.

SUMMARY

The present system includes a three dimensional building element and a method of forming a three dimensional building element wherein the densities of the outer cementitious shells differ. In particular, the outer shell forming the exterior portion of the building element has a density greater than the interior shell to provide in part structural strength. The interior shell is formed from a lower density cementitious compound to provide an interior wall portion of a structure with a smooth finished appearance. The lower density cementitious compound enables the interior shell to obtain a smooth finished appearance without the need to apply various secondary coatings such as plaster or drywall.
In greater detail, the three dimensional building element includes two parallel welded wire mesh mats with individual web wires joined at each end to the mats for keeping the mats at a predetermined distance from each other. The individual web wires are arranged in rows connecting the two wire mesh mats. An insulating body spanning more than two of the rows of web wires is positioned between the two wire mesh mats at a predetermined distance. The insulating body is further pierced by the web wires.
The exterior cementitious outer shell of the building element is in communication with (or encases) one of the two wire mesh mats. Additionally, the interior cementitious outer shell in communication with (or encases) the other of the two wire mesh mats. The exterior cementitious outer shell has a density greater than the density of the interior cementitious outer shell.
In one embodiment, the ratio of the density of the exterior cementitious outer shell to the density of the interior cementitious outer shell is greater than 1.1 to 1, in a further embodiment the ration is greater than 1.2 to 1 and an additional embodiment includes a ratio greater than 1.5 to 1. Example densities of the exterior cementitious outer shell include those between about 100 pcf to about 145 pcf and example densities of the interior cementitious outer shell include those between about 55 pcf to about 110 pcf.
A further embodiment of the present system includes the ratio of the compressive strength of the exterior cementitious outer shell to the compressive strength of the interior cementitious outer shell being greater than 1.1 to 1, in a further embodiment the ration is greater than 1.2 to 1 and an additional embodiment includes a ratio greater than 1.5 to 1. Example compressive strengths of the exterior cementitious outer shell include those between about 2,500 psi to about 8,800 psi. and example compressive strengths of the interior cementitious outer shell includes those between about 2,000 psi to about 5000 psi.
In an additional embodiment the interior cementitious outer shell includes a foam admixture which reduces the density of the shell. Furthermore the fire resistance and moisture resistance of the interior cementitious outer shell may be increased by the addition of fly ash.
A further embodiment of the three dimensional building element includes the combination of the ratios of densities of the respective exterior and interior outer shells and their respective density values. Thus, in this embodiment the ratio of the density of the exterior cementitious outer shell to the density of the interior cementitious outer shell is greater than 1.2 to 1 and the density of the exterior cementitious outer shell is between about 100 pcf to about 150 pcf and the density of the interior cementitious outer shell is between about 50 pcf to about 110 pcf.
In an additional embodiment, the three dimensional building element includes the combination of both the density ratios and compressive strength ratios of the respective outer cementitious shells. Thus, in this embodiment the ratio of the density of the exterior cementitious outer shell to the density of the interior cementitious outer shell is greater than 1.2 to 1 and the ratio of the compressive strength of the exterior cementitious outer shell to the compressive strength of the interior cementitious outer shell is greater than 1.2 to 1. In addition, the embodiment includes the interior cementitious outer shell including a foam admixture.
The system also includes a method of forming a three dimensional building element. The method includes the steps of providing two parallel welded wire mesh mats with individual web wires joined at each end to the mats for keeping the mats at a predetermined distance from each other. The individual web wires are arranged in rows connecting the two wire mesh mats. The method further includes piercing an insulating body positioned between the wire mesh mats by the web wires. Further included in the method is the application of a cementitious composition to one of the two wire mesh mats to form an exterior outer shell and the application of a second cementitious composition to the other of the two wire mesh mates to form an interior outer shell. The ratio of the first and second cementitious composition is greater than 1.1 to 1.
The method may also include in a further embodiment the application to the interior cementitious outer shell a composition comprising a drywall powder and primer based paint. The applied composition comprising a drywall powder and primer based paint may be sanded to a level wall finish of between about 4 to about 5 according to ASTM C 840 standard.

DRAWINGS

In the drawings:

FIG. 1 is an axonometric view of a three dimensional building element according to the invention;

FIG. 2 is a plan view of the three dimensional building of the present system and method as shown in FIG. 1; and

FIG. 3 is an interior cross sectional view of a three dimensional panel comprising a three-dimensional grid body having an insulating foamed body formed within, and further including the exterior outer cementitious shell and the interior cementitious outer shell and interior cementitious outer shell.

DETAILED DESCRIPTION

Disclosed is a three dimensional building element and method of forming a three dimensional building element wherein the densities of the outer cementitious shells differ. In particular, the interior outer shell or that shell forming an interior wall portion of a structure has a density less than the density of the exterior shell forming the exterior portion of the structure. The reduced density of the cementitious interior shell enables the shell to obtain a smooth finished appearance without the need to apply various secondary coatings such as plaster or drywall.
The outer shells of the three dimensional building element are formed from a cementitious composition. The cementitious composition may be varied such that the densities of the shells may differ wherein the exterior shell has a density greater than the interior shell. The cementitious composition may be applied to the three dimensional building element by using several techniques including dry or wet cementitious applications to a prescribed thickness.
As an alternative to the shotcrete process the cementitious composition may be applied to the building element using a small batch process. The small batch process may include the use of a foam generator such as that available from Goodson & Associates of Wheat Ridge, CO and known as the Goodcell Foam Generator, for producing a foamed cementitious composition. By using a small batch process the cementitious composition can be applied to the building element using relatively unskilled labor saving the expense of using a skilled shotcrete operator. Furthermore, individual mixes for various wall portions of the structure can be easily mixed for the structural load of the building element or type of finish desired. Additionally, only portions of the structure can be worked on at a time.
The strength of the cementitious composition can vary based upon application and load factors. Furthermore the cementitious composition may be varied based upon other performance criteria. However, the density of the formed interior cementitious outer shell is always less than the density of the formed exterior cementitious outer shell of the three dimensional building element.
The present system may use several mix variations from the formulas set forth for different purposes within a specific building project. For example, an interior, non-load bearing walls may receive a lower strength concrete application.
The exterior cementitious outer shell may be comprised of a concrete mix with multiple admixtures. Admixtures maybe added to reduce water intrusion through the finished panel; improve compressive and tensile strength of the concrete; and reduce cracking related to moisture loss, commonly referred to as shrinkage cracking. The compressive strength of the mix may vary between 2500 psi and 8,000 psi, and the density of the mix may be varied between 100 pcf and 145 pcf based on the requirements of a specific application. Such concretes are ideal for exterior finishes and walls requiring higher-strength, including shear walls.
The interior cementitious outer shell may be comprised of a concrete mix with multiple admixtures. The purpose of the admixtures in the interior cementitious outer shell is to in part to lower the density of the concrete, while maintaining required strength. Lowered concrete density results in lighter wall and floor and roof systems. In addition, a more aesthetically pleasing interior finish is achieved allowing for smooth walls, pictures to be hung and wood trim to be installed. The compressive strength of the mix may vary between 2000 psi and 5,000 psi, and the density of the mix may be varied between 55 pcf and 110 pcf based on the requirements of a specific application. Such concretes are ideal for interior finishes.
By way of example, and not limitation, the mix components of can include:
Exterior Mix forming the Exterior Cementitious Outer Shell

- 800 lb—Portland Cement (type 1)
- 2240 lb—Sand
- 30 gal—Water
- 15 lb—Kalmatron Additive KC-A

Interior Mix forming the Interior Cementitious Outer Shell

- 800 lb—Portland Cement (type 1)
- 2240 lb—Sand
- 28 gal—Water
- 10 ft³—Foam admixture such as that available from Goodson & Associates of Wheat Ridge, CO and known as GoodCell Foam Additive made using Goodcell Type A-100 chemical

Furthermore, the three dimensional building element may include an elastomeric coating to aid in securring the foam and the mesh during transit. Additionally, the elastomeric coating may assist in securing any mechanical/electrical/plumbing material after the material has been installed in the dimensional building element and to work as a bonding agent to adhere the concrete to the panel system.
An additional embodiment of the present system includes a further finishing process to achieve an even more finished flat and level interior wall finish to a degree of about a 4 to 5 finish according to ASTM C840 standard. The interior finish is applied after the curing of the interior cementitious composition. The interior finishing material is comprised of drywall powder and a primer based paint. The drywall powder is mixed into the primer based paint and then sprayed or rolled onto the interior surface. After the primer and powder mix has cured, the interior surface is sanded smooth to the desired finish.
A further embodiment for non-load bearing exterior walls includes using only an exterior cementitious outer shell with a gypsum sheathing applied to the interior side of the wall. To satisfy code wind loads provisions in high wind areas, portions of the insulating foam may be removed to allow structural concrete ribs to be added to the system during cementitious coating application.
Referring now in greater detail to the drawings in which like numerals indicate like items throughout the several views, FIGS. 1-3 depict the present three dimensional building element and method of forming a three dimensional building element, in the various embodiments of the present invention.
The three dimensional building element as shown in FIGS. 1-3 is formed of outer and inner wire mesh mats 1 and 2 respectively, which are arranged parallel to and at a predetermined distance from each other. Each wire mesh mat 1 or 2 has several longitudinal wires 3 or 4 and several cross wires 5 or 6 which cross each other and are welded together at the points of intersection. The distance between the longitudinal wires 3, 4 and between the cross wires 5, 6 is selected according to the static requirements of the structural member, and for example is within the range of 50 to 150 mm. The distances can be equal, or different.
The diameters of the longitudinal and cross wires 3, 4 or 5, 6 are also selectable according to the static requirements and are preferably within the range from 2 to 6 mm. The surface of the wire mesh mats 3, 4, 5, 6 can be, within the scope of the invention smooth or ribbed.
The two wire mesh mats 1, 2 are joined together by several web wires 7, 7′ into a dimensionally stable mesh body. The web wires 7 are welded at their respective ends to the wires of the two wire mesh mats 1, 2, wherein, within the scope of the invention, the web wires 7 are welded either, to the respective longitudinal wires 3, 4 or to the cross wires 5, 6. The web wires 7 are arranged obliquely alternately in opposite directions, or. like a trellis as a result of which the mesh body is reinforced against shear stress.
An insulating body 8 is arranged in the gap between the wire mesh mats 1, 2, at a predetermined distance from the wire mesh mats. The insulating body 8 has top and bottom, or outside and inside surfaces 9 which run parallel to the wire mesh mats 1, 2. The insulating body 8 serves for heat and sound insulation and for example is made of foam plastics such as polystyrene or polyurethane foam.
The thickness of the insulating body 8 is freely selectable and is, for example, within the range from 20 to 200 mm. The distances from the insulating body 8 to the wire mesh mats 1, 2 are also freely selectable and are, for example, within the range from 10 to 30 mm. The structural member can be made in any length and width. On the basis of the method of production, a minimum length of 100 cm and standard widths of 60 cm, 100 cm, 110 cm, 120 cm have proved to be advantageous.
The exterior cementitious outer shell 14 of the building element is in communication with (or encases) one 2 mat of the two wire mesh mats 1, 2. As shown in FIG. 3 the exterior cementitious outer shell 14 encases the entire wire mesh mat 2 and protrudes beyond the mat 2. The thickness of either the interior 13 or exterior 14 cementitious outer shell can vary depending upon the desired strength for the building element and the application of the element. Furthermore, as shown in FIG. 3, the interior cementitious outer shell 13 is in communication with (or encases) the other 1 mat of the two wire mesh mats 1, 2. The thicknesses of the interior cementitious outer shell 13 and the exterior cementitious outer shell 14 can be different or the same. The exterior cementitious outer shell 14 has a density greater than the density of the interior cementitious outer shell 13. Furthermore, the mix formulations of the cementitious composition comprising the exterior cementitious outer shell 14 can be different form the interior cementitious outer shell 13.
In one embodiment, the ratio of the density of the exterior cementitious outer shell 14 to the density of the interior cementitious outer shell 13 is greater than 1.1 to 1, in a further embodiment the ration is greater than 1.2 to 1, a further embodiment includes a ratio greater than 1.3 to 1 and an additional embodiment includes a ratio greater than 1.5 to 1.
By way of example and not limitation, the densities of the exterior cementitious outer shell 14 include those between about 100 pcf to about 145 pcf. Example densities of the interior cementitious outer shell 13 include those between about 55 pcf to about 110 pcf. Further examples include the densities of the exterior cementitious outer shell 14 include between about 100 pcf to about 150 pcf. and example densities of the interior cementitious outer shell 13 include those between about 50 pcf to about 120
A further embodiment of the present system includes the ratio of the compressive strength of the exterior cementitious outer shell 14 to the compressive strength of the interior cementitious outer shell 13 being greater than 1.1 to 1, in a further embodiment the ration is greater than 1.2 to 1 and in an additional embodiment the ratio is greater than 1.5 to 1. Example compressive strengths of the exterior cementitious outer shell 14 include those between about 2,500 psi to about 8,800 psi. and example compressive strengths of the interior cementitious outer shell 13 includes those between about 2,000 psi to about 5000 psi.
While applicants have set forth embodiments as illustrated and described above, it is recognized that variations may be made with respect to disclosed embodiments. Therefore, while the invention has been disclosed in various forms only, it will be obvious to those skilled in the art that many additions, deletions and modifications can be made without departing from the spirit and scope of this invention, and no undue limits should be imposed except as set forth in the following claims.

Claims

1. A three dimensional building element comprising:

two parallel welded wire mesh mats and individual web wires joined at each end to the mats for keeping the mats at a predetermined distance from each other, the individual web wires being arranged in rows connecting the two wire mesh mats;

an insulating body spanning more than two of the rows of web wires and defining two opposite surfaces arranged parallel to and positioned between the wire mesh mats and at a predetermined distance therefrom, the insulating body being pierced by the web wires; and

an exterior cementitious outer shell in communication with one of the two wire mesh mats and an interior cementitious outer shell in communication with the other of the two wire mesh mats, wherein the exterior cementitious outer shell has a density greater than the density of the an interior cementitious outer shell.

2. The three dimensional building element of claim 1, wherein the ratio of the density of the exterior cementitious outer shell to the density of the interior cementitious outer shell is greater than 1.1 to 1.

3. The three dimensional building element of claim 1, wherein the ratio of the density of the exterior cementitious outer shell to the density of the interior cementitious outer shell is greater than 1.5 to 1.

4. The three dimensional building element of claim 1, wherein the density of the exterior cementitious outer shell is between about 100 pcf to about 145 pcf.

5. The three dimensional building element of claim 1, wherein the density of the interior cementitious outer shell is between about 55 pcf to about 110 pcf.

6. The three dimensional building element of claim 1, wherein the compressive strength of the exterior cementitious outer shell is between about 2,500 psi to about 8,800 psi.

7. The three dimensional building element of claim 1, wherein the compressive strength of the interior cementitious outer shell is between about 2,000 psi to about 5000 psi.

8. The three dimensional building element of claim 1, wherein the interior cementitious outer shell includes a foam admixture.

9. The three dimensional building element of claim 8, wherein the interior cementitious outer shell further includes fly ash.

10. A three dimensional building element comprising:

an insulating body spanning more than two of the rows of web wires and defining two opposite surfaces arranged parallel to and positioned between the wire mesh mats and at a predetermined distance therefrom, the insulating body being pierced by the web wires;

an exterior cementitious outer shell in communication with one of the two wire mesh mats and an interior cementitious outer shell in communication with the other of the two wire mesh mats, wherein the exterior cementitious outer shell has a density greater than the density of the an interior cementitious outer shell; and

wherein the ratio of the density of the exterior cementitious outer shell to the density of the interior cementitious outer shell is greater than 1.2 to 1 and wherein the density of the exterior cementitious outer shell is between about 100 pcf to about 150 pcf and the density of the interior cementitious outer shell is between about 50 pcf to about 110 pcf.

11. The three dimensional building element of claim 10, wherein the compressive strength of the exterior cementitious outer shell is between about 2,500 psi to about 8,800 psi.

12. The three dimensional building element of claim 10, wherein the compressive strength of the interior cementitious outer shell is between about 2,000 psi to about 5000 psi.

13. The three dimensional building element of claim 10, wherein the interior cementitious outer shell includes a foam admixture.

14. The three dimensional building element of claim 13, wherein the interior cementitious outer shell further includes fly ash.

15. A three dimensional building element comprising:

an exterior cementitious outer shell in communication with one of the two wire mesh mats and an interior cementitious outer shell in communication with the other of the two wire mesh mats, wherein the exterior cementitious outer shell has a density greater than the density of the an interior cementitious outer shell;

wherein the ratio of the density of the exterior cementitious outer shell to the density of the interior cementitious outer shell is greater than 1.2 to 1 and wherein the ratio of the compressive strength of the exterior cementitious outer shell to the compressive strength of the interior cementitious outer shell is greater than 1.2 to 1; and

wherein the interior cementitious outer shell includes a foam admixture.

16. The three dimensional building element of claim 15, wherein the interior cementitious outer shell further includes fly ash.

17. The three dimensional building element of claim 15, wherein the compressive strength of the exterior cementitious outer shell is between about 2,500 psi to about 8,800 psi.

17. The three dimensional building element of claim 15, wherein the compressive strength of the interior cementitious outer shell is between about 2,000 psi to about 5000 psi.

18. A method of forming a three dimensional building element comprising the steps of:

providing two parallel welded wire mesh mats and individual web wires joined at each end to the mats for keeping the mats at a predetermined distance from each other, the individual web wires being arranged in rows connecting the two wire mesh mats;

providing an insulating body spanning more than two of the rows of web wires and defining two opposite surfaces arranged parallel to and positioned between the wire mesh mats and at a predetermined distance therefrom, the insulating body being pierced by the web wires;

applying a first cementitious composition to one of the two wire mesh mats to form an exterior outer shell;

applying a second cementitious composition to the other of the two wire mesh mats to form an interior outer shell; and

wherein the ratio of the density of the first cementitious composition applied to the exterior cementitious outer shell to the density of second cementitious composition applied to the interior cementitious outer shell is greater than 1.1 to 1.

19. The method of claim 18, wherein the ratio of the density of the exterior cementitious outer shell to the density of the interior cementitious outer shell is greater than 1.2 to 1 and wherein the ratio of the compressive strength of the exterior cementitious outer shell to the compressive strength of the interior cementitious outer shell is greater than 1.2 to 1.

20. The method of claim 18, wherein the applied cementitious composition applied to the other of the two wire mesh mates to form an interior outer shell includes a foam admixture.

21. The method of claim 20, wherein the applied cementitious composition applied to the other of the two wire mesh mates to form an interior outer shell includes fly ash.

22. The method of claim 19, further includes applying to the interior cementitious outer shell a composition comprising a drywall powder and primer based paint.

22. The method of claim 22, further including sanding the applied composition comprising a drywall powder and primer based paint to a level wall finish of between about 4 to about 5 of ASTM C 840 standard.