WO1996022431A1

WO1996022431A1 - Mould and blank

Info

Publication number: WO1996022431A1
Application number: PCT/SE1995/001292
Authority: WO
Inventors: Christer Elander
Original assignee: Kroken I Mo Aktiebolag
Priority date: 1995-01-17
Filing date: 1995-11-01
Publication date: 1996-07-25
Also published as: AU4274596A; SE503830C2; SE9500126D0; SE9500126L

Abstract

A mould for casting in situ pillars, columns, posts and like vertical objects from preferably reinforced concrete, wherein the mould is produced from one or more sheets (2) of corrugated paperboard or some other type of paperboard, plastic, or a composite material which includes at least one of the materials, and wherein the sheet is folded to the shape of a vertical tube (1) of polygonal horizontal cross-section, the tube being reinforced externally by a plurality of circumferentially extending reinforcement collars (11, 11'). The reinforcement collars include a horizontal frame (12, 12') or brim which embraces the tube (1), and a vertical part (13, 14; 13', 14') which extends along at least one side (4A, 4B) of the tube in abutment with said side and extends up to an adjacent reinforcement collar with which it is connected, wherein said part functions to reinforce said side and to form spacer means between the reinforcement collars at the same time.

Description

MOULD AND BLANK

TECHNICAL FIELD

The invention relates to a mould for casting in situ pillars, columns, posts and like vertical objects, preferably from reinforced concrete, said mould being constructed of one or more sheets of corrugated paperboard or some other type of paperboard, or alternatively from plastic or from a composite material comprising at least one of said materials, said sheet being folded to the shape of a vertical tube of polygonal horizontal cross-section and the tube being strengthened externally by a plurality of circumferentially extending reinforcement collars. The invention also relates to a reinforcement-collar blank.

DESCRIPTION OF THE BACKGROUND ART

Pillars, columns, posts and like vertical reinforced-concrete structural elements are used to a very large extent as load-bearing elements between the stories or floors of modern buildings. The mould, or form, is traditionally produced from wood in situ, i.e. on the building site. This traditional technique affords two substantial advantages which make the technique still predominant in the art, if not supreme at least when moulding or casting relatively tall pillars and like structural elements: The moulds can be made very strong and are constructed around prepared reinforcement in situ. However, this traditional technique also has a number of serious drawbacks: Wood is expensive, the joinery involved in constructing the moulds takes a relatively long time to accomplish, and stripping of the moulds when moulding of the element is complete takes even longer time.

Moulds of the kind defined in the introduction are used also to mould smaller objects. More specifically, moulds constructed from paraffinized corrugated paperboard are used to mould foundation columns and like structural elements to a height of up to about 1 m. At present, however, moulds of this kind cannot be used for moulding pillars and other relatively long post-like objects. This is due to the static pressure that is exerted by the liquid cement on the mould. The problem is accentuated when the liquid mass is vibrated. The risk of the mould rupturing is already prevalent when moulding foundation columns that measure 20 x 20 cm in cross-section, when the column height exceeds about 1 m. The taller the object to be moulded, the greater the problems; in particular, the stresses that prevail in the lower part of the mould will be very high due to the static pressure exerted against the mould walls.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a mould which, similar to the traditional wooden mould, can be constructed in situ and built-up around a prepared reinforcement and which has a strength that will permit relatively high or tall pillars, columns and like vertical objects to be moulded, but which is much cheaper than the wooden mould, partly because the material from which the mould is constructed is cheaper than wood and partly because both erection and stripping of the mould can be achieved more quickly. In the present context, "substantial height", refers to heights in excess of 2 metres, preferably heights of the order of 3 m. One particular advantage afforded by the use of moulds constructed from paraffinized corrugated paperboard is that the material is very light in weight and can be destroyed by burning after use.

These and other advantages afforded by the invention are achievable with a mould of the kind defined in the preamble and having the characteristic features set forth in the charac- terizing clause of the appending Claim 1.

Other characteristic features and aspects of the invention and other advantages afforded thereby will be apparent from the dependent Claims and from the following description of a preferred embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS

A preferred exemplifying embodiment of the invention will now be described with reference to the accompanying drawings, in which

Fig. 1 is a side view of a mould according to the preferred embodiment of the invention; Fig. 2 is a top view II-II in Fig. 1 in larger scale; Fig. 3 is a bottom view III-III in Fig. 1 in the same scale as that in Fig. 2;

Fig. 4 is a perspective view of a cardboard blank used for producing a tube which determines the shape of the moulded product; Fig. 5 is a perspective view of the upper side of a first blank for upper reinforcement collars;

Fig. 6 is a perspective view of a second blank for lower reinforcement collars;

Fig. 7 is a perspective view of upper reinforcement collars mounted on said tube;

Fig. 8 is a view taken on the line VIII- VIII in Figs. 5 and 6 showing said first and second blanks respectively in larger scale; Fig. 9 illustrates the same part as that shown in Fig. 8. when the reinforcement collars are ready to be mounted on the tube; Fig. 10 is a view taken on the line X-X in Fig. 1 and illustrates the manner in which a reinforcement flap on an upper reinforcement collar is anchored in an overlying reinforcement collar mounted on the tube; and Fig. 1 1 is a view taken on the line XI-XI in Fig. 1 illustrating the anchorage of a reinforcement flap on a lower reinforcement collar.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Referring first to Fig. 1, there is shown a tube generally 'referenced 1. The tube is constructed from the blank 2 shown in Fig. 4, said blank being comprised of a rectangular sheet of corrugated paperboard that has been paraffinized completely throughout. The sheet is provided along its length with recessed folding lines 3 that extend along the full length of the blank 2 parallel with the corrugations of the fluted layers and which are so positioned and so mutually spaced as to enable the blank to be folded along the fold lines 3 to form said tube 1. The side of the blank 2 visible in Fig. 4 forms the inside of the tube 1.

The tube 1 has a polygonal cross-sectional shape, more specifically an octagonal cross- sectional shape. The cross-sectional shape of the tube can be described as "quadratic with bevelled corners". More specifically, the tube 1 has four "broad sides" 4A; 4B, 4C and 4D of mutually equal size alternated with four corner sides 5. In the illustrated case, the tube 1 has a total width of about 320 mm and a total parameter of about 1600 mm. From the aspect of mechanical strength, it would be desirable for the tube 1 to comprise at least two layers of corrugated paperboard, i.e. that the blank 2 is wound through two or more turns. However, this would require the blank to be very wide. Impregnated corrugated paperboard of such large widths are not found in standard sizes. The manufacture of impregnated corrugated paperboard in such widths would therefore be highly expensive. Accordingly, there is used in accordance with the preferred embodiment a blank 2 which forms a tube 1 which extends along the full length of the form and which is wound a little less than approximately one and a half turns. More specifically, the tube 1 of the illustrated embodiment has been wound so as to have a double-walled thickness in the region of one broad side 4D and in the region of half of the broad side 4C and the intermediate comer side. The remaining two broad sides 4A and 4B of the tube 1 are thus single-walled. Fig. 2.

The mould is reinforced at its lower part with a further layer of corrugated paperboard 6. which is wound around the tube 1 to a height of 0.5 m from the bottom edge of said tube. Figs. 1 and 3. The blank from which the corrugated-paperboard layer 6 is formed is also comprised of a paraffin-saturated sheet of corrugated paperboard provided with recessed fold lines principly in the same manner as the blank 2. The blank forming the layer 6 has a length of 50cm and a width sufficient for the blank to be wound around the tube 1 through a little more than one turn.

Fig. 5 illustrates a first blank 10 from which upper reinforcement collars 1 1 that are intended for the main part of the tube 1 are configured, i.e. that part of the tube which extends from the top edge of the tube down to the extra layer 6 of corrugated paperboard. The blank 10 is comprised of a sheet of paraffin-impregnated corrugated paperboard of the same kind as that used for the blank 2. The blank 10 has the form of a circumferentially extending, flat frame 12 and a pair of flaps 13, 14 which are hinged at 15, Figs. 8 and 9, to a respective inner edge of the frame 12. The hinges 15 are created by providing the blank 10 with hobbed fold lines 16 at respective frame edges. When the flaps 13 and 14 are lifted up, there is formed within the frame 12 a cavity whose contours coincide with the outer contour of the tube 1. The distance in h between the centre line of the fold line 16 and the inner/upper edge 18 of respective flaps 13, 14 corresponds with the desired distance h between the (in this embodiment) seventeen upper reinforcement collars 11 that embrace the tube 1. In the region of the fold line 16, there is provided in the region of each flap 13, 14 an aperture 20 which extends along the fold line. In the case of the illustrated embodiment, this aperture has a width of 15 mm when the reinforcement collar 11 has a thickness of 7 mm. The aperture 20 is also so orientated in relation to the fold line 16 that when the flap 13/14 is lifted up, the flap will extend two millimeters above the frame 12, as indicated in Fig. 9. The width b of the aperture 20 will herewith be reduced horizontally to about 5 mm when the dimensions are those aforesaid. The height of the thus deformed aperture or slot 20, Fig. 9, is referenced in s and has a length of about 12 mm in the case of the illustrated embodiment. When the reinforcement collar 1 1 is fitted on the tube 1 , there is thus formed between the flap 12 and the tube 1 a slot 20' that has a width of about 5 mm, Fig. 10. The slot 20A is able to receive a lip 21 which projects out beyond the edge 18 of the flaps 13, 14. The lip 21 has the same length as the slot 20 and a height which is only just short of the length s.

Bottom reinforcement collars 11', which are seven in number and embrace the outer corrugated-paperboard layer 6, are constructed in a corresponding manner. Fig. 6 shows a blank 10' from which one such reinforcement collar 11' is produced. The construction is analogous with the blank 10 and also with corresponding parts of the blank 10' and the collar 11', and accordingly the same reference signs have been used as those used with respect to the blank 10 and the collar 11 but with the addition of a prime. It shall be mentioned, however, that the height h' of the flaps 13' and 14' is smaller than the height h. It will also be understood that the octagonal cavity 17' is slightly larger than the cavity 17, so as to enable the collar 1 1 ' to be forced over the outer corrugated-paperboard layer 6 at the bottom part of the mould.

The mould is constructed in the following manner. The tube 1 is formed around prepared reinforcement on the building site, by folding along the fold lines 3 and fixating the tube by pinning. The extra layer 6 of corrugated paperboard is placed around the bottom part of the tube 1, and there pinned in position. The bottom reinforcement collars 11' are then threaded onto the tube 1 and over the bottom layer 6 from either direction. The collars 11 ' are herewith orientated so that the flaps 13 'and 14' will lie outside the broad sides 4 A and 4B, which as a result of the extra layer 6 of corrugated paperboard are now "double walled". The lips 21' of respective flaps 13' and 14' are now inserted into respective slots 20A', Fig. 10. At the same time as the flaps 13' and 14' function to strengthen the broad sides 4A and 4B. they also function as spacer means between the bottom reinforcement frames 1 1 '.

The seventeen upper reinforcement frames 1 1 are fitted onto the tube in a corresponding manner, wherein the flaps 13 and 14 are correspondingly caused to strengthen the single- walled broad sides 4A and 4B while functioning as spacer means between the reinforcement collars 1 1 at the same time. The lips 21 are now moved up into respective slots 20A. Because the flaps 13, 14 are slightly thicker - thickness t - than the width, width b of the slot 20A, the lips will be received in the slots with a given press fit.

The mould can be filled with fresh concrete subsequent to having fitted the mould with reinforcement collars 1 1' and 11 along the whole of its length. The concrete will exert significant static pressure, particularly after vibration. The concrete presses against the walls of the tube 1 therewith pressing the walls out towards the reinforcement collars 1 1.

1 1 ' with the result that the lips 21, 21' are clamped firmly and heavily between the tube 1 or the corrugated-paperboard layer 6 and respective frames 12, 12' in the slots 20A, 20A'.

In turn, this results in the lips 21, 21' being clamped firmly and heavily in their respective slots inwardly of the collars 12, 12'. The flaps 13, 14 and 13', 14' thereby have an extremely effective reinforcement effect on the thinnest sides of the mould.

Claims

1. A mould for casting in situ pillars, columns, posts and like vertical objects from preferably reinforced concrete, wherein the mould is produced from one or more sheets (2) of corrugated paperboard or some other type of paperboard, plastic, or a composite material which includes at least one of said materials, and wherein said sheet is folded to the shape of a vertical tube (1) of polygonal horizontal cross-section, said tube being reinforced externally by a plurality of circumferentially extending reinforcement collars (11, 11'). characterized in that the reinforcement collars include a horizontal frame (12, 12') or brim which embraces the tube (1), and a vertical part (13, 14; 13', 14') which extends along at least one side (4A, 4B) of the tube and which lies against said side and extends up to an adjacent reinforcement collar with which it is connected, said part functioning to reinforce said side and to form spacer means between the reinforcement collars at the same time.

2. A mould according to Claim 1 , characterized in that said vertical part is comprised of a flap (13, 14; 13', 14') which is connected to the frame by hinge means (15, 15') in the region of the inner edge of the frame (12, 12').

3. A mould according to Claim 1 or Claim 2, characterized in that there is provided in the transition region between the horizontal frame and said flap on the side that faces towards the tube an aperture (20, 20') in which a front edge-part (21, 21') of a corresponding flap on an adjacent reinforcement collar is anchored.

4. A mould according to Claim 3, characterized in that the aperture (20, 20') is narrower than the thickness of the front edge-part of the flap.

5. A mould according to Claim 3 or Claim 4, characterized in that said front edge-part has the form of an outwardly projecting lip (21, 21').

6. A mould according to any one of Claims 1-5, characterized in that the reinforcement flaps are disposed against tube sides that have a smaller wall thickness than remaining tube sides.

7. A mould according to any one of Claims 1-6. characterized in that the tube (1) is reinforced in the bottom part of the mould with one or more additional layers (6) that is/are preferably comprised of the same kind of material as that from which the tube (1) is made, wherein said reinforcement collars (I T) and their respective flaps are mounted against the outer reinforcement layer.

8. A reinforcement collar blank for a mould for casting in situ pillars, columns, posts and like vertical objects preferably in reinforced concrete, said mould being produced from one or more sheets (2) of corrugated paperboard or some other paperboard, plastic, or a composite material which includes at least one of said materials, wherein said one or more sheets is/are folded to the shape of a vertical tube ( 1 ) of polygonal horizontal cross-section and said tube is reinforced externally with a plurality of circumferentially extending reinforcement collars (11, 1 1'), characterized in that the blank (10, 10') includes a flat frame (12, 12') which has substantial width and includes an opening (17, 17') correspond- ing to the outer shape of the tube, and in the region of said opening has at least one flap (13. 14; 13', 14') hingedly connected to an inner edge of the frame by hinge means (15, 15').