SKAARBERG PETTER (NO)
STENSRUD TROND (NO)
SKAARBERG PETTER (NO)
| WO2000032889A1 | 2000-06-08 |
| US5268226A | 1993-12-07 | |||
| EP2050885A2 | 2009-04-22 | |||
| DE19542315A1 | 1997-04-24 | |||
| GB2261234A | 1993-05-12 |
| P a t e n t c l a i m s 1. A constructional element (1) of super light concrete, comprising at least 50 % by vol- s ume expanded plastic material, the element is substantially slab-formed having a first and second side surface at a predetermined distance (a + b) from one another constituting the thickness of the element, c h a r a c t e r i z e d i n that the density of the super light concrete is varied in the direction of the element along the thickness thereof. 0 2. A constructional element according to the claim 1, w h e r e i n the element comprises more layers (2, 3) with different densities. s 3. A constructional element according to the claim 2, w h e r e i n the element has a first layer (2) with relatively higher density and a second layer (3) with a relatively lower density. 0 4. A constructional element according to the claim 3, w h e r e i n the first layer comprises a mesh reinforcement (5). 5. 5 A constructional element according to the claims 3 or 4, w h e r e i n the first layer (2) is having a density in the range of 350 to 500 kg/m3, preferentially approximate 400 kg/m3, and a thickness in the range of 8 to 12 cm, preferentially approximate 10 cm, whereas the second layer (3) is having a density of in the range of 50 to 80 kg/m3, preferentially approximate 70 kg/m3, and is having a thickness in the range0 of 12 to 20 cm, preferentially approximate 15 cm. 6. A constructional element according to the claims 3, 4 or 5, c o m p r i s i n g a third layer (6) with the relatively higher density, the second layer (3) being5 situated between the first (2) and the third (6) layer. 7. A constructional element according to any of the preceding claims 3 to 6, w h e r e i n the layers (2, 3, 6) are floating into one another, whereby the constructional element constitutes a substantial monolithic unit. 8. A constructional element according to any of the preceding claims 3 to 7, c o m p r i s i n g a layer of plaster (7, 8) at least on one of the side surfaces, 9. A method for the manufacture of a slab-formed constructional element (1), comprising super light concrete having at least 50 % by volume expanded plastic material, the constructional element (1) being casted in a horizontal mould, c h a r a c t e r i z e d i n that a first layer (2) of super light concrete with a rela- tively higher density is casted in the bottom of the mould, preferentially with a mesh reinforcement, whereupon a second layer (3) of super light concrete with relatively lower density is casted on the first layer (2), preferentially before the first layer is set, and in that a possible third layer (6) with a relatively higher density is casted op the second layer (3). 10. A method according to the claim 9, w h e r e i n a completed constructional element (1) after the demoulding is provided with a layer of plaster (7, 8) at one or both sides. |
The present invention relates to a constructional element made from super light concrete, including expanded plastic materials in a portion of at least 50 % by volume. Such concrete has also been denoted polyconcrete due to the plastic material is often consisting of expanded polystyrene.
Such constructional elements are used to manufacture complete buildings of polyconcrete, e.g. as disclosed by NO-B 322390, and can be produced as discussed by NO-A 20070758.
For supporting external wall of polyconcrete, it has been utilized a wall thickness of 25 cm and a density of 250 kg/m 3 to provide for sufficient supporting capacity, while the coefficient of thermal conductivity has been small enough to comply current regula- tions. However, new regulations for frame work walls having a thickness of 25 cm, in which the coefficient of thermal conductivity has to be lower than achievable by the previous external walls of polyconcrete. Accordingly, the present invention is to solve the problem of providing a supporting wall of polyconcrete which is able to comply with the lower coefficient of thermal conductivity without an increased wall thickness.
The problem of the invention is solved by a constructional element as specified by claim 1. Favourable embodiments of the invention are specified by the dependent claims 2 to 8. The invention is also relating to a method as specified by claim 9, with a favourable embodiment as specified by claim 10.
For a better understanding of the invention, it shall be further described with reference to the embodiment examples shown in the accompanying drawing, in which:
figure 1 shows in cross-section a first embodiment of a wall element according to the invention; and
figure 2 shows a section similar to figure 1 through another wall element according to the invention.
The constructional element 1 being illustrated in figure 1, can be intended for use as an external wall in a building of polyconcrete. The element is having a first layer 2 with thickness a, and a second layer 3 with thickness b. The first layer 2 has a density in the range of 350 to 500 kg/m 3 , preferentially approximate 400 kg/m 3 , whereas the second 3 has a density in the range of 50 to 80 kg/m 3 , preferentially about 70 kg/m 3 . The first layer 2 can have a thickness a in the range of 8 to 12 cm, preferentially approximate 10 cm, whereas the second layer 3 can have a thickness b in the range of 12 to 20 cm, pref- erentially about 15 cm. Herein, the first layer 2 is forming the supporting portion of the element, whereas the second layer 3 is mainly having an insulating function.
The partition 4 between the two layers is specified by a broken line to indicate that no clear partition is needed between the layers but these can be intermeshed as to form an approximate monolithic unit. Figure 1 is also illustrating that the first layer 2 is provided with a mesh reinforcement 5, preferentially arranged in a manner passing through the centre of gravity for the constructional element (not shown). The mesh reinforcement 5 can be suitable form an anchoring for lifting hooks as also being illustrated by NO-A 20070758.
It will be understood that the constructional element 1 shown in figure 1 can also be used as a floor element, in which the first layer forms a lower side of the element. In this case, the reinforcement 5 can be situated closer to an external side of the layer 2. If the element is used as an external wall, it can appropriately be provided with a layer of plaster at the external surface, possibly also at the internal surface, and some form of vapour barrier will also be arranged at an internal surface of the element. Favourably, the layers of plaster can be situated in connection with the process of manufacturing the element.
In the embodiment example from figure 2, the element 1 has a third layer 6 also having a relatively higher density the intermediate layer 3. Further, the element is provided with layers 7 and 8 of plaster of which one can be combined with a vapour barrier. An element of this type can be suitable as an internal supporting wall. The absolute mutual thickness of the layer 2, 3 and 6 can be varied according to the actual conditions of use. Of course, and when appropriate, the element can be provided with a mesh reinforcement.
According to the invention, production of the constructional element will normally occur by casting within a substantial horizontal mould having a width adapted to the wanted ceiling height. If a mesh reinforcement 5 is to be used, this is situated at a bottom of the mould on distance to enable correct positioning of the mesh within the completed element. Thereafter, the first layer 2 with larger density is casted in correct height, whereafter the second layer 3 with lower density is casted, preferentially before the first layer 2 has been able to harden, whereby some mixing of the two layers is effected in the transition zone. If the element is to have a third layer 6, this is casted as soon as the second layer 3 is sufficiently hardened to support the third layer 6. After adequate setting of the layers, the element is demoulded and, possibly, provided with layers 7 and 8, before it is put aside for further cure of the components.
The super light concrete will usually utilize expanded polystyrene as the insulating material and will include a wetting agent in order to make the cement to adhere to the poly- styrene spheres which can originate from both fresh and recirculated polystyrene. The cement can be a Portland cement, gypsum-based cement or another suitable binding agent.