SE532781C2 - Basis and method of laying foundation for buildings - Google Patents

Description

20 25 30 40 m. M '. : ___ t, 2 effective and fireproof insulation but which does not risk moisture and mold forming in the construction, but allows the building's walls to breathe. Overly dense houses, in order to achieve effective insulation to save energy, have instead caused trapped moisture in the construction and created a mold problem that has made the development of the construction industry not only an economic issue but also a public health issue.

Lightweight concrete building blocks with volume weights between 400 - 800 kg / m3 have been manufactured since 1930. The first lightweight concrete was based on alum shale. In the 1970s, however, the inadequacy of using this material as it contained uranium-emitting radon was criticized, which led to the cessation of alumina slate-based aerated concrete in 1975. Thereafter, aerated concrete has continued to be produced from, among other things, finely ground sandstone, cement and lime, which are brought to expand in an autoclave through gas evolution caused by the heating of aluminum powder in the recipe. These building blocks are usually manufactured in smaller units that are stacked and joined together at the workplace, to compare with the construction of a wall. However, the capillary suction power is so strong in these materials that moisture absorption risks significantly reducing the insulation capacity, depending on installation and use.

A method of mixing lightweight expanded polystyrene (EPS) foam particles into the cement mixture was launched as early as the 1950s and has found some use as lightweight concrete ballast at higher bulk weights, about 1000 kg / m3 or more, which in itself is a significant weight reduction. from the normal density of the concrete of about 2,400 kg / m3. The problem has been to obtain a homogeneous mixture as the foam balls float up in the water mixture. This problem is currently affordable and EPS particles treated for the purpose can be purchased on the market. This development has also made possible the advent of the present invention.

When a foundation is to be cast into a building, it must be insulated from the ground.

A major practical problem arises when commonly used foam insulation is used. Loose insulation boards are laid out on a base bed of e.g. gravel, in 2-3 layers. The loose insulation boards must be fitted tightly to each other and partly cut exactly to also fit tightly against the plinth elements, an accuracy that is never possible to achieve in the workplace. The same problem also applies to the insulation around electrical and "VA connections. Where cracks are left, concrete water then flows down as hardened during casting and creates permanent cold and damp bridges. out on top of the foam, with all that entails of physical exertion, thereby further easily causing further damage in the form of deformation and cracks in the foam boards before the concrete is finally poured over and seals the structure. , Itïti ... '21 Summary of the invention The object of the invention is to achieve a simplified, quality-seeking, cost-effective, resource-efficient, environmentally friendly, non-combustible, high-strength, vapor diffusion-open foundation for buildings based on cement or other mainly inorganic material but with low bulk density. the material also provides built-in insulation.

A building material intended for a foundation according to the invention contains highly insulating EPS particles or particles of other insulating material or medium mixed in a cement mixture or other mainly mineral-based building material which hardens when it reacts with water. Due to their admixture in the wet building mass, the particles give the resulting hardened solder material a volume weight after curing of about 50 - 800 kg / ma, the compressive strength is more than 0.5 MPa and has a thermal conductivity k less than 0.15. Preferably, the volume weight is 300-600 kg / m3 and preferably 400-500 kg / m3. Preferably, the compressive strength is more than 1.0 MPa and preferably more than 2.0 MPa. Preferably, the thermal conductivity number is less than 0.12 and preferably less than 0.10. The insulation particles are moisture-proof and preferably have a bulk density of less than 50 kg / m 3, more preferably less than 30 kg / m 3. Most preferably, the particles have a bulk density of up to 15 kg / m 3. The volume weight is generally inversely related to the thermal conductivity number k, ie [u lower volume weight the higher the insulation value. The desired volume weight of the final product can be determined according to the mixture of the amount of particles. Preferably, a mixture containing at least 50% by volume of expanded cells of expanded polystyrene (EPS) insulating particles with closed cells or other non-moisture absorbing material or medium having a bulk density not exceeding 30 kg / m 3 is used. Even eg blowing agent, air or other medium can be added to the mixture. The insulating particles may have, for example, graphite or aluminum admixture for increased insulating ability. The particles can have different fractions of different sizes for improved degree of filling. Without different fractions, air spaces are created between the concrete-coated and adhering particles, which thereby gives the mixture greater insulation value, ie thermal conductivity. The insulation particles can have all shapes but are preferably spherical to obtain optimal strength in the concrete shell formed around each particle. constructing scaled particles. For increased strength in the concrete shell, for example, glass particles can be added to the cement mixture.

A material mixture suitable for the invention and sweetly prepared for this invention can obtain a / a thermal conductivity number (lambda value) of less than 0.15, preferably about 0.0-0.12, b / a compressive strength of at least 0.5 MPa, preferably at least 1.0 MPa , 10 15 20 25 30 35 40 .fi LJ Fu ... J fr: ... a 4 c / a vapor passage resistance between 0 000 - 400 000 s / m, preferably between l0 000 -l 00 000 s / m, preferably between 10,000 - 30,000 s / m.

The method according to the invention to cast a foundation for buildings of the building mass according to the invention comprises the step of laying prefabricated molded plinth elements on a balanced, stable and drained surface to then cast the foundation containing the insulation function between the plinth elements. In this way, the problem of how the foundation is to be insulated is eliminated and, for example, the above-mentioned problem of insulating boards falling apart, breaking or not being sufficiently well fitted to base elements and connections. Preferably, the building mass is liquid and preferably also pumpable. When the building mass is cast, it fills the space inside the base elements mounted around it, and encloses laid reinforcement as well as pipes and pipes. The insulation is thereby carried out completely according to calculated values, without the possibility of hidden faults.

The plinth elements used around the foundation and for load-bearing interior walls are made of the same type of building material used for the foundation. In this way, the total floor area of a building is isolated. preferably the base element has a form fit and can be assembled with a form fit of one or more adjacent base elements so that they cannot be displaced mutually laterally while they mutually seal against cement water during casting. Form fit is defined as any integrated profile or recess that is used in assembly to position or lock two socket elements abutting each other. This shall also include possible solutions with separate details that are fitted in the first fitting of a first plinth element, and then when fitting a second plinth element, the separate detail (s) shall be fitted in the fitting of the second plinth element. For example, each plinth element may be provided with a longitudinal insert in which one or more blades or the like are inserted into the insert of each building element during joining, similar groove and sheet pile joining. The overall idea is to create a positioning or locking of the base elements, where the person skilled in the art can design the positioning or reading in the desired manner in different embodiments of the invention.

The plinth element is preferably provided with at least one reinforcement which is cast in and at least one fastening device which extends from the plinth element on the side which in use faces inwards the building. Preferably, the reinforcement in the base element and the fastening devices are connected. The fastening devices can be used for attaching a reinforcement to the foundation, after which the foundation is cast.

On the outside of the base element, in mounted position, a plaster layer of mineral thick plaster is preferably applied, with a capillary suction force which is greater than the L of the element 10 15 20 25 30 35 40 L, i tliÉ-.i ii-J ~ ..l fi? ... Zl 5 capillary suction power, which guarantees that the base element is always dry while maintaining insulating ability. The outer mineral plaster layer serves partly as reinforcement, leveling, paint decoration layer and moisture absorber / moisture regulator, which guarantees that the insulation value of the plinth element is maintained by always keeping the pores of the plinth element dry. The plaster layer of mineral thick plaster can be applied prefabricated in the factory or on site at the construction site. The outside of the plinth element is completely or partially provided with the plaster layer, however, the plaster layer must not be in contact with the ground in the mounted position.

The building's walls, roof joists and any intermediate joists are preferably erected before the foundation is cast, ie the casting takes place indoors in their own house only after the building has been erected, which means that the foundation is cast and hardens under controlled conditions in all seasons.

The base is preferably provided with a surface putty layer, which constitutes a pressure-equalizing surface reinforcement. In cold climates, underfloor heating is a good and even heating in a house. According to the invention, the floor heating coils are laid in the surface putty layer and are therefore insulated against energy losses downwards through the insulating building mass. With heating coils cast in a conventional concrete foundation floor, the heating of the room is considerably delayed by the solid concrete foundation first being saturated by the heat before it is released into the room. In a corresponding manner, the cooling is delayed. It is also conceivable to provide the surface putty layer with a reinforcement.

With this foundation and method of casting the foundation based on lightweight building mass according to the invention, a number of advantages are achieved in relation to the prior art: type of material with the same insulation value, which is why no cold drafts occur in the connections between the different parts. 2 / The base is non-combustible. 3 / The foundation is load-bearing. 4 / The base is vapor diffusion open (breathable). 5 / The base is insulating. ó / If the foundation is cast in an indoor environment, the environmental problems that otherwise apply at a construction site are avoided, which is why the quality is significantly higher and richer.

A further problem that the basis according to the invention solves is that the insulation particles of, for example, expanded polystyrene, which is the same material as in the usual insulation boards, are embedded in the cement mixture and therefore inaccessible to small animals that would otherwise gnaw into and build nests in foam-insulated concrete foundations. Brief Description of the Drawings The present invention will now be described in more detail with reference to the accompanying drawings, in which: Fig. 1 shows from above an embodiment of a foundation according to the invention which is ready for casting with building material according to the invention comprising six plinth elements with applied reinforcement in between, and Fig. 2 shows a plinth element according to an embodiment of the present invention in cross section with reinforcement and fastening device.

Detailed description of preferred embodiments of the invention The basis for buildings comprises plinth elements (1) between which plinth elements building mass is poured. The building stock is based on e.g. cement or other substantially inorganic material, as cured in an aqueous mixture, with admixture of expanded polystyrene (EPS) particles with closed cells or other insulating material or medium. Preferably, the cast compound cast in place has a volume weight between 300 - 600 kg / m3. The compressive strength is preferably at least 1.0 MPa and the thermal conductivity X less than 0.1 .2 Preferably, the building mass is liquid and preferably also pumpable. The insulation particles are moisture-tight and preferably have a bulk density of less than 50 kg / m 3, more preferably less than 30 kg / m 3. Most preferably, the particles have a bulk density of up to 15 kg / ms. The volume weight is generally inversely related to the thermal conductivity number k, ie [u lower volume weight the higher the insulation value. The desired volume weight of the final product can be determined according to the mixture of the amount of particles. Preferably, a mixture containing at least 50% by volume of expanded polystyrene (EPS) insulating particles with closed cells or other non-moisture absorbing material or medium having a bulk density not exceeding 30 kg / ms is used. Even eg blowing agent, air or other medium can be added to the mixture. The insulating particles may have, for example, graphite or aluminum mixture for increased insulating ability. The particles can have different fractions of different sizes for improved degree of filling. Without different fractions, air spaces are created between the concrete-coated and adhering particles, which thereby gives the mixture a lower insulation value, ie thermal conductivity. The insulation particles can have all shapes but are preferably spherical to obtain optimal strength in the concrete shell formed around each particle adjacent scaled particles. For example, two fractions can be mixed where preferably the first fraction of particles has a size up to 1.5 mm and the second fraction preferably has a size between 1.5 mm and 3 mm. The first fraction may constitute 20% and the second fraction may constitute 80% as a 10 15 20 25 30 35 40 in 'W! * m I i if f '' l "'.l lzll-RÃ goal 7 example. For increased strength in the concrete shell, for example, glass particles can be added to the cement mixture.

The method according to the invention to cast a foundation for buildings of the building mass according to the invention comprises the step of laying prefabricated molded plinth elements around or in the coming foundation on a balanced, stable and drained surface to then cast the foundation of building mass according to the invention between the plinth elements. The plinth elements used around the foundation and for load-bearing interior walls are made of the same type of building material used for the foundation. In this way, the total floor area of a building is isolated.

The underlying basis, on which the basis according to the invention is to be carried out, may consist of e.g. packed macadam or washed shingle, e.g. 15 cm and horizontally balanced. A drainage cloth can advantageously be laid over the base bed to prevent cement water from flowing down through the base bed and then solidifying and forming moisture or cold bridges.

The building's walls, roof joists and any intermediate joists are preferably erected before the foundation is cast, ie the casting takes place indoors in their own house only after the building has been erected, which means that the foundation is cast and hardens under controlled conditions in all seasons.

Preferably, the base element has a form fit and is compatible with a form fit of one or more adjacent base elements. Fig. 1 shows an embodiment of the invention in which six base elements 1 are laid out. The base elements 1 are preferably provided with form fits 2 at its end portions for assembly with adjacent base elements 1. In this way a positioning or reading of the base elements 1 is created.

The base element 1 can be as wide as the wall element or wider than a wall element, for example 50-7070 wider and then preferably has a downwardly sloping surface on a part of the upper portions which extend beyond the thickness of a wall element. The extra width stabilizes the base element 1 and minimizes the possibility of the frost to creep into the joint between the base element 1 and the wall element 3 and the sloping surfaces cause rainwater to run off the base elements 1.

On the outside of the base element 1, in mounted position, a plaster layer of mineral thick plaster is preferably applied, with a capillary suction force which is greater than the capillary suction force of the element, which guarantees that the base element is always dry while maintaining insulating ability. The outer mineral plaster layer serves partly as reinforcement, leveling, paint decoration layer and moisture absorber / moisture regulator, which guarantees that the insulation value of the plinth element is maintained by always keeping the pores of the plinth element dry. The plaster layer of mineral thick plaster can be applied prefabricated in the factory or on site at the construction site. The outside of the plinth element is completely or partially provided with the plaster layer, however, the plaster layer must not be in contact with the ground in the mounted position. Fig. 2 shows a reinforcement cage 13 cast in a plinth element i. From the reinforcement cage 13 extends a fastening device 14 which projects onto the side of the plinth element 1 on the side which, during assembly, faces inwards the building. In these fastening devices 14, reinforcement 15 can be fastened between the base elements in order to form the reinforcement in the later ground cast in place, as shown in Fig. 1.

Reinforcement can be a one-, two- or three-dimensionally shaped reinforcement construction adapted for each construction, of e.g. metal mesh, embedded in the element to be able to withstand very high load requirements both vertically and horizontally. The reinforcement structures can also be cast at an angle, trapezoidal or in another shape.

The cast reinforcement structures 15 can also serve as anchors for, e.g. in combination with cast-in metal and metal-welded-in reinforcement construction, fastening devices included in the building elements. As an example, metal wire with a diameter of 6-8 mm can be joined to a nut with, for example, square decimetre-sized gaps. The nut can be shaped or pressed into the desired shape.

When casting conventional concrete, two reinforcement layers are usually required to counteract crack formation during drying. With a primer according to an embodiment of the invention, only a reinforcing layer is needed, preferably in the middle of the laid building mass, as there is no risk of crack formation during drying.

The base is preferably provided with a surface putty layer, which constitutes a pressure-equalizing surface reinforcement. In cold climates, underfloor heating is a good and even heating in a house. According to the invention, the floor heating coils are laid in the surface putty layer and are therefore insulated against energy losses downwards through the insulating building mass. With heating coils cast in a conventional concrete foundation floor, the heating of the room is considerably delayed by the solid concrete foundation first being met by the heat before it is released into the room. Correspondingly, the cooling is delayed. It is also conceivable to provide the surface putty layer with a reinforcement.

The base according to the invention, with integrated insulation, may for example have a thickness of e.g. 400 mm in areas with winter climates, plus 13 - 20 mm surface putty layer, but can be e.g. 100 mm plus putty layer in warmer climates, 10 1 in fl twl FU "ml LI)» III 9 or thicker depending on whether a higher insulation value, eg in air conditioning, is desirable.

A primer according to the invention with a thickness of 400 mm dries out in about 3 days, to which is added 10-14 days for the surface putty layer, which means a significant time saving in comparison with ltus primer made of conventional concrete. As an example, a conventional concrete foundation with a thickness of 70 - 150 mm (cast on top of 400 mm cellular plastic insulation) needs a drying time after casting of about 3 - 6 months. At the same time, the sensitive Sat is a Sat dry drying out as microcracks can occur which weaken the foundation and can lead to settling.

Claims (7)

1. 0 15 20 25 30 35 40 10 Patent claim l. Primer for buildings, which includes plinth elements (l) between which plinth elements (l) building material is pourable, the building material is based on cement or other substantially inorganic material belonging to a water mixture and comprising the incorporation of particles of expanded polystyrene or other insulating material, sex characteristics of that the volume weight of the cast-in-place building mass is between 50 - 800 kg / m3, the compressive strength is more than 0.5 MPa and the foundation has a thermal conductivity number of less than 0.15 and that the plinth elements (l) are cast from the same type of building mass as the foundation and that the plinth elements (l) are provided with a reinforcement (l 3) which is cast in and at least one fastening device (l4) which extends from the plinth elements (l) on the side which in use faces into the building, in which a reinforcement (l 5) is fixed between the base elements (1) by means of the fastening devices (14). Primer according to Claim 1, in which the building mass contains at least 50% by volume of expanded polystyrene (EPS) insulating particles with closed cells or other non-moisture-absorbing material or medium with a bulk density not exceeding 30 kg / ms. Primer according to claim 1 or 2, in which the plinth element (1) is prefabricated of building material according to claim 1. Primer according to claim 1, 2 or 3, in which the base element (1) is provided with at least one form fit (2) and can be assembled with a form fit (2) of one or more adjacent base elements (1). Primer according to any one of the preceding claims, in which a surface putty layer with its own reinforcement is arranged on top of the upper surface of the primer. oh. A method of casting a foundation for building materials according to claim 1 or 2, wherein prefabricated molded plinth elements (1) of building material according to claim 1 are laid on an unweighted, stable and droned surface, after which the foundation is cast between the plinth elements (1), wherein a reinforcement (l5) is fastened between the plinth elements (l) before the foundation is cast. A method according to claim 6, wherein walls, roof joists and any intermediate joists are erected before the foundation is laid.