| WO/2008/071249 | UNIT FOR THE CONSTRUCTION OF SLAB FOUNDATIONS |
| JP62129417 | CONSTRUCTION OF FOUNDATION FOR STRUCTURE |
| JP07238557 | SITE PREFABRICATED FOUNDATION METHOD |
Hägglund, Jörgen (Sona, Hegra, N-7520, NO)
Säthre, Harald (Oberwiessestr. 108A, Jona, CH-8645, CH)
Hägglund, Jörgen (Sona, Hegra, N-7520, NO)
| 1. | Foundation for building and construction purposes, such as floors, storage areas and the like, comprising a supporting and insulating layer (17) consisting of a particle shaped material spread out on a firm or compressed ground surface (15) and covered by a cover coat (18) consisting of concrete which is hardened insitu, where at least a considerable part of the supporting and insulating layer contains a particle shaped, foamed material, characterized in that the supporting and insulating layer (17) consists, at least essentially, in polygonal particles made from a nonhygroscopic material and of a size in the range of 10 to 50 mm, which particles have essentially plane sides. |
| 2. | Foundation according to claim 1, characterized in that the supporting and insulating layer (17) has a thickness of the minimum of 150 mm, and that the cover coat (18) is made of a selflevelling concrete. |
| 3. | Foundation according to claim 1 or 2, characterized in that the supporting and insulating layer (17) consists of a minimum of 95 volume percent foamed glass particles, preferably more than 98 volume percent. |
| 4. | Foundation according to anyone of claims 13, characterized in that the supporting and insulating layer (17) is compressed to a degree of compaction of a minimum of 1,1, and a maximum of 1,25. |
| 5. | Foundation according to anyone of the claims 14, characterized in that the thickness of the cover coat (18) is in the range of 20100 mm, preferably about 40 mm. |
| 6. | Foundation according to anyone of the claims 15, characterized in that a maximum of 25 volume percent of the supporting and insulating layer (17) consists of a particulate mass with a particle size under 20 mm. |
| 7. | Method for the making of a floor or like foundations, wherein, on a ground surface, one or more supporting and insulating layers consisting of a particle formed mass having thermal insulating properties are spread out and subsequently covered by concrete for hardening insitu, characterized in that a nonhygroscopic foamed material is made having particles of a size in the range of 1050 mm as a maximum extention, in such a way that these particles have essentially plane sides, that particles of this material are spread out on a firm or compressed ground surface, the layer having a thickness of min. 150 mm, that the distributed particle material is compressed to a degree of compaction between 1,1 to 1,25, that a layer of selflevelling mass is applied on top of the distributed and compressed supporting and insulating layer. |
| 8. | Method according to claim 7, characterized in that the particles are made of foamed glass. |
| 9. | Method according to claim 8, characterized in that a part ashes and/or powdered mineral, such as stone, ceramic, porcelain, preferably under 5 %, is added to the raw material for the foamed glass. |
| 10. | Method according to claim 7 or 8, characterized in that the particles are created by natural cracking at the finishing stage of the production. |
| 11. | Method according to anyone of the claims 710, characterized in that the selflevelling mass, in the plastic state, is applied with armouring mats and/or fibre armouring, preferably made of steel fibre or glass fibre. |
The invention concerns a foundation according to the preamble of claim 1. It thus concerns a foundation for building and construction purposes, such as floors, parking lots, storage areas and the like, including a supporting and insulating layer comprising a particle shaped material spread out on a firm or compressed ground surface and covered with a cover coat comprising a plastic material which is hardened in-situ, where at least a considerable part of the supporting and insulating layer contains a particle shaped foamed material. As used herein "Ground surface" means all forms of naturally formed fields or correspondingly filled or built and compressed mass, sufficiently stable to support the building or construction to be erected.
The invention also includes a method for the construction of such a foundation.
Background
During construction of the foundation of floors, terraces, pavements and the like, it is common practice to spread out a layer of gravel on the ground surface and subsequently compress this layer before a layer of concrete is laid. The concrete, in turn, requires smoothing. This method is time consuming since it requires a lot of concrete and considerable compressing of the supporting layer. In the case that insulation is required, insulating plates can be applied. Armouring is then spread out before concrete is applied. The hardening of the concrete delays the construction of such foundations considerably.
Spreading out a layer of particles of expanded and burnt clay, which then is covered by a layer of self-levelling mass, is known in the art. It is, however, difficult with the solution to obtain satisfactory stability by compression with this solution. Compressing the mass of particles directly is difficult due to the rounded shape of the particles, and compressing the finished levelling mass is demanding due to a short setting time. This may thus lead to edge failure and unevenness of the completed foundation.
Spreading out one or more layers of gravel, as a supporting layer under insulating plates, prior to the concreting, is also known in the art. This process both takes a lot of work, and consumes a lot of materials.
Objects
The main object of the invention is to provide a foundation and a method for the construction of such, that by a small amount of work will provide for a foundation having
advantageous properties. The most important characteristics are strenght and evenness. Evenness should be acheived without the use of equipment or special efforts to level the mass, which has been the case in the prior art use of such a mass as cover coat for a supporting layer.
A further object is to reduce the consumption of mass. One should preferably be able to obtain satisfactory strenght characteristics without the use of armouring or other types of reinforcement, which would mean a greater consumption of materials and more work.
The invention
The invention is stated in claim 1. The supporting and insulating layer consists according to the invention of, at least essentially, particles of a non-hygroscopic material of a size in the range of 10 to 50 mm, which particles are polygonal with essentially plane sides.
Thus constructed, the laying of only one layer of supporting material will suffice. A small amount of compressing is required and the cover coat can be applied in a simple manner. The most important thing, however, is that a high quality foundation is acheived, regarding both mechanical strenght, stability and thermal insulating property. The pores in particles of foamed glass are closed , so that the supporting layer absorbs a minimal amount of water. Due to good insulating properties, the thickness of the supporting layer may be reduced, so that the consumption of mass and need of transportation are less than for corresponding, known foundations.
The advantageous effect of the invention regrading stability, is essentially due to the character of the particles in the supporting layer. Using polygonal particles having essentially plane sides, considerably better wedging and locking are acheived, compared to corresponding, known particles having a rounded shape, which, to a greater extent, tend to get displaced when subjected to loads.
It will be particularely advantageous if the thickness of the supporting and insulating layer is a minimum of 150 mm, and that the cover coat is made of a self-levelling concrete.
The supporting and insulating layer consists of a minimum of 95 volume percent foamed glass particles, preferably more than 98 volume percent, as stated in claim 3. The supporting and insulating layer may be compressed to a degree of compaction of a minimum of 1,1, and a maximum of 1,25.
The thickness of the cover coat is in the range of 20-100 mm, preferably about 40 mm.
The invention also includes a method for the making of a floor or like foundations, wherein, on a ground surface, one or more supporting and insulating layers consisting of a particle formed mass having thermal insulating properties are spread out and subsequently covered by concrete for hardening in-situ. A non-hygroscopic foamed material is made of particles having a size in the range of 10-50 mm as the maximum extention, in such a way that these particles have a polygonal shape and with essentially plane sides. This breaking up may be done during construction, by the disintegration of manufactured plates of foamed material by natural cracking.
A layer consisting of particles of this material and having a thickness of min. 150 mm, is spread out on a firm or compressed ground surface. The distributed particle material is then compressed to a degree of compaction of between 1,1 to 1,25. On top of the distributed and compressed supporting and insulating layer is then applied a layer of self- levelling mass.
It will be particularly advantageous if the particles are made of foamed glass, where to the raw material for this foamed material there may be added a part ashes and/or powdered mineral, such as stone, ceramic, porcelain, preferably under 5 %. The self- levelling mass may, in the plastic state, be applied with reinforcing mats and/or fibre reinforcing, preferably made of steel fibre or glass fibre.
Example
The invention will be described in more detail below, with reference to the drawings, where
Fig. 1 shows a side view of a foundation made according to prior art.
Fig. 2 shows a side view of one embodiment of the invention, and
Fig. 3 shows a perspective view of a particle suitable to be included in an foundation according to the invention.
Fig. 1 shows a foundation placed on a ground surface 11, for example a filling of compressed gravel and sand. On the ground surface is spread out a supporting and insulating layer 12 of particles consisting of expanded clay, which in turn is covered by a cover coat 13 consisting of concrete. The particles in the supporting and insulating layer are drop or ball shaped and not suited for compression, due to both shape and size. A minimal
compression may lead to failure at the edges 14 of the cover coat. In addition, they will be hygroscopic and undergo a reduction in insulating ability if they are subjected to water.
Fig. 2 shows a side view of a foundation shaped according to the invention. A separation cloth 16 is laid out on a ground surface 15, for example a fibre cloth. This will, in a manner well known in the art, prevent the intrusion of fine grained materials into the insulating layer. A supporting layer 17, containing particles of foamed glass, is spread out on top of the separation cloth 16.
Fig. 3 shows an example of such a particle. It is made of foamed glass plates split into pieces of varying size and form. The splitting is accomplished through natural cracking of the foamed glass plates coming out from known heat treatment on a conveyor belt, and falling from the conveyar belt. The pieces may be of a size in the range of 10 to 50 mm, in meaning that they are able to pass through a strainer having a mesh size of 50 mm, but not through a strainer having a mesh size smaller than 10 mm. The pores in these particles are closed and the particles are further characterized by having a rough surface, plane sides and naturally, moderately rounded edges. Rounded edges means that they are easily compressed during compacting. The plane sides means that they will tend to contact each other surface to surface, establishing firm and stable contact. The rough surfaces result in sticking together of particles in contact. The over all effect is that the supporting layer 17 is easily compressed, establishing a firmly compacted mass of particles, stable and with the ability of bearing high loads. This is essentially different from the supporting layer 12 according to the prior art foundation illustrated in Fig 1, where the particles are unable to establish firm and stable contact with each other.
The supporting and insulating layer 17 is compressed using appropriate means, for example a vibrator, a roller or a caterpillar tractor.
A cover coat 18 consisting of a self-levelling mass is applied on top of the supporting and insulating layer 17. Preferably, this may be based on cement. The use of such a mass requires no compressing or levelling.
Armouring mats and/or fibre armouring, preferably made of steel or glass fibre, may be applied to the self-levelling mass in the plastic state.
Modifications
In cases where the supporting and insulating layer 17 is laid over a larger area, the layer may optionally be covered by a thin layer of sand that will even the layer of particles and lower the consumption of levelling mass.
A diffusion-preventing foil may also be applied on top of the supporting and insulating layer, to reduce the consumption of levelling mass and to prevent the diffusion of humidity from the ground into the premises.