Building system for walls, beams and similar building components.
The invention relates to a building system of the kind which is indicated in the introduction to patent claim 1.
Building systems are known in which fair-sized prefabricated sheet elements have outer and inner side walls of concrete and have a core layer of high quality insulation material, the side walls being held together th distance holders which are cast into the concrete. Such elements are usually called sandwich elements and are used for insulation walls. The elements are rather complicated to produce, are heavy and require crane equipment for transportation and mounting. The system gives relatively few joints which however are usually through-going. The variations of the system can have inner side wall elements of materials other than con¬ crete, but this often makes difficult the joining of the elements and other uniting mechanisms must be used, for example cement, something which complicates the produc¬ tion. The variations of this system can comprise prefab¬ ricated fair-sized outer and inner sheet-shaped side wall elements and sheet-shaped insulation elements which are mounted together on the spot. In addition to crane equip¬ ment being necessary here also, the joining of the ele- ments with distance holders or other elements will be complicated.
Another known building system for constructing in¬ sulation walls consists of blocks (small elements) having an outer side wall of concrete or light concrete, if de¬ sired with cavities, a core layer of high quality thermal insulation material and an inner side wall of concrete, light concrete or other material, such as plaster sheets and the like. Such blocks can be built up into an insul¬ ation wall by the use of mortar or cement in the joints, if desired the blocks can be designed with a view to dry walling. The insulation layer and also the side walls can have mortises and tenons or similar designs for control and maintenance during the mounting/walling. The joints between the blocks are however through-going, because a possible mortise and tenon system gives only lesser lateral displacements. The special design of the joints makes the blocks exposes to breakage and demand careful handling. The block side walls are held together as a rule with one or more webs in concrete, giving cold bridges in the wall. The blocks are complicated to pro- duce because concrete and insulation must be cast to¬ gether. Otherwise the blocks usually have a size and weight intended for manual handling on mounting/walling, but are nevertheless relatively heavy. In the instances where the outer side wall is of light concrete the outer side must be subsequently treated or shielded/protected in order that the wall is able to stand the stress of weather, at any rate in a Norwegian climate.
Furthermore a building system is known for insulated walls constructed with outer and inner side walls of com- pact concrete stone or brick stone, which" are built with mortar in a known manner and where high quality insulation is placed between the side walls gradually as they are built. Such a wall, usually called an insulated hollow wall, is constructed of light elements which are suited for manual handling. The insulation elements can be sub-
stantially larger than the concrete elements, something which results in fewer through joints. The side walls wil however have very many joints and the outer wall surface must be specially protected in most climates. The binders between outer and inner side walls represent weak points from the insulation point of view.
Building systems are also known where prefabricated sheet elements are erected so that they form outer and inner sides of a wall as permanent frameworks. They are then held together by distance holders and the intermed¬ iate space between the elements is poured with concrete on the spot. Reinforcement can be placed in the hollow space between the elements before the concrete is poured. This gives an unisulated wall, where the load transfer between the side walls and the surface cast concrete must occur mainly by adhesion. This can in a number of instances give unsatisfactory strength. The sheet elements are usually large and are not suitable for manual handling. The distance holders are also nor- ally complicated to mount.
In another known building system so-called frame¬ work block's of concrete are used as permanent frameworks. These blocks, which have a size and weight designed for manual handling and mounting, have normal outer and inner side walls with two or more lateral binders of concrete. The blocks can be dry built and concrete can be poured on the spot into the openings between the binders, some¬ thing which results in an uninsulated wall construction. The load transfer between the blocks and the concrete pour on the spot must occur by adhesion, which' in a number of cases gives an unsatisfactory result. The shape of the blocks makes them very exposed to breakage. For accommo¬ dation at corners, openings etc. special types of blocks must be used. This means in turn that the number of necess ary variations must be relatively high.
The main object of the invention is to create a building system which consists of a low number of dissimi¬ lar, prefabricated elements, where the individual elements are simple and cheap to produce, have a form and weight which gives little risk for breakage, have a very low weight which facilitates manual mounting, are simple and quick to mount without special knowledge or skills, at the same time as the system gives construction members which have good load transfer properties in all directions. Further it is desirable to obtain external surfaces which do not need subsequent treatment and where through-going joints are not present which can produce weaknesses in ' th insulation.
According to the invention this can be obtained by designing the building system as indicated in the characte ising portion of patent claim 1.
The side wall elements can be provided with grooves of different cross-sectional shape, but it is especially advantageous to allow them to have a five-edged form as is indicated in patent claim 2.
Furthermore it is advantageous that the side wall elements are provided with attenuation grooves or rills outside the undercut grooves, as is indicated in patent claim 3. The building system according to the main claim can be employed in two main ways. It can be utilised together with a prefabricated remote element as is indicated in patent claim 4 or in that the side wall elements are em¬ ployed as framework elements as is indicated in patent claim 8. In both instances there can be used as third main element distance holdersι.for holding opposite side wall elements anchored to each other.
In that case where the bulding system is utilised with the side wall elements as framework elements the size of the system is restricted to two dissimilar ele-
ments, namely a side wall element and distance holder. In the other alternative the core element thus comes as an additional, prefabricated element. In both cases there is thus the question of a limited number of elements whic 5 are simple to produce and which have a form and a weight which means that they are not especially exposed to break¬ age during transportation and mounting. Furthermore the system has the advantage, that it is particularly suited to easy manual mounting, the maximum weight of the element 10 being kept below ca. 10 kg.
The mounting of the elements is particularly simple and can be conducted without the use of mortar or cement and without special knowledge or skills and without special tools. As will be evident from the description 15 below the adaptation can occur very simply by the use of for example a 5 cm.-module sideways. The design of the elements provides very good cooperation between them.
The building system according to the invention is very flexible and can be used with advantage for a series 20 of building components which will be described further. The flexibility comprises also that the system permits pulling down and complete reuse, for example by adjust¬ ments or changes.
The constructions built with the system according to
25 the invention are water-tight, windt-tight and self-draini and with appropriate dimensioning of the core element, this being either prefabricated or produced on the spot, a low k-value is obtained and no cold bridges.
It should thus be clear that the building system
,0 according to the invention is especially well suited for self-construction, for small houses of concrete and for system construction.
The invention will be described further below with reference to the individual embodiments shown in the
,r drawings, where:
Fig. 1 Shows a perspective view of a portion of a side wall element designed in accordance with the invent¬ ion, fig. 2 shows a corresponding perspective view of a core element designed in accordance with the invent¬ ion, fig. 3 shows a perspective view of a distance _ holder according to the invention, fig. 4A,.4B, 4C show respectively a side view, plan view from above and perspective view of a wall pro¬ duced with the bulding system according to the invention during construction, while fig. 5 shows a plan view from above of a section of a corner of a wall designed in accordance with the in- vention.
The -side wall element (11) in fig. 1 is rectangu¬ larly sheet-shaped with parallel grooves (12) on the inner side. The grooves (12) are designed and dimensioned so as to provide space for equivalent ribs 22 on the core element 21, as is .--.shown in fig. 2. The grooves 12 have an outer portion 12a which "de" (diverges ?) inwardly form an opening gap 12b in order to pass over into an inner portio 12c which converges towards the bottom 12d of the groove. The other side of the side wall element 11, the outer side, is provided with rills 13 parallel to the grooves 12. The rills 13 serve primarily as attenuations for controlled breaking/division of the side wall element. On possible plastering of the side wall elements the attenuation rills 13 will provide increased grip for the plaster. In an unplastered condition the rills 13 contribute to give the finished building component a decorative exterior.
The side wall elements 11 are suitable made of con¬ crete. In principle however they can be made of any suit- able castable or machinable building material.
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A suitable dimensioning of the side wall elements 11 is for example 50x200x600 mm with for example a groove separation equal to the thickness of the element. It is appropriate in all cases to use a length which is a mult¬ iple of the breadth.
As will be evident from fig. 1, the side wall elemen end in the middle of a groove 12 and of a rill 13. Firstly the whole groove lies there a module in form the end of the element. For dividing up the side wall element 11 for adaptation, there can be used wedges which are struck or tension screws which are pressed down in the grooves 13.
The prefabricated core element 21 in the embodiment of fig. 2 is in the form of a rectangular sheet with par¬ allel ribs 22 across both breadth sides, that is to say outer and inner sides. The ribs 22 have an omega-shaped cross-section and in shape, dimension and distance of centre to centre are adapted so that they can be intro¬ duced into the grooves 12 with abutment along four lines something which provides necessary abutment surfaces for load transfer between the side wall element 11 and the cor element 21. That portion of the cross-section of the grooves 12 which is not occupied by the ribs 22 serves as a drainage duct for water which possibly has to come in through the joints between the side wall elements 11 on dry walling. The ribs 22 are designed with very weak coning from the ends towards the middle, that is to say the diameter of the ribs at the centre is made somewhat larger than at the ends, something which together with the abutment surfaces along only four lines results in very easy introduction of the ribs 22 into the grooves 12 en mounting. In addition this design of the ribs 22 gives an easier mould release on production of the core ele¬ ments.
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The core element 21 is suitably made of a good thermally insulating material with sufficient breaking strength for load transfer through the ribs 22.
Examples of suitable materials are polyurethane and expanded polystyrene. A core element 21 which corresponds to the example of dimensions for the side wall element 11 before, can have measurements 100x200x600 mm, with 11 ribs 22 on each side, if desired without ribs at the corners. In order to be able to divide the core element 21 with a view to adaption by bond mounting in' addition there is provided centrally high a marking rill 24. The core element 21 will usually be of a material which can be easily divided by such a rill. The most central rill of the core element 21 can be indicated with a marking, in order to simplify the placing of the core element 21 correctly on mounting. In fig. 3 there is shown a distance holder or a locking element 31. This has as a purpose to bond or lock two side wall elements 11 together, where the power trans¬ fer via the core elements is not sufficient. The distance holder 31 consists of two parallel cylindrically shaped end anchors 32 connected to a sheet-like web 33. The end anchors 32 can be hollow or designed so that they fit into the grooves 12 in the side wall elements 11, with abutment surfaces along four lines in a manner corresponding to that described for the ribs 22 of the core element.
The distance holders 31 can transfer forces and are suitably made in one piece of a material with a satis- factory tensile strength, for example of plastic or of an aluminium alloy. The web 33 "..can be folded or bent so that distance holders can be used for holding together adjacent side wall element 11 or elements 11 which are meeting at 90 for example at corners such as is shown in fig. 5.
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An embodiment of the use of the building system for an insulating wall with a prefabricated core element 21 is shown in fig. 4a-c. The wall consists of core ele¬ ments 21 with side wall elements 11 on both sides. By 5 vertical mutual displacement each of the- core elements* ribs is brought into engagement with the rooves 12 of the adjacent side wall element. This load-transferring connection between the elements will be satisfactory in a number of cases. If necessary, the connection between the side wall elements can however be reinforced by the 10 use of distance holders 31 where the web 33 is placed in the vertical joint 41 between the core elements 21 and the end anchor 32 threaded down into engagement with grooves 12 o-f the side wall elements directly outside the vertical joint. 15 In the embodiment of fig. 4a-c there are shown two fastening locations of this type for each side wall ele¬ ment, that is to say a distance holder for two side wall elements (outer and inner) .
The core elements 21 are thus mounted bonded verti- 2o cally and horizontally to the side wall elements 11, so that no through joints are formed. In this way the fin¬ ished wall construction is very water-tight. Possible water which has to force in through the joints between the side wall elements will be drained as mentioned 25 above.
In an alternative mede of use a wall can be erected as in fig. 4a-c, but with distance holders 31 of greater web length than shown so that after mounting there is an open space on a side of the core element 21 between the 30. latter and the adjacent side wall element 11. This space or layer can be poured with concrete on the spot. By virtue of the grooves 12 in the side wall elements 11 and the ribs 22 on the core elements 21, there will be a very godd load-transferring connection between this poured
layer of concrete and the side wall element and the core element. In the condrete layer which is poured on the spot, horizontal and/or vertical reinforcement can be positioned before the casting. Horizontal reinforcing rods can be mounted in the cavities or the notches 34,35 in the edges on the web 33 of the distance holders. By re¬ ducing the thickness of the core element, similar types of reinforced construction can also be used as supports over openings in walls, for example door and window open¬ ings.
The layer of concrete can be poured here without t&e use of special under framework, due to the fact that the core element 21 is placed in full thickness in the lower part and hence functions as a framework. In fig. 5 there is illustrated an embodiment of a corner solution for a wall. By the use of distance holders 31 where the web 33 is bent 90° at the end anchor 32, the side wall elements 51 and 52 are connected in the corner. Adaption of the length of the side wall element 11 at a corner can be done by division along the reduced cross-section between a groove 12 and an attenuation rill 13.
The building system according to the invention can also be used for permanent frameworking, for example supP~ orting columns and beams, and for supporting, uninsulated walls. In this instance only side wall elements 11 and distance holders 31 are used. By virtue of the grooves 12 in the side wall elements 11, the connection between the side wall elements 11, will be very good and provide good load transfer. For walls and beams it can be app¬ ropriate to use a number of distance holders 31 of excess length. These are placed diagonally in order to increase the stability of the permanent framework in the plane construction. The reinforcement can be placed horizon-
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tally and vertically and the horizontal reinforcement can be mounted on the web 33 of the distance holders as de¬ scribed above. For walls the vertical reinforcement can if desired be placed in the inner, vertical grooves 12 5 of the side wall elements.
By using side wall elements 11 as permanent frame¬ works for supporting columns, there is used the same faste ing in with distance holders 31 at the corners as describe above for the corner solution for walls, see fig. 5. 0 The building system according to the above embodi¬ ments can be modified in various ways, for example by providing the side wall elements as well as the core eleme with a mortise-tenon connection in one or two directions.