US 3578732 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
2 Sheets-Sheet 1 INVENTOR ISA FIG. 4
V D.L our/r.
J ATTORNEY FIG.6
5. c. LOUNT ETAL METHOD OF FORMING BUILDING WALLS .Im lIlll'lvlllfllll /IOA [l'lllllll May 11 1971 Filed cm. 21, 1968 May 11, 1971 c, LOUNT ETAL 3,578,732
METHOD OF FORMING BUILDING WALLS Filed Oct. 21, 1968 2 Sneets-Sheet 2 TTTTTTTT INVENTOR 62191-091! lag z- BY I v W 113% ATTORNEY United States Patent U.S. Cl. 264-34 12 Claims ABSTRACT OF THE DISCLOSURE This method of forming walls is primarily for multistoried, column supported buildings and consists of placing a plurality of vertically situated spaced and parallel tendons or cables through the wall opening, then prestressing same, and then attaching a Wire grid or equivalent to the tendons or cables. Under certain circumstances a form is then placed in spaced and parallel relationship from the tendons or cables and the grid and then a wall material that sets up by chemical action is sprayed or trowelled through and around the tendons or cables and the grid so that the said tendons or cables and grid are fully embedded in the material.
This invention relates to new and useful improve ments in the construction and method of construction of walls for buildings.
The invention can be used on buildings of the lift slab type, on buildings with cast in-place floor slabs and columns, on steel frame buildings with floor slabs secured thereto and in fact any type of building which consists of a plurality of combination floor and ceiling slabs horizontally situated in spaced and parallel relationship and supported spaced and parallel vertical columns around or adjacent the perimeter thereof thus defining, with said slabs, substantially rectangular wall receiving apertures. Although the present specification describes the construction of outer walls, nevertheless it should be noted that the method can be and is used for the construction of inner room walls, corridor walls, elevator shaft walls and the like.
It is conventional to build said walls with courses of brick together with courses of cement or cinder block spaced from the brick which, as required by the majority of building codes, results in a finished wall of this nature measuring some 8 to 12 inches in thickness. To this must be added the thickness of conventional insulation and finishing materials so that the total wall thickness often approaches 12 inches. The principal disadvantages of such a wall construction are firstly the high labour and material costs in building such walls and secondly, the loss of floor space due to the thickness of the walls which is considerable.
Another conventional method of building walls for such buildings consists of precasting a stressed or unstressed wall panel with cement or the like either on site or remote from the building site and then hoisting these precast panels into position and securing same within the opening.
Although these walls may not be as thick as conventional masonry walls, nevertheless there is an excessive cost factor involved in the production and setting in place of such precast walls. Furthermore, sufficient reinforcing material must be incorporated in these panels to give sufiicient strength to the panels so that they can be lifted and manouvered into position. This reinforcing is often in excess of the requirements for the wall panel once it is in place thus resulting in excessive costs for this reinforcing material.
Patented May 11, 1971 ice position and secondly because the wall thickness need not exceed 2 inches.
The principal object and essence of the invention is therefore to provide a built in-place wall structure which, due to the inclusion of prestressed tendons or stranded cables and reinforcing grid or the like, enables sufiicient strength to be developed with a relatively thin cross section, said strength being sufiicient to satisfy normal building codes.
Another object of the invention is to provide a method of the character herewithin described which can either build upon an outer form thus giving a prefinished outer surface or, alternatively, can build upon an inner form which may be a rigid sheet of insulation material which in turn leads to further savings in labour. This particular method enables the outer surface to be finished with decorative aggregate or any other architectural finishes. A further method includes the use of expanded metal lath attached to the tendons or cables thus enabling the wall material to be trowelled on and through the lath thus eliminating the necessity for forms.
Another object of the invention is to provide a method of the character herewithin described which enables outer walls to be built approximately four times faster than conventional masonry walls once again leading to extensive cost savings.
Summarizing, the method consists of the provision of spaced and parallel prestressed tendons or cables extending through the wall reciving openings, to which a reinforcing metal grid or expanded metal lath is secured. A form may then be placed on one of the other sides of this cable and grid structure and spaced therefrom whereupon Wall material as defined is sprayed or trowelled from the opposite side, through the grid and tendons or cables onto the form and built up so that the grid and tendons or cables are embedded completely Within the wall material.
With the foregoing in view, and such other or further purposes, advantages or novel features as may become apparent from consideration of this disclosure and specification, the present invention consists of the inventive concept which is comprised, embodied, embraced, or included in the method, process, construction, composition, arrangement of parts, or new use of any of the foregoing, herein exemplified in one or more specific embodiments of such concept, reference being had to the accompanying drawings in which:
FIG. 1 is a partially schematic fragmentary view showing a plurality of floor slabs with one wall section in place.
FIG. 2 is a fragmentary side elevation of one floor slab showing an alternative method for guiding the cables.
FIG. 3 is an enlarged fragmentary view of the end of one floor slab showing one method of attaching the forms.
FIG. 4 is a partially schematic front elevation of a wall section with the grid and wires in place.
FIG. 5 is a fragmentary view similar to FIG. 1 but showing an alternative method.
FIG. 6 is a fragmentary front elevation of a Wall section showing one method of window placement.
FIG. 7 is a plan view of one section of the reinforcing wire grid.
FIG. 8 is a partially schematic front elevation of a combination tendon and grid construction.
FIG. 9 is an isometric view of one edge of a floor slab showing the tendons and hangers for the wall of FIG. 8.
FIG. 10 is a fragmentary section of a wall showing the use of an expanded metal lath.
FIG. 11 is a view similar to FIG. 1 but showing a further embodiment.
In the drawings like characters of reference indicate corresponding parts in the different figures.
Proceeding therefore to describe the invention in de tail, reference should first be made to FIG. 1 in which illustrates combination floor and ceiling slabs normally for-med from reinforced concrete and either produced as a cast in-place floor, by the well known lift slab process or by any other conventional method.
In this particular view, the conventional spaced and parallel vertically situated columns are not shown but these are indicated by reference character 11 in FIGS. 4 and 6.
Adjacent pairs of spaced and parallel combination floor and ceiling slabs 10, in combination with adjacent pairs of vertically situated spaced and parallel columns 11, define wall receiving spaces 12 usually rectangular in configuration. These may be either outer or inner wall spaces.
We provide a plurality of fairly closely spaced, vertically extending solid steel tendons or stranded cables 13 extending through the wall receiving spaces 12. Reference to FIG. 1 will show that these tendons or cables 13 extend freely through apertures 14 situated adjacent to the edges 15 of the slabs, said apertures being vertically above one another as clearly indicated. Under normal circumstances these rods or tendons develop suflicient strength for the walls but if additional strength is required then these can be replaced with stranded wire cable. However the term cable includes both single tendons and stranded cable.
Means 16 are provided at the upper and lower slabs 10A and 103, respectively, so that these tendons or cables can be pre-stressed between the upper and lower slabs and then locked in position. There are various means for accomplishing this pre-stressing and locking condition which are conventional so that it is not believed necessary to supply details in this specification.
As an alternative to the apertures 14 formed adjacent the perimeters of the slabs 10, ring bolts 17 may be cast in place extending from the perimeters 15 as shown in FIG. 2 through which the tendons or cables extend or the method illustrated in FIGS. 9 and 11 may be used as will hereinafter be described.
As a further alternative, the prestressed tendons or cables 13 may extend between adjacent floors only as illustrated by reference characters 10C and 10D in FIG. 4.
A substantially rectangular section 18 of reinforcing wire grid is secured to the plurality of prestressed tendons or cables 13 extending through a wall section aperture 12 and FIG. 7 shows a plan view of these wire grid sections. They are conventional and consist of a plurality of vertical wires 19 together with a plurality of horizontal wires 20 all in spaced and parallel relationship and connected at the intersections thereof by spot welding or the like as indicated by reference character 21. These sections 18 are wired to the cables by means of wire ties 22 either upon the inner side of the cables as illustrated in the drawings or, alternatively, upon the outside if desired.
In the preferred embodiment, a substantially rectangular form 23 of plywood or the like is then secured to the outer perimetrical edges 15 of the slabs 10 and the vertical edges of the columns 11 thus enclosing the space 12 spaced from the cables 13 and the grid 18.
Various methods may be used to detachably secure this form 23 in place and FIG. 3 shows one such method.
A bolt or fastening device 24 is cast in-place when the floor slabs 10 are formed and extend outwardly from the perimetrical edge 15. A longitudinal whaling strip 25 is secured against the perimetrical edge 15 by means of nut 26 engaging over bolt 24 and a shoulder 27 is left between the whaling strip and the undersurface 28 of the floor slab to receive the edge of the form 23 as clearly shown. A clip or clamp 29 then engages over the shouldered portion 30 of the whaling strip and the outer surface 31 of the form 23 thus holding it in place.
With this form in place as shown in FIG. 1, a conventional cement plaster gun or the like (not illustrated) is used to spray the wall material from the inside, through the wire grid 18 and through the tendons or cables 13 onto the inner surface 32 of the form and this material is gradually built up until the prestressed tendons or cables 13 and the grid 18 is completely covered and immersed within this material. Alternatively, the materialcan be trowelled into place.
The material used can be any of the conventional plaster cements or similar material. For example, urethane can be used which gives a water and vapour proof wall section and of course, waterproofing additives can be incorporated in the conventional cement plasters.
In the claims accompanying this specification, the term settable wall material includes any material which can be sprayed on or trowelled on and then sets up and hardens due to chemical action.
The inner surface 33 of the wall material is then smoothed by trowel if necessary and, when the wall material has set sutficiently, the form 23 may then be removed. Conventional insulation and internal finishing materials (not illustrated) may then be secured to the iner surface 33 to finish the wall.
Due to the smooth inner surface 32 of the form 23 and also due to the pressure of the wall material striking this surface from the gun, the outer surface of the wall presents an extremely smooth and finished face when the forms are removed.
If desired, the initial wall coat may be of a finishing material such as medusa cement and the remainder of the wall may then be built up with conventional coarse grade wall material. This gives a stark white or colored smooth outer surface to the finished wall.
The total thickness of the wall once it is finished as illustrated in FIG. 1, is approximately 2 inches with the tendons or cables and wire grid being substantially in the center thereof.
Alternatively, the method shown in FIG. 5 may be. used. In this method, the form consists of a rectangular slab of rigid insulation material 34 made from expanded polystyrene or the like and this is secured in place by means of temporary battens 35 and spaced from the cables 13 and wire grid 18.
With this embodiment, the wall material is sprayed or trowelled from the outside inwardly upon the outer surface of the insulating sheet 34 and is then built up to the required thickness once again embedding the cables 13 and the wire grid 18 within the wall mass.
The outer surface 35 of this wall may be trowelled smooth and granite chips or decorative aggregate or other architectural finishing materials may be trowelled into position. Although scaffolding is required for this particular embodiment, savings are evident inasmuch as the insulation is installed and acts as the form.
It may be necessary to provide window spaces and in modern architecture, such windows are usually relatively narrow vertically situated apertures as shown in FIG. 6. Under these circumstances, a window form 36 may be secured in the desired position between adjacent cables 13 and, if desired, relatively short cables 13 may extend from the head and base members 37 of the window form. Once the wall has been formed, the conventional window assemblies may be inserted.
If, however, larger windows are required, then cross rods 13A or tendons may be Welded to the ends of the tendons above and below the window form. These are shown in phantom in FIG. 6. Alternatively, the tendons or cables may extend through the mullions of the window frames.
FIGS. 9 and 11 show a further embodiment of the wall structure in which the wall is situated entirely outboard of the edges 15 of the slabs 10. In this embodiment, sheets of rigid insulation material 34 are secured within the inner sides of the wall receiving spaces 12, being supported by means of battens 35. It should also be noted that relatively thin strips of insulation 34 cover the edges 15 of the slabs 10.
Vertically situated tendons or cables 13 extend from the uppermost slabs to the lowermost passing freely past the edges 15. However, it is necessary to locate and position these tendons or cables 13 and in this connection I have provided metal staples or the like 38 which extend from the edges 15 of the slabs 10. These consist of a pair of spaced and parallel legs 39 embedded by the inner ends thereof 40, within the slab and extending outwardly therefrom. A cross bar 41 spans the outer ends 42 of these legs as clearly shown, said cross bars being spaced and parallel to the edge of the lab. The tendons or cables 13 are located within the corners 43 between said other ends 42 and the ends of the cross bars 41 as clearly shown in FIG. 9. A wire mesh grid 18 is secured to the tendons or cables by means of ties 44 substantially enclosing the wall receiving aperture 12 thus enabling the Wall material to be deposited either by trowelling or spray, from the outside, through the grid 18 and past tendons or cables 13 onto the outer surface of the insulation panel 34. This material is indicated by the reference character 45 in FIG. 11.
Inasmuch as this wall is outboard of the edges 15 of the slabs, means are required to support the static weight thereof. These take the form of a plurality of anchor members 46 which include horizontal portions or legs 47 embedded within the edge 15 of the slab 10 and extending outwardly therefrom, and vertical portions 48 being formed integrally with the portions 47 and at right angles thereto. These vertical portions extend downwardly as clearly shown in FIG. 9 and are spaced from the slab edge 15 by an amount substantially equal to the spacing of the tendons or cables 13 so that these anchors are also embedded within the wall material thus acting as hangers for the finished wall.
A form may be required to control the thickness of the material and to provide a straight edge. The groove or recess 49 left when the form is removed is grouted as at 50.
Reference should also be made to FIG. 10 which shows a method of forming the wall in which the wire grid is replaced by a section of expanded metal lath 51. This section of metal lath is secured to the tendons or cables 13 by wire ties (not illustrated) thus enabling the wall finishing material 52, to be trowelled through the tendons or cables 13 and through the interstices (not illustrated) of the metal lath 51. This provides sufiicient anchor to the material and eliminates the necessity for a form. Both the outer and inner surfaces 54 may be trowelled smooth and, if necessary, decorative aggregate or similar a-rchitectural finishing material 55 may be embedded upon the outer surfaces 53 which may be built up by trowelling further material thereon.
FIG. 8 shows a further embodiment of the invention in which the tendons or cables and the grid are manufactured as one unit which may be rolled up for transportation and storage. a
It comprises a plurality of spaced and parallel tendons or cables 13B together with a plurality of wire or rod reinforcing members 13C extending across the tendons or cables at right angles thereto and in spaced and parallel relationship and being spot welded or otherwise se cured at the interstices thereof. As an example, the ten dons or cables 13A may be 12 or 16 inches apart and the reinforcing members 13B at 4-inch spacings depending on the design parameters.
In use the roll is taken to the upper floor of the building and unrolled down the outside thereof and then anchored and prestressed in the usual way. Of course, this arrangement can only be used for outer walls and for walls that are built outboard of the slab edges as shown in FIGS. 9 and 11.
In all embodiments it should be stressed that one of the most important aspects of the invention is the strength developed in the relatively thin cross section due to the prestressed tendons or cables. This strength gives the necessary resistance to sideways pressures particularly on outside walls.
Finally, the term plastic in the phrase settable plastic wall material describes the fluid characteristics of the material and not the chemical composition thereof.
Various modifications can be made within the scope of the inventive concept disclosed. Accordingly, it is intended that what is described herein should be regarded as illustrative of such concept and not for the purpose of limiting protection to any particular embodiment thereof, but that only such limitations should be placed upon the scope of protection to which the inventors hereof are entitled, as justice dictates.
What is claimed to be the present invention is:
1. A method of forming walls for buildings which include a plurality of spaced and parallel horizontally disposed combination floor and ceiling slabs of reinforced concrete, and a plurality of spaced and parallel vertically situated columns extending between adjacent slabs thereby defining with said slabs, wall receiving spaces; said method comprising the steps of placing a plurality of spaced and parallel steel cables through said wall receiving spaces and extending vertically from an upper slab to the lower slab, said cables passing freely through the intermediate slabs, stretching said cables to prestress same and anchoring same by the ends thereof to an upper and lower slab, attaching a grid of reinforcing wire or the like to said cables between adjacent slabs and between adjacent columns, placing a form on one side of said cables and grid and spaced therefrom to enclose the wall receiving space between said adjacent slabs and adjacent columns, and then depositing settable plastic wall material from the side opposite said form, through said grid and cables onto said form and continuing building up said material until said grid and said cables are completely covered by and immersed in said material, letting said material set, and then stripping oif the said form.
2. A method of forming walls between adjacent floor slabs and columns of a building consisting of the steps of placing a plurality of spaced and parallel vertically situated cables between adjacent slabs, prestressing said cables and then anchoring same by the ends thereof, attaching a grid of reinforcing wire or the like to said cables between adjacent slabs and between adjacent columns, placing a form on one side of said cables and grid and spaced therefrom to enclose the area between said adjacent slabs and adjacent columns, and then depositing settable plastic wall material from the side opposite said form, through said grid and cables onto said form and continuing building up said material until said grid and cables are completely covered by and immersed in said material, letting said material set and then stripping olf said form.
3. The method according to claim 1 in which said form is placed on the outside of the said grid and cables.
4. The method according to claim 2 in which said form is placed on the outside of the said grid and cables.
5. The method according to claim 1 in which said form comprises a sheet of rigid insulation placed inboard of said grid and cables.
6. The method according to claim 2 in which said form comprises a sheet of rigid insulation placed inboard of said grid and cables.
7. The method according to claim 1 in which said slabs are apertured above and below said wall receiving spaces, said cables running freely through said apertures, and which include the additional step of depositing a finishing coat of material onto said form and then c0ntinuing by depositing coarser grade material.
8. The method according to claim 4 in which said slabs are apertured above and below said wall receiving spaces, said cables running freely through said apertures, and which include the additional step of depositing a finishing coat of material onto said form and then continuing by depositing coarser grade material.
9. A method of forming walls for buildings which include a plurality of spaced and parallel horizontally disposed combination floor and ceiling slabs of reinforced concrete, and a plurality of spaced and parallel vertically situated columns extending between adjacent slabs thereby defining, with said slabs, Wall receiving spaces: said method comprising the steps of placing a plurality of spaced and parallel steel cables through said wall receiving spaces from an upper slab to a lower slab, said cables passing freely through the wall receiving spaces, stretching said cables to prestress same, and anchoring same by the ends thereof to said upper and lower slabs, attaching a grid of expanded lath to said cables within said wall receiving spaces, then trowelling on a settable plastic Wall material through said cables and through the interstices in said metal lath thereby embedding said lath and cables within said wall material.
10. The method according to claim 9 which includes the additional step of smoothing the material extruded through said interstices.
11. The method according to claim 2 in which said slabs are apertured above and below said Wall receiving spaces, said cables running freely through said apertures, and which include the additional step of depositing a finishing coat of material onto said form and then continuing by depositing coarser grade material.
12. The method according to claim 3 in which said slabs are apertured above and below said wall receiving spaces, said cables running freely through said apertures, and which include the additional step of depositing a finishing coat of material onto said form and then continuing by depositing coarser grade material.
References (Iited UNITED STATES PATENTS 11,522,046 vl 1925 Campbell 25l'31 1,884,462 10/1932 Willson 52228 2,260,058 10/ 1941 Sanford 52-227 2,358,147 9/1944 Colburn 25131 2,964,821 12/1960 Meehan 264-34X 2,837,776 6/ 1958 Klein 52-223X ROBERT F. WHITE, Primary Examiner R. H. SHEAR, Assistant Examiner U.S. C]. X.R. 25-418; 264-35