NO20220408A1

NO20220408A1 - Prefabricated concrete tank

Info

Publication number: NO20220408A1
Application number: NO20220408A
Authority: NO
Inventors: Søren Østergaard
Original assignee: A Consult Holding Group As
Priority date: 2021-04-07
Filing date: 2022-04-04
Publication date: 2022-10-10
Also published as: DK202270184A1

Description

Prefabricated concrete tank

Field of the Invention

The present invention is directed to a building system for a tank and/or a plurality of interconnected tanks. Furthermore, a method of assembling tanks from such a building system is also disclosed.

In the art it is well-known to use relatively large tanks in order to accommodate liquids of different types. In this connection it is often desirable to have a large number of independent tanks in order to store different materials or to farm for example fish either of different species or different stages of their lives. It is well known that certain species of fish are predators and as such they will eat and hunt smaller fish even of the same species. For this purpose, it is quite normal to retain fish of the same age/size in separate tanks. On the other hand it is desirable from a rational point of view to have the tanks very close to each other in order to both save areal space but also to be able to have the machinery and tools and necessary for the activities going on in the tanks and near at hand.

Generally, such tanks may be constructed using a modular system where each tank is separate and therefore the modular system must address all strength and local issues arising from the use of such a tank. The present invention, however, provides a building system where interconnected tanks are used for each other’s benefit, such that a stronger, more stable and even slimmer tank system may be provided. However the building system may also be used to construct a single tank.

The invention addresses this by providing a building system for a tank and/or a plurality of inter-connected tanks, particularly suited for containing a liquid, where said tank and/or plurality of inter-connected tanks comprises a peripheral wall assembled from a number of standard panels, and a bottom, characterized in that the building system comprises:

- a plurality of plane panels;

- a plurality of connecting panels or corner panels, where said connecting panels or corner panels are provided with two or more interface edges, said interface edges suitable to be connected to the plane panels, and further that the connecting panels or corner panels are provided with either

o one or more curved channels suitable for prestressing cables, where the channels are connecting at least two interface edges; or

o Reinforcement having reinforcement eyes extending from the two or more interface edges;

and where said channels or reinforcement is designed to follow the stress paths created as the tank or tanks is/are filled with liquid.

By providing particularly the connecting panels or corner panels with the smooth transition of forces through the corners by providing that the channels or reinforcements are designed to follow the stress path created, as the tank or tanks is filled with liquid, the impact on the material from which the panels are manufactured, for example typically concrete, is severely lessened. This in turn provides less crack formation, which again improves the durability of the constructions.

It is well known when calculating a structure where stresses has to be handled as they change the direction of attack, that this will create zones where particular and often detri mental conditions occur. By designing the entire system with this in mind, and particularly the connecting panels or corner panels, it is avoided that these undesirable stress concentrations are created in the finished tanks.

In a further advantageous embodiment of the invention, the plane panels and the connecting panels or corner panels are made as pre-fabricated concrete elements. As with all pre-manufactured concrete panels, the manufacturing facilities in a well-run factory guaranties higher quality than in situ constructions, and as such by implementing the invented features of the invention into a pre-manufacturing facility, these advantages are further encouraged.

In a still further advantageous embodiment of the invention the plane panels comprise a front panel and a rear panel, which rear panel in use will be facing the contents of the tank, and where the front panel has reinforcement extending outside the concrete in use towards the rear panel, and where the rear panel has reinforcement extending outside the concrete in use towards the front panel. With this construction a number of advantages are provided. First and foremost, it is possible for the front and rear panels respectively, to be handled as single panels. As the front panel and the rear panel will have much less than half the entire weight of a finished panel, it becomes easier to handle and transport these panels and at the same time is becomes possible to transport a larger amount of panels due to the weight limitations of for example trucks. Once the front panel and the rear panel are arranged onside such that the reinforcement extending from the rear side of both panels are intermeshed, it becomes possible to fill the cavity defined by the front and rear panels respectively with in situ concrete and still obtain the advantages of premanufactured concrete panels in that the surfaces of the front and rear panels may be very smooth and precise. Additionally, particularly when the rear panel which in use will face the contents of the tank are to be exposed to for example aggressive fluids, it is possible to cast the rear panels under factory conditions with improved characteristics, for example using a more dense concrete or adding additives to the concrete mixture which makes the rear panel more suitable to the service conditions in which it will be brought. The front panel on the other hand, not being exposed to the contents of the tank, may be made from a regular often cheaper concrete, and as such also economical advantages are present with this type of construction even on the materials selection level. It is clear as will be evident below that when two or more tanks share a common wall, both panels exposed to the liquid in either tank should be provided with adequate characteristics and as such for this purpose the advantages are being able to decide on different material compositions become less pronounced but the weight saving and transport savings are still important.

In a still further advantageous embodiment of the invention, the corner panels are defined by a height, which in use will be arranged in the vertical direction limited by an upper and lower edge and a width, which in use will be arranged in the horizontal direction, where the width is limited by two panel interface edges. These corner panels are used as will be evident from the description below, in positions where that particular part of the tank is not to be interconnected with an adjacent tank. Furthermore, by providing the interface edges, it becomes easier to connect the corner panels with the plain panels and as such assure that a simple and effective connection may be facilitated by these two different panels. This is important when constructing tanks, in that in addition to being more or less impervious to the liquid which is to be stored in the tank, these connections should also be stiff and rigid in order to provide the stability of the tank even under severe load conditions.

In a further advantageous embodiment of the invention the two panels’ interface edges are arranged with an angle β relative to a vertical plane, where β is between 15º and 75º, more preferred between 20º and 50º. It is clear that as the corner panels and connecting panels are provided with a curved path for the stress obtaining elements whether the channel for pre-stressed cables or actual reinforcement, it is necessary only to have relatively shallow angles, for example in the corner panels such that no stress hot spots are created. Experiments have therefore shown that by maintaining the angle data as shallow as possible, it is possible still to manufacture/design relatively slim panels and at the same time achieve a stress distribution in the panels without creating hot spots.

In a still further advantageous embodiment of the invention the connecting panels are defined by a height, which in use will be arranged in the vertical direction limited by an upper and lower edge and a width, which in use will be arranged in the horizontal direction, where in the use position a horizontal cross-section has a general Y-shape at least with respect to the curved channels, thereby defining three panel interface edges. Like it was the case with the corner panels, the connecting panels having a general Y-shape having curved stress paths for the reinforcement, also allows for the curved paths of the tension means embedded in the concrete to be provided with relatively shallow angles between the directions in which stresses are applied to the panels and therefore the hot points where stresses are assembled may be avoided all together. By furthermore defining three interface edges it becomes possible as will be described below, to connect more tanks into a common structure thereby redistributing the forces and stresses to these surrounding structure whereby the overall stress in one particular panel is reduced.

The invention is also directed to a method of constructing a number of inter-connected tanks suitable for storing liquid, where the tanks are assembled from the building system according to any of claims 1 to 6, wherein each tank comprises a plurality of panels and a plurality of connecting panels and/or corner panels. It is clear that a method utilizing the advantages described above will also provide an inventive strong and secure array of tanks.

The invention will now be described with reference to the accompanying drawing, wherein:

Fig. 1 illustrates a building system according to the present invention;

Fig. 2 illustrates a plane view of the plurality of the interconnected tanks illustrated in fig. 1;

Fig. 3a and 3b illustrates a number of different corner panels;

Figs. 4a and 4b illustrate a number of different designs of connecting panels;

Fig. 5 illustrate a single tank, manufactured from standard panels according to the invention;

fig. 6 illustrated a front or rear panel in cross section;

In Fig. 1 is illustrated a building system according to the present invention where the building system is used for assembling a plurality of interconnected tanks 10, 12, 14, 16, 18, 20. The tanks are, as will be discussed below, suitable to hold a liquid, for example water. Each tank 10, 12, 14, 16, 18, 20 is assembled from a plurality of standard panels. The walls of the tanks are created by these standard panels where it is contemplated that the bottom is made in situ. The interface between the bottom of the panels and the bottom itself may be carried out in a number of various manners already known in the art.

The standard panels comprise plane panels 22, corner panels 24 and connecting panels 26. By using in principle three different standard panels, it is possible to erect the interconnected tank structure illustrated in Fig. 1, whereby the entire building system is standardised to such a degree that all connections, assembly details etc. are standardised which greatly reduced the chance of making mistakes, which may be detrimental to the use of the tank.

In fig.2 is illustrated a plane view of the plurality of the interconnected tanks illustrated in fig. 1, where it is clearly detectable that the tanks are assembled from a plurality of plane panels 22, corner panels 24 and connecting panels 26. It is clear that by using more plane panels 22 in the walls of the tanks, the length of the sides of each tank may be increased without departing from the principle of using standard panels.

Turning to fig.3a and 3b, a number of corner panels are illustrated. In fig. 3a four different corner panels 24, are illustrated. The variation in the corner panels is simply the curvature or design of the corner panels, but common for all the panels is the fact that they are designed to allow the wall of the tank to be continued at an angle β relative to the first part of the wall. The corner panels are furthermore provided with two interface edges 32, 34 such that when the corner panels 24 are assembled in a tank structure, the interface edges will engage and interface with corresponding interface edges provided on the plane panels 22. Between the interface edges 32, 34 are provided curved channels 36 or a fitted reinforcement 36’ where the curvature of the channels or the reinforcement 36, 36’ will follow the stress paths inside the concrete panels when tension is applied to the reinforcement. In this connection it should be mentioned that the use of channels 36 is particularly suitable for stressed concrete constructions where tension cables may be fitted through the channels, whereas the designed reinforcement 36’ specifically provided with eyes 38 extending from the interface edges is used for non-stressed or nonstressable contructions. The channels 36 may also be used for tension cables which are fitted after the erection of the tanks but before they are filled with liquid such that once the entire tank is erected it is possible to apply tension/stress to the cables in a known manner.

With reference to figs. 4a and 4b, a number of different designs of connecting panels 26 are illustrated. Common for all the various designs of the connecting panels 26 is as illustrated in fig. 4b, the provision of a channel or reinforcement 36, 36’, where the design of the channels or reinforcement 36, 36’ from interface edge to interface edge 32, 34, 40 follows the stress lanes/paths which are created when the reinforcement is activated, i.e. when the tanks are filled with a liquid or the like.

In fig. 5 is illustrated a single tank 100, manufactured from the standard panels as described above. In this embodiment two corner panels 24, 24’ are used in each corner in order to obtain a 90o angle. Between the corner panels interface edges 34, 32 in adjacent corners, are arranged a plurality of plane panels 22. In this embodiment the plane panels 22 comprises a front panel 122 and a rear panel 124. Turning briefly to fig.6, a front or rear panel is illustrated in cross section, where it may be seen that reinforcement 126 projects from a (back or rear) surface of the panel. This projecting reinforcement 126 is in addition to the normal reinforcement 128. When the plane panels are erected, the surfaces from which the reinforcement 126 extends, will be facing each other. Prior to filling the gap between the front and rear panels 122, 124, tension cables may be arranged in the void between the front and rear panels 122, 124 and the front and rear panels 122, 124 may be positioned such that the extending reinforcement 126 overlaps thereby a forming overlapping reinforcements 126 through which another vertical reinforcement bar may be inserted in order to lock the reinforcement from the front panel 122 to the rear panel 124. At this time concrete may be cast in the void between the front and rear panels 122, 124 in order to create a solid substantially monolithic structure.

Prior to casting of concrete, the tension cables may have been tensioned.

The advantage of using a construction where the plane panels are constituted by a twopart, i.e. a front panel 122 and a rear panel 124, is the fact that they actually work as lost form work and in this manner substantially reduces transportation costs, particularly if there is a substantial distance between the plant manufacturing the panels to the place where the tank is to be erected. Furthermore, in some instances it might be advantageous to use a denser concrete with rear panel in order to create a better resistance against attacks from the liquid contained in the tank where the front panel 122 may be manufactured from a lower quality concrete.

Claims

1. Building system for a tank and/or a plurality of inter-connected tanks, particularly suited for containing a liquid, where said tank and/or plurality of interconnected tanks comprises a peripheral wall assembled from a number of standard panels, and a bottom, characterized in that the building system comprises:

– a plurality of plane panels;

2. Building system according to claim 1 wherein the plane panels and the connecting panels or corner panels are made as pre-fabricated concrete elements.

3. Building system according to claim 2 wherein the plane panels comprise a front panel and a rear panel, which rear panel in use will be facing the contents of the tank, and where the front panel has reinforcement extending outside the concrete in use towards the rear panel, and where the rear panel has reinforcement extending outside the concrete in use towards the front panel.

4. Building system according to claim 1 wherein the corner panels are defined by a height, which in use will be arranged in the vertical direction limited by an upper and lower edge and a width, which in use will be arranged in the horizontal direction, where the width is limited by two panel interface edges.

5. Building system according to claim 1 or 4 wherein the two panel interface edges are arranged with an angle β relative to a vertical plane, where β is between 15º and 75º, more preferred between 20º and 50º

6. Building system according to claim 1 wherein the connecting panels are defined by a height, which in use will be arranged in the vertical direction limited by an upper and lower edge and a width, which in use will be arranged in the horizontal direction, where in the use position a horizontal cross-section has a general Y-shape at least with respect to the curved channels, thereby defining three panel interface edges.

7. Method of constructing a number of inter-connected tanks suitable for storing liquid, where the tanks are assembled from the building system according to any of claims 1 to 6, wherein each tank comprises a plurality of panels and a plurality of connecting panels and/or corner panels.

8. Method according to claim 7 wherein at least two tanks share a number of plane panels and two connection panels.

9. Method according to claim 7 wherein four inter-connected tanks share a number of plane panels and eight connection panels.

10. Method according to any of claims 7 or 9 wherein a connection between four tanks, comprises four connection panels and optionally multiple sets of four plane panels.