SE2100178A1 - Module for a load-bearing house foundation with integrated reinforcements - Google Patents

Abstract

The invention relates to a module (2) for a load-bearing foundation for a building, whereby the module (2) comprises at least three layers (4-6) where a central layer (5) consists of a heat-insulating material and at least one upper and one lower layer ( 4, 6) consist of essentially dimensionally rigid materials. The invention is achieved by load-bearing reinforcements (3) being integrated into the module (2) and where the reinforcements (3) comprise a heat-insulating material (7), for example a cellular plastic with a higher density/bearing capacity than others thermal insulation in the central layer (5) of the module (2).

Description

Module for a load-bearing house foundation with integrated reinforcements.

Field of the technology The present invention relates to a module, for a load-bearing foundation for a building, with integrated and load-spreading reinforcements.

State of the Art When building houses, the foundation must bear loads of varying size. There are two categories of loads, line loads exerted by a wall, usually wooden studs surrounded by sheet material on one or both sides. The wall carries part of the house's weight, a load that is transferred to the sill, which in turn rests on the foundation. The load from wall segments is seen as a line load and is expressed in kiloNewtons per running meter (kN/m) and has very little lateral spread. The load per surface unit is calculated based on the width of the sill. Point cargo is the second category of cargo. There are point loads along a wall where, for example, larger openings in the wall cause point loads to occur instead of line loads. Point loads can also be found inside the foundation, loads that arise as a concentrated load on the slab. A point load can occur if the house has large open areas in, for example, a heart wall. The most common foundation type, concrete slab on ground carries higher loads through a larger/higher edge beam. An ordinary edge beam is typically cast 100 mm deeper and the edge beam can locally be made 400 mm high and sometimes with more reinforcement.

Higher loads inside the foundation are taken up by local reinforcement soles.

The concrete base usually rests on 300 mm cellular plastic consisting of 3 layers of 100 mm each. One of the cellular plastic layers can be removed locally and extra reinforcing mesh is laid approx. 50 mm from the bottom. When casting the concrete, an approx. 100 mm thick plate is formed with a reinforcing mesh centered in the middle, but locally at the reinforcements the concrete can be 200 mm thick and the extra reinforcement provides strength for the tensile stress that arises from the point load.

The upper surface of the concrete slab is subjected to compressive stress.

The bending stiffness of the local sole constitutes a load distribution. The aim is not to overload the ground under the concrete slab, which may for example consist of moraine. The cellular plastic can be locally reinforced to carry the load. In that case, this is a more expensive cellular plastic and for cost reasons such is not used throughout the house.

Soles that locally have to carry high point or line loads in a concrete slab entail additional work on the construction site. Cellular plastic with a higher density or load-bearing capacity must be purchased, shipped, sawn and assembled on site. Reinforcement must be similarly procured and cut to the correct dimensions. On the construction site, the work must be carried out, work that is exposed to the forces of the weather with rain, snow, wind and cold.

A crawl space normally consists of three beams, one for each long wall and one in the center of the house under its heart wall. Most often, beams are also laid at the gables so that the foundation of the house is enclosed. Higher point or line loads are generally solved with beams that are given a higher section and more reinforcement. Local point loads at the side of the span of the beams are supported with a shorter cross beam.

A piled foundation with sheep or several extra piles for possible point loads and the concrete slab usually has a higher section to carry better between the piles, which is why the concrete slab sometimes does not need any local reinforcement.

Plintgrund is rarely relevant for permanent houses, it is a solution that is, however, common among holiday homes.

Compensation basis is a "floating" basis. Excavated earth masses are excavated to a volume that corresponds to the weight of the house including its concrete slab. The fairs under the house and the foundation will thus be exposed to the same pressure as before the house was built, and no settlement will occur. Compensation foundation is suitable for foundations on deep clay and/or silt, a type of soil that can withstand perhaps half the load compared to moraine. The foundation here consists of capillary-breaking macadam layers with drainage. Cellular plastic is laid on top and a concrete slab at the top. Here, point and line loads are solved using the same method as with a normal concrete slab on the ground, however taking into account the usually lower bearing capacity of the soil.

Arrangement of local reinforcements takes place in the form of outdoor work with the disadvantages brought by the forces of the weather. The effectiveness of outdoor work is not only impaired by the weather. In winter, darkness becomes a problem. Workplace lighting helps, but the light will never be as good as in summer or indoors. The construction site is also burdened by earth masses from the excavation that the workers have to walk in, it becomes muddy and very dirty.

The building material thus becomes dirty and cleaning is a hopeless undertaking that is not carried out. The building material is covered by various tarpaulins and plastic packaging that are soaked by rain or covered in snow. All construction sites are different and there is no system for where everything is stored. A spontaneous placement of materials and tools means that the workers have to search to find what is needed just for the moment. It gets messy and the build quality suffers.

Known technology does not show optimal reinforcement of modules for house foundations.

Purpose and most important features of the invention One purpose of the present invention is to solve the problems with known technology and achieve a load-bearing construction of prefabricated modules that contain integrated reinforcements that take up/distribute point and line loads and thus eliminate work that is normally carried out on the construction site. The invention is achieved by locally arranging stiffeners in the structure which have the ability to carry higher loads exerted by the building. It enables prefabricated modules to also be used for more complicated houses with higher point or line loads.

The invention enables modules to be shipped with integrated reinforcements upon arrival at the construction site. Assembly of the house can therefore be done easily and quickly.

The above-mentioned and additional purposes and advantages are achieved according to the invention through a device defined in the requirements 1- Brief description of the invention The invention therefore relates to integrated reinforcements in a prefabricated module intended for a load-bearing foundation for buildings. The invention is achieved by strengthening the module locally to be able to carry higher loads.

Buildings with a foundation of modules that are designed with larger openings in interior or exterior walls need to be provided with local reinforcements. This can be achieved by using cellular plastic with a higher load-bearing capacity in the module over its entire surface, but this entails cost increases. The upper rigid layer which acts as load spreader/distributor can also be made twice as thick or more over the entire surface of the module, but this also means cost increases. To keep costs down, you cannot reinforce the entire module, you need to find solutions for local reinforcements. The elevated loads can consist of point loads (expressed in KN) caused by, for example, an open floor plan or line loads (kN/m) which are typical for walls. Walls can have point loads in the wall life, for example in the case of larger glass sections.

The prefabricated module usually comprises at least three layers, a thicker middle layer of an insulating material such as, for example, cellular plastic of suitable quality and at least one dimensionally rigid layer on either side of this middle layer.

According to the invention, the thicker middle layer of e.g. cellular plastic can be replaced locally with a material, e.g. cellular plastic, with a higher density/bearing capacity. An additional reinforcement can also be arranged directly under the uppermost rigid layer.

The inventive modules are manufactured by gluing the layers together and pressing during the curing/drying time. Before gluing, the reinforcement or reinforcements can be placed in the places in the module that are expected to have to take greater loads. It provides cost-effective manufacturing and complete modules with integrated reinforcements that can be delivered to the construction site. Even houses with higher point and/or line loads can be accommodated with this solution. Each module is thus provided with local integrated reinforcements, the module can then be easily and quickly transported, handled and assembled regardless of the weather and ambient temperature. In practice, the invention means that the work with local reinforcements is "moved indoors" with all the production advantages this brings. Further features and advantages of the invention can be seen from the following, more detailed, description of the invention as well as from the attached drawings and other patent claims.

Brief list of drawings The invention is described in more detail in the following in the form of a few preferred embodiments with reference to the attached drawings.

Figure 1 shows a plan view from above of an inventive module for a house foundation which is arranged with integrated reinforcements for the purpose of carrying higher point loads from the building.

Figure 2 shows a section through a module with a local reinforcement consisting of cellular plastic or similar cellular material that has a higher load-bearing capacity than the surrounding insulating layer, which can also be a cellular plastic.

Figure 3 shows a section through a module with a local reinforcement consisting of an additional rigid load spreading layer arranged on top of the insulating layer.

Figure 4 shows a section through a module with a local reinforcement consisting of a form-rigid load spreading layer comprising stiffening ribs.

Figure 5 shows a section through a module with a local reinforcement consisting of stiffening ribs arranged in two directions on top of the module's insulation layer.

Figure 6 shows a section through a module with a reinforcement consisting of stiffening ribs which form a distance between the upper rigid layer and the insulating layer.

Figure 7 shows a section through a module with a further variant of a local reinforcement.

Figure 8 shows a section through a module with a local reinforcement consisting of rods extending vertically through the module.

Figure 9 shows a house foundation designed as a crawl space with only three modules that function as beams and here are oriented in the longitudinal direction of the building.

Figure 10 shows a vertical section through a wall and its connection to the house foundation and where the module is reinforced under the sill.

Figure 11 shows the corresponding section through a wall where the module in the area under the sill is replaced by a material with a higher load-bearing capacity.

Description of preferred embodiments Figure 1 shows a plan view from above of a foundation 1 for a building (not shown) which in this case consists of five modules 2 assembled to form a complete building foundation 1 for a house of normal size.

The modules 2 are prefabricated in a factory and are lifted into place by, for example, a truck with a crane directly onto a prepared, leveled and packed macadam bed. The macadam bed can advantageously be constructed in the traditional way by means of excavation, geotextile, drainage pipes, coarser macadam that is topped with flnmacadam that is leveled and vibrated. The modules 2 can also be placed on the ground in another way, for example placed on beams, which in turn can be placed on a drained bed. The modules 2 are preferably placed directly on the macadam bed and fitted and fastened in a suitable manner against each other one by one.

The invention makes it possible to be able to offer the prefabricated modules even to houses that have higher point loads. It is made possible by arranging one or more locally integrated reinforcements 3 during the manufacture of the module 2, e.g. an insulating element 7 with a higher load-bearing capacity than the otherwise dominant insulating layer 5. The insulating element 7 is, for example, a cellular plastic with a higher load-bearing capacity that can bear the pressure from building elements arranged on the module 2 (not shown). The location and bearing capacity of the reinforcements 3 can normally be seen from the house's load plan, which is a drawing that shows how the building's load is distributed against the foundation. In the trade, there are cellular plastics with different load capacities, for example there is EPS (Expanded Poly Styrene) which is expanded with steam and pentane so that the cell space volume consists of approx. 98% air and 2% polystyrene. The load capacity class is usually specified in terms of the short-term load that can be carried without the material is pressed together. An example is EPS10O, which is designed for 100 kPa in short-term load. EPS100 is often used inside rooms, but under the pressure of the walls, a higher load-bearing capacity is often needed. A long-term load of a maximum of 2% over 50 years means that the compression during 50 years is not compressed by more than 2% of the original thickness of the cellular plastic. EPS is available from EPS80 up to EPS300 which carries 90 kPa in long-term load. Previously, the applied standard was 3% under 50 years, but based on experience, they have now switched to a maximum of 2%/50 years. XPS (Extruded Poly Styrene) is another way of making cellular plastic. The plastic is instead extruded and expanded with a propellant gas.

Vinyl-based cellular plastic, known under the trade name Divinycell, is often used in sandwiches for boats and wing profiles, but rarely for buildings due to cost considerations. Recycled PET plastic is used for cellular plastic manufacturing. A trade name is Dellencat. Cellulose made of PET has good mechanical properties but is still quite uncommon and expensive. Other cellular plastic materials are polyurethane foam (PUR/PIR) which is curing instead of thermoplastic. A well-known trade name is Bonocell, another Kingspan. The density is similar to EPS/XPS and its load capacity and density are also similar. The difference is the insulating ability, which for EPS/XPS with the Lambda value approx. 0.036 WmxK and PIR/PUR gives 0.022-0.024. Best Lamda value has cross-linked PIR showing as low as 0.018 WmxK. The cost of PUR/PlR is significantly higher and is therefore not used in house foundations but is more often used in walls and ceilings due to its better fire properties. Walls are much more sensitive to fire as the flames "lick" the surfaces vertically. House foundations are generally considered insensitive to fire.

Another curing foam is phenolic cell plastic. It is characterized by very good insulation and best fire safety. Unfortunately, the material is mechanically very brittle and fragile and is rarely used other than in walls and protected behind protective fire panels.

Due to its cell structure, XPS has better load-bearing capacity. Classes from XPS200 up to XPS700 are stocked in the trade. The latter carries 250 kPa in long-term load. As an order item, up to XPS2000 can be obtained and this carries approx. 600 kPa. An alternative when higher load-bearing capacity is desired is cellular glass, a glass foam with a load-bearing capacity from 450 kPa up to 900 kPa. Cellular glass has approximately the same insulation value as cellular plastic but is more expensive. For even higher load-bearing capacity, aerated concrete/lightweight concrete can be used, for example low-energy Ytong which carries 2000 kPa, Lambda 0.072 and density 300 kg/ma.

Leca blocks or light clinker consist of expanded ceramic balls bound together by cement to form blocks. Typical density is 650 kg/mß, Lambda 0.2 WmxK and long-term load 3000 kPa. This material can also be used as reinforcement. The compressive strength is very good, however, the weight and the Lambda value are not favorable.

All mentioned materials can be glued with PU glue, e.g. from Lagotech. The adhesive is slightly leavening to penetrate porosity and smooth out imperfect flatness. The open time is typically 12-15 minutes followed by 35 minutes curing time which gives 50% hold strength which is more than enough to handle the module, lift with a vacuum bell etcetera. Both degree of fermentation and curing time can be varied.

The production technology for an inventive module 2 allows that with marginal extra work reinforcements 3 with higher load capacity can be inserted where the load against the module 2 is predicted to be high.

Figure 2 shows a section through an integrated module 2 consisting of three layers or layers 4-6. An upper dimensionally rigid layer 4, an intermediate layer 5 of an insulating material, such as cell plastic, and a lower dimensionally rigid and radon-proof layer 6 directed towards the ground, for example a metal sheet.

A locally integrated reinforcement 3 in the module 2 consists, for example, of cellular plastic with a higher load-bearing capacity than the otherwise dominant insulation. The cellular plastic is chosen so that it can withstand the point load for a very long time. Module 2's at least three layers 4-6 are firmly connected to each other and form a strong sandwich construction. During manufacturing, parts of the central layer are primarily replaced with a reinforcement 3 to be able to carry higher point or line loads from the walls and roof of the building. The reinforcement 3 is designed/placed in the manufacturing process before all the different layers of the module 2 are bonded together.

The PU glue is spread manually or automatically, first on the upper side of the module 2's bottom layer 6, which can preferably consist of a metal plate/steel plate, whereupon the insulating layer 5, preferably a cellular plastic, is laid on top with the reinforcements 3 included. A further layer of glue is spread on top of all the cellular plastic and on top of this at least one further rigid layer 4 is laid. A typical method of pressing these layers together during the glue's drying/hardening time is to apply mechanical pressure. The module 2 is pressed down with, for example, weights that cover all or most of the surface of the module 2, alternatively a larger hydraulic press (not shown) is used. A simpler method is to apply a rubber sheet over the entire module 2, after which the space underneath is vacuum pumped.

When the PU glue has dried/hardened, the finished module 2 can be processed further, for example cut to size. Necessary holes/throughs can be taken up and module 2 can be packaged and labeled so that it can later be placed correctly during assembly.

Applying local integrated reinforcements 3 in module 2 thus takes marginal time and is thus cost-effective. As a comparison, the significantly larger and more time-consuming work of arranging edge beams with their reinforcement in a concrete foundation can be mentioned.

Figure 3 shows a section through an inventive module 2 which consists of three layers 4-6. The upper dimensionally rigid layer 4, for example plywood, a central heat-insulating layer 5, for example of cellular plastic, and a lower dimensionally rigid layer 6 directed towards the ground, of for example sheet metal provided with a corrosion-protective layer. A locally integrated reinforcement 3 in the module 2 here consists of a load-spreading element 8 which is arranged on top of an insulating element 7, preferably a cellular plastic with a higher load-bearing capacity than the surrounding cellular plastic in the module 2. The load-spreading element 8 is dimensioned to distribute the point load from the building.

. During manufacture, the central layer 5 in the module 2 is therefore replaced locally with the load-spreading element 8, and the insulating element 7 with high load-bearing capacity is placed below this. There are load cases where the load spreading element 8 provides sufficient load distribution so that the central layer 5 under the element 8 can be retained.

The reinforcements 3 are thus included in the manufacturing process by bonding the contact surfaces of all the layers together at one and the same time, which provides an efficient manufacturing process. Including reinforcements 3 only takes marginal extra work.

And the extra work takes place indoors instead of outdoors, which gives significant advantages.

Outdoor work is affected by weather and darkness during the winter months, by wet earth masses, dirty building materials that may be covered by wet or snow-covered tarpaulins or plastic packaging. Build quality and efficiency suffer and the risk of moisture damage arises.

Figure 4 shows a section through an inventive module 2 in accordance with Figure 3, however, where the upper load-spreading element 9 is arranged with underlying stiffening ribs 10 in order to increase the load-spreading ability. The load spreading element 9 is dimensioned so that the point load is distributed. For example, cellular plastic is arranged under the load-spreading element 9, which in turn is dimensioned to bear the increased pressure.

Figure 5 shows a section through an inventive module 2 similar to Figure 3 or 4 but where the upper load spreading element 9 is arranged with underlying and integrated stiffening ribs 9a,b arranged in two directions, for example transverse to each other, to increase the load spreading of the reinforcement 3 ability. The load-spreading element 9 with stiffening ribs 9a,b is arranged on top of an insulating element 7, a cellular plastic with a higher load-bearing capacity than the surrounding cellular plastic. The properties of the cellular plastic are chosen so that it can carry the increased point load from the building.

Figure 6 shows a section through an integrated module 2 similar to Figures 3-5 but where a load spreading element 10 consists of ribs 9c creates distance between an upper and a lower plate 10a,b which together with an insulating element 7 placed under the load spreading the element 10 forms a reinforcement 3 with the aim of increasing the load-spreading ability locally in the module 2. The insulating element 7 has a higher load-bearing capacity than the other cellular plastic in the module Figure 7 shows a section through a module 2 similar to Figures 3-6 and where the reinforcement 3 comprises a load spreading element 11 consisting of an upper and a lower plate 11a,b which are connected to each other by means of rods 9d. The bars 9d can, for example, consist of metal, plastic or lightweight concrete. The upper and lower plates 11a,b can consist of wood, metal, fiber plastic or fiber concrete. The load-spreading element 11 is arranged on top of an insulating element 7, a cellular plastic, which preferably has a higher load-bearing capacity than the surrounding cellular plastic in the module. Figure 8 shows a section through an inventive module 2, similar to Figures 3-7, where a load-spreading element 12, comprising a upper and a lower plate 12a,b, which are connected by rods 9e which extend through essentially the entire central layer 5 of the module 2 in order to increase the load spreading ability of the reinforcement 3. Between the rods 15, cellular plastic can be cast or arranged in a suitable manner and also does not need to have a higher load-bearing capacity than surrounding cellular plastic in module 2. The cellular plastic increases the thermal insulation between ground and building.

Figure 9 shows a house foundation designed as a crawl space with three oblong and narrow modules 2 that function as beams and are oriented in the longitudinal direction of the house. A module 2 is thus placed under each long wall and a third is placed in the middle of the building, under its future heart wall 17. A reinforcement 3 can, for example, be placed in the module 2 under a planned wall section.

The dashed line 18 shows in view from above the imaginary outer contours of the house. Usually, beams or similar elements are also placed along the gables of the house to enclose the crawl space.

These are not shown in the figure as they have no significance for the invention.

Figure 10 shows a section through a wall and its connection to the house foundation. The wall has a higher line load kN/m than the module 2's ordinary cellular plastic can bear for a long time and in the area under the sill 19 a reinforcement 3 is therefore arranged, in the form of only an insulating element 7, a cellular plastic, with a higher load-bearing capacity. The sill 19 is screwed to the module 2 with a sill insulation 21 in between as a seal/insulation. Facade boards/lid boards 22 are arranged with a ventilation channel 23. A drainage sheet 24 protects the sill 19 from rain or drips from the facade.

Figure 11 shows a corresponding section through a wall and its connection to the house foundation. Here too, the wall has a point load in the wall life that is higher than the module's ordinary cellular plastic can bear. In the module 2, under the sill 19, a reinforcement 3 arranged in the longitudinal direction of the wall is placed, for example in the form of a beam, which can consist of wood, metal, fiber plastic or fiber concrete. An insulating element 7 is placed under the beam, for example a cellular plastic with a higher load-bearing capacity that can handle the line load of the wall.

The description above is primarily intended to facilitate the understanding of the invention and the scope of protection is not limited to the embodiments specified here, but also other variants and embodiments of the invention are fully possible and conceivable within the framework of the inventive idea and the scope of protection of the subsequent patent claims.

Claims (9)

1. Module (2) for a load-bearing foundation for a building, wherein the module (2) comprises at least three layers (4-6) where a central layer (5) consists of a heat-insulating material and at least one upper and one lower layer (4 , 6) consists of substantially rigid materials, characterized by the fact that load-bearing reinforcements (3) are integrated into the module (2). 2. Module (2) according to patent claim 1, characterized in that the reinforcement (3) consists of a heat insulating element (7), for example a cellular plastic with a higher density/bearing capacity than other thermal insulation in the central layer (5) of the module (2). 3. Module (2) according to patent claim 1 or 2, characterized in that the heat-insulating element (7) is attached to, for example glued to, the upper and lower rigid layers (4, 6) of the module (2). 4. Module (2) according to one of the preceding patent claims, characterized in that the reinforcement (3) comprises a load spreading element (8-12) 5. Module (2) according to one of the preceding patent claims, characterized in that the reinforcement (3) comprises a load spreading element (8-12) which is made of one of the materials plywood, sheet metal, fiber plastic, fiber concrete, lightweight concrete or Leca blocks. 6. Module (2) according to one of the preceding patent claims, characterized in that the reinforcement (3) comprises rods or ribs (9a-e). 7. Module (2) according to one of the preceding patent claims, characterized in that the reinforcement (3) is arranged between the upper and lower layers (4, 6) of the module. 8. Module (2) according to one of the preceding patent claims, characterized in that the reinforcement (3) comprises a load spreading element (10-12) which is arranged with an upper and a lower plate (10a,b,11a,b,12a,b ) of a dimensionally rigid material and a spacer material placed in between (9c-e). 12 9. Module (2) according to one of the preceding patent claims, characterized in that the reinforcement (3) comprises an Iast expanding element (10) which is an extruded profile.