CA1145583A

CA1145583A - Building construction

Info

Publication number: CA1145583A
Application number: CA000360021A
Authority: CA
Inventors: Denis R. Loranger
Original assignee: Individual
Current assignee: Individual
Priority date: 1980-09-10
Filing date: 1980-09-10
Publication date: 1983-05-03

Abstract

BUILDING CONSTRUCTION
Abstract A square or rectangular concrete floor slab is first formed, although other shapes, such as circular, are also envisaged. A reinforced concrete column extends vertically upwardly from a generally central location on the floor slab.
A separate reinforced concrete structure of basically the same outline as the floor slab and destined to become the roof, is constructed on the floor slab with the aid of a shaping and smoothing screed mounted on the column to rotate about a vertical axis. This latter structure is elevated by means of lifting devices temporarily mounted on the top of the column.
With the roof thus suspended, additional concrete is poured into a form that has been placed around and outwardly displaced from the column. The result is the format on of an expanded column that defines an upwardly facing peripheral shoulder on which the roof rests when the lifting force is removed. The screed is designed to be of variable length, e.g. by a hinged or telescopic end, to enable two such buildings to be constructed contiguously without the screed from one interfering with the other. A ceiling layer, including insulation, can be laid on the floor slab when the roof structure is being poured so as to be bounded thereto and thus provide a preformed ceiling when the roof is hoisted into place.

Description

11~5~83 Background of the Invention This inventlon relates to building construction and includes a method thereof and apparatus therefor.
In my prior Canadian patent ~o. g42,525 issued February 26, 1974 (UrS~ patent No, 3,798,868 issued March 26, 1974) there is described a building method in which a floor slab of reinforced concrete is first laid down, and then a reinforced concrete roof structure is constructed on the floor slab, i.e.
using the floor slab as a base with a polyethylene sheet placed over it to keep the roof structure and floor slab separate.
A centrally located gin pole or the like extending up from the floor slab acts to define a vertical axis about which a shaping and smoothing screed can be rotated to aid in the formation of both the floor slab and the roof structure. When completed, the roof structure is raised from the slab to form the roof~ In one version, the roof structure is inverted during its elevation, and is subsequently supported on a central column that had already been formed integrally with the remainder of the roof structure. In an alternative version, a centrally located, vertical column is initially mounted on the floor slab and the roof structure is elevated around such column, without inversion.
Finally, the roof structure is secured to the upper part of the column by appropriate fixing means such as metal or concrete keys. When in position, the roof structure is thus cantilevered from the central column to the perimeter of the building. This latter method is illustrated in Figs. 19 and 20 of my said prlor patent.
Summary of the Invention The present invention is related to improvements in this latter method and to improvements in the resulting structures. It also relates to improvements in apparatus for

- 2 -11~5583 carrying out such a construction method:
As was also explained in my prior patent, the general method is applicable to the construction of buildings of various shapes in plan view. The main examples given in the prior patent were of circular bulidings.
In the present invention, the same versatility exists.
While the examples illustrated and discussed below show the construction of a square bullding, the invention is not limited thereto and extends to other shapes such as circular, rectangular and hexagonal. In the case of a rectangular shape, since the method relies essentially on a gin pole or similar structure defining an approximately central vertical axis, the larger the ratio between the major and minor dimensions, the less practicable it becomes to cons~ruct a single structure by the present method.
For example, the present method can readily be used to construct a unitary building having a length of 12 meters and a width of 10 meters. On the other hand, if a building 25 by 10 meters is required to be constructed by the present method, it becomes appropriate to build two 12~ by 10 meter structures end-to-end.
Another important consideration in selection of the building size is, of course, the fact that the roof is eantilevered outwardly from the central column, and there are practical limits to the length of a cantilever overhang that can be adopted while still maintaining an economical use of materials (concrete and steel) in the roof structure.
One object of the present invention is to provide an improved method of securely mounting the roof structure in its elevated position on the column, namely a method that is safe and economical to construct.

In this aspect, the invention can be defined as a method of building construction comprising (a) forming a vertically extending reinforced concrete column on a foundation, said column defining a vertical axis; (b) forming around said column a flat, horizontal floor slab of reinforced concrete, including shaping and smoothing the upper surface of said slab with a screed connected to said column to rotate about said axis; (c) placing on the formed floor slab and around the base of the column sheet material to prevent further concrete from bonding with said slab and base; (d) erecting a framework of reinforce-ment on such sheet material; (e) pouring further concrete onto such material around the column to embed said reinforcement and form a separate reinforced concrete structure, including shaping and smoothing the upper surface of said structure with a further screed connected to said column to rotate about said axis; (f) mounting lifting means on said column and employing said lifting means to apply an elevating force to said structure to raise it along said column from the floor slab to constitute a roof structure; (g) erecting a form around and outwardly displaced from the column to define a space between the form and the column below the elevated roof structure; (h) pouring concrete into said space to form an expanded column portion having an upwardly facing peripheral shoulder; and (i) releasing said roof structure to rest on said shoulder.
Preferably, the roof structure is initially formed with one or more conduits extending vertically through it near the column, the step of expanding the column consisting of erecting a form around and outwardly ~145S83 displaced from the column and pouring concrete through such conduits into the space between such form and the column.
Another aspect of the present invention relates to the preforming of a ceiling layer (including insulation, for example) on the underside of the roof structure while it is being constructed on the floor slab. After hoisting into position, the ceiling is in place and much inconvenient labour is avoided.
Thus, in this aspect the invention can be defined as a method of building construction comprising (a) forming a flat floor slab with a generally centrally located, vertically extending reinforced concrete column; (b) placing a ceiling layer on said floor slab around said column; (c) constructing a separate reinforced concrete structure on and bonded to said ceiling layer; (d) applying an elevating force to said structure to raise it along said column from the floor slab to constitute a roof structure having the preformed ceiling layer secured to the underside thereof; and (e) securing said roof structure to an upper part of the column.
Other features of the invention will become apparent from the following description.
Brief Description of the Drawings Embodiments of the invention are illustrated in the accompanying drawings in which:
Fig. 1 is a perspective view of a building site at a preliminary stage;
Fig. 2 corresponds to Fig. 1, while showing formation of the floor slab;
Fig. 3 is a vertical cross-section of Fig. 2;

11~5583 Fig. 4 is a central portion of Fig. 3 on an enlarged scale;
Fig. 5 is a view correspon~ing to Fig. 2, showing formation of the roof structure;
Fig. 6 is a vertical cross-section of Fig. 5;
Fig. 7 is a section on VII-VII in Fig. 6;
Fig. 8 is a perspective view of the roof elevating operation;
Fig. 9 is a fragmentary vertical section of this operation showing the formation on an enlarged central column;

- 5a -11~55k~3 Pig, 10 is a section on X-X in Fig. 9;
Fig. 11 is an enlarged view showing a detail of Fig. 9;
Fig. 12 is a cut away perspective view of the overall construction, showing the enlarged central column;
Fig. 13 is a fragmentary vertical section showing a modification in the formation of the roof structure;
Fig. 14 is a diagram in plan view demonstrating the manner of operation of an expansible screed;
Fig. 15 is a perspective fragmentary view of an expansible screed;
Fig. 16 is a fragmentary side view of a tilting screed end;
Fig. 17 corresponds to Fig, 16, while showing the screed end in a different position, and Fig. 18 is a perspective view demonstrating use of the screed of Figs. 16 and 17.
Description of Preferred Embodiments . . _ Figs. 1 to 4 show the construction of the floor slab.
The perimeter of a square site, for example 10 meters square, is defined by a form 10 that projects above a gravel or other suitable bed 11. Centrally of the site there is a square cavity 12 and peripherally an elongated ditch 13. The floor slab is formed in two stages. In the first stage, there is constructed a central assembly 14 (Figs. 1 and 4) which consists of a square concrete footing 15 located above the central cavity 12 and a square column 16 that is formed integrally with and projects vertically upwardly from the footing 15. This column 16 is constructed in a conventional manner by means of a form (not shown) and conventional reinforcing rods 17 are embedded in this assembly. A metal cap 18 is placed on the 11~5583 top of thc colwnn 16, such cap having an upwardly projecting cylindrical portion 19 that acts as a gin pole to pivotally support arms 20 of a scrced 21 (Figs. 2 and 3). A collar l9a (Fig. 3) adjustable along the portion 19 acts to support the screed 21 vertically. A circular track 22 is secured to a lower part of the column 16 to cooperate with a roller 23 secured to the screed 21.
The second stage in the formation of the floor slab is then carried out, namely the pourin~ of further concrete to fill in the peripheral and intermediate areas between the footing 15 and the form 10. Conventional reinforcing rods 24 are again embedded in the concrete. The upper surface of the concrete is smoothed by use of the screed 21 which is rotated by hand about the gin pole 19 and track 22 while resting on the collar l9a and near its end on the form 10.
Hence a flat, horizontal floor slab 25 is formed. Figs. 2 and 3 show a horizontal hinge 26 between an end 21a of the screed 21 and the remainder thereof, which hinge can be used to obtain a variable slope, for example in the corners, by allowing the end 21a to tilt upwardly as will be more fully explained below. However, in normal operation, the end 21a will be firmly fi~ed to the remainder of the screed by bolts (not shown) so as to provide a continuous flat surface.
The screed 21, including its end 21a, carries a replaceable wooden lower edge member 27 for engagement with the concrete.
It will be appreciated that the size and shape of the foundations beneath the floor slab 25 can vary as re~uired by the soil and other conditions and that thc shape, thick-ness and reinforcement of the floor slab itself can also vary~ the illustrations in Figs. 1 to 4 merely providing one cxamplc.

~14SS83 ~- Once thc floor slab has harderled the form 10 is raiscd at 10a (Figs. 5 and 6) to define the perimeter of a similarly shapcd cavity in which thc roof assembly will now bc ~ormccl. A pol~ethylelle sheet 30 or other bond break material is placed on the upper surface of the floor slab 25 to prevent the concrete of the roof assembly from joining with that of the floor slab. Likewise, similar sheets 31 are placed around the lower end of the column 16. The desired pattern of reinforcing rods 32 for embedding in the roof structure is then laid down.
Since this pattern of reinforcement can take many and varied forms depending upon the size of the building and the loads for which it has been designed, and since the particular pattern chosen is unimportant to the present invention, the rods 32 shown are only intended to be symbolic of the existence of reinforcement.
Once this reinforcement has been put in place, a second screed 33 is mounted on the gin pole 19 and track 22.
The bottom edge 34 of this second screed slopes downwardly from the centre towards its end remote from the column 16, whic.
end rests on the form 10a. A body of low slump concrete is then poured onto the sheet 30 and smoothed into the desired shape by manual rotation of the screed 33 around the gin pole 19 to form the roof structure 35.
Fig. 7 is a section showing how the track 22 is mounted on the column 16 by means of expansible clamps 36 to provide a secure support for the roller 23 and hence the screed 33.
Fig. 6 shows a section ta~en with thc screed in the position of ~ig. 5, i.e. touching the form 10a at 38, and with a portion 33b of thc screcd end 33a projecting beyond the ~orm 10a. T}lis extra lenc3th is required ~hen the screed is rotated so as to extend to a corner, an~ indeed the total screed length will be chosen to enable the screed end just to rest on the form lOa at a corner point 39 that is furthest from the axis defined by the pole 19 and track 22. In order that rotation of the screed from point 38 to point 39 should not involve elevation of the main bulk thereof, the projecting screed portion 33b has a horizontal bottom surface 33c in contrast to the bottom surface 33d of the remainder of the screed which slopes downwardly and outwardly. It follows that point 40 on the screed bottom surface, which point engages point 38 on the form lOa in the position of Figs. 5 and 6, is at the same level as point 41 which engages point 39 on form lOa when the screed extends to a corner.
As a result the levels of other parts of the screed, such as points 42 and 43 (Fig. 6), remain constant during rotation of the screed.
The upper surface of the roof structure 35 is thus given a shape consisting essentially of a frusto-conical main part with flat corners. However, as will be explained below, ~0 this shape can ke varied samewhat to meet special requirements.
Figs. ~ to 11 shGw how the roof structure 35, once the concrete has thoroughly hardened, is lifted from the floor slab 25 by means of cables 50 operated by jacks 51 or other known lifting devices. The jacks 51 are mounted near the ends of a pair of cross-beams 52 that have been positioned on top of the column 16 to replace the cap 18. This cap and its associated pole 19 are no longer needed, since the screed 33 was removed once the concrete had been smoothed and hardened.
The cables 50 are temporarily secured by screw fixings 53 (Fig. 11) to rods 54 secured to plates 55. These rods and plates had been implanted in the concrete of the roof structure 11455~3 35 prior to the concrete pouring operation in a removable manner so that ~hey can be reused.
With the roof structure 35 thus held high, a form 60 (Flgs. 9 and 10) is set up around and spaced outwardly from the column 16, and further concrete piped into the space between this form and the column, This additional concrete is introduced through four metal tubes 61 that were embedded in the roof structure 35 during it formation. When this further concrete has thoroughly hardened and the form 60 has been removed, the result is the formation of an enlarged column 16a, as shown in Fig. 12. This enlarged colunm 16a provides an upwardly facing peripheral shoulder 62 extending around the column, onto which the roof structure 35 can then be lowered by relaxing the elevating forces of the jacks. The jacks and cables are then removed and all holes in the roof structure suitable plugged.
Subsequently, insulation and waterproofing materials can be placed above and/or below the basic roof structure constructed by the foregoing method. The external wall structure of the building (suggested by the broken lines 63 in Fig. 12) will then be erected. Such wall structure will normally consist of a series of panels each mounted to extend between the perimeter of the floor slab 25 and the corresponding perimeter portion of the roof structure 35 Such panels will not be required to support any of the weight of the roof which is entirely cantilevered from the central column 16a.
The equipment used, e.g. the screeds, forms, polyethylene sheets, cables, jacks and associated parts can be reused in the construction of the next builiding-Fig. 13 shows a modification to the step of forming the roof structure. With the polyethylene sheet 30 in place 55~33 ~:` on thc floor slab 25, a ceiling layer 64 of insulation and/or other matcrial required towards the formation of the ultimate ceiling o~ the buildin~ is laid down prior to the rcinforce-ment rods (not shown in ~ig. 13) and hence prior to pouring of the concrete that ultimately forms the roof structure 35. If the layer 64 is such as to effectively separate the concrete slabs 25, 35, the shcet 30 can be dispensed with. Suitable ties 65 are provided to become embedded in the concrete. As a result, when the roof structure 35 is formed and elevated, part or all of the ceiling layer is already in place on the underside thereof. This saves a considerable amount of awkward and time-consuming labour when the building is being finished.
It is to be understood that the layer 64 shown in Fig. 13, which consists of insulation material supported on a metallic framework, is purely exemplary of the concept of providing the concrete roof structure with an underside while the roof structure is on the floor slab. Such preforned underside ceiling layer can include other features such as conduits for electric lighting, panels or other finished surfaces. The concept may thus be defined as providing a partially or completely finished "ceiling" on the underside of the roof structure while it is being constructed on the floor slab prior to elevation.
As mentioned above, when a large building is required, it will be convenient to construct two or more buildings of the type already described side-by-side or end-to-end.
Fig. 14 shows two contiguous floor slabs 25a and 25b for a pair of such buildings. The screed 33 shown in this view for the formation of roof structures on the respective floor slabs should ideally be long enough to reach to the corners 39 55~33 ~; but short enough when resting at point 38 not to project into the arca over the second floor slab 25b, since, even with a - horizontal bottom surface 33c on the screed end 33b, such surface 33c would foul the roof structure 35 of the adjacent building because of the upward slope of such roof structure.
To avoid this problem, the modification shown in Fig. 15 pro-vides a telescopic arrangement of screed parts 33e, 33f and 33g to constitute the screed end 33a. A bottom edge 33h is formed from strips that can slide alongside each other to accommodate the ~elescopic action. The manner in which these parts can be compressed and expanded at will to avoid the screed extending into the area of an adjacent building will be clear from Fig. 14.
Alternatively, this problem of avoidance of inter-ference between adjacent constructions can be solved by pivoting the screed end, instead of, or as well as, making such end telescopic.
Figs. 16 to 18 demonstrate how the hinging of the ~ screed end 33a can be utilised to form a roof structure 35a having an upper surface consisting of a series of undulations.
Such a roof surface may be useful to facilitate drainage of rain water and to channel such rain water into specific locations for subsequent collection. Obviously other variations of the surface contours of the roof structure are also made possible by this method. A plate 40 bridges the gap in the working edge 34 caused by pivoting about the hinge 37.

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A method of building construction comprising:
(a) forming a vertically extending reinforced concrete column on a foundation, said column defining a vertical axis;
(b) forming around said column a flat, horizontal floor slab of reinforced concrete, including shaping and smoothing the upper surface of said slab with a screed connected to said column to rotate about said axis;
(c) placing on the formed floor slab and around the base of the column sheet material to prevent further concrete from bonding with said slab and base;
(d) erecting a framework of reinforcement on such sheet material;
(e) pouring further concrete onto such material around the column to embed said reinforcement and form a separate reinforced concrete structure, including shaping and smoothing the upper surface of said structure with a further screed connected to said column to rotate about said axis;
(f) mounting lifting means on said column and employing said lifting means to apply an elevating force to said structure to raise it along said column from the floor slab to constitute a roof structure;
(g) erecting a form around and outwardly displaced from the column to define a space between the form and the column below the elevated roof structure;
(h) pouring concrete into said space to form an expanded column portion having an upwardly facing peripheral shoulder; and (i) releasing said roof structure to rest on said shoulder.

2. A method according to Claim 1, wherein (j) said separate reinforced concrete structure is constructed with at least one conduit extending vertically therethrough adjacent the column, and (k) said pouring of concrete to form the expanded column comprises pouring said concrete through said at least one conduit.

3. A method according to Claim 1 including the steps of placing a ceiling layer on said floor slab and bonding said ceiling layer to the concrete poured to form the separate reinforced concrete structure that becomes the roof structure whereby to furnish the underside of the elevated roof structure with a preformed ceiling layer.

4. A method according to Claim 3, wherein said ceiling layer includes a layer of insulating material.

5. A method of building construction comprising (a) forming a flat floor slab with a generally centrally located, vertically extending reinforced concrete column;
(b) placing a ceiling layer on said floor slab around said column;
(c) constructing a separate reinforced concrete structure on and bonded to said ceiling layer;
(d) applying an elevating force to said structure to raise it along said column from the floor slab to constitute a roof structure having the preformed ceiling layer secured to the underside thereof; and (e) securing said roof structure to an upper part of the column.

6. A method according to claim 5, wherein said ceiling layer includes a layer of insulating material.

7. A method according to Claim 5, wherein said step of securing the roof structure to the upper part of the column comprises, (f) forming additional concrete around the column below the elevated roof structure to expand the column laterally and form an upwardly facing peripheral shoulder thereon; and (g) releasing the elevating force to allow the roof structure to rest on said shoulder.