NO345668B1

NO345668B1 - Building element for a foundation

Info

Publication number: NO345668B1
Application number: NO20180910A
Authority: NO
Inventors: Frank Wilhelmsen
Original assignee: Sunde Broedr As
Priority date: 2018-06-28
Filing date: 2018-06-28
Publication date: 2021-06-07
Also published as: DK201970417A1; DK181065B1; SE1950820A1; NO20180910A1; SE543525C2

Description

TECHNICAL FIELD OF INVENTION

The invention relates to a building element system for foundations in houses and other buildings with equal load where the building elements have an integrated sole element eliminating the need of extra foundation at intended load situations.

More specifically, the invention relates to a building element for a foundation, comprising a longitudinal outer wall, a longitudinal inner wall arranged in parallel and spaced relation with the outer wall, and a base part interconnecting the outer wall and the inner wall, the inner wall being provided with recesses for reinforcement bars enabling reinforcement connection between the building element and the reinforcement of a concrete base slab.

BACKGROUND FOR THE INVENTION

Use of building elements for establishing foundations of for instance private houses, garages, or other buildings of similar loads are known in the building industries. The building elements of inner and outer walls and connecting steps/ribs are installed like “building blocks” where the intermediate space between two adjacent of the wall elements are reinforced and filled with concrete. The building blocks are typically made of expanding polystyrene (EPS), the steps connecting the side walls of the building blocks are typically made of plastic and the outer side of the building blocks are normally completed with a layer of fibre reinforced stucco. These building elements come in different sizes both in height and length and of different width of the steps. In cases of poor soil, before building the foundation, there is a need of establishing an extra foundation sole, which for instance is another building element system of sole elements installed like “building blocks”, requiring larger foundation width. Such sole elements are installed prior to installing the building elements of the foundation.

Products with a large foundation width exist. Such products having connection between the concrete in the floor and the concrete in the foundation system also exist. However, these are chosen on the expense of important characteristics as insulating property, giving a relatively larger thermal bridge than a solution of using a standard foundation block with both outside and insulation. Today one has to choose between a system where the concrete in the floor and the concrete in the foundation are connected, with unacceptable thermal bridge, and a system where the concrete in floor and foundation is not connected, with acceptable thermal bridge. In some places it is ok with a big thermal bridge. In some places it is ok with a big thermal bridge, but especially at colder climates and in countries with regulations that sets levels for thermal bridge the first alternative has to be chosen, and then miss the other advantages that a connected concrete system gives.

Installation of an extra foundation sole before installing building elements for foundations at sites of poor sole condition is both a required, time consuming and thereby an expensive operation and systems that connect the concrete in the floor with the concrete in the foundation are used on the expense of important characteristics. There is therefore a need of a foundation system that creates a solid and stable foundation for the building in a matter which does not decrease important insulating characteristics, and at the same time have building elements that allows larger loads to be put on the foundation without extra sole foundation being put under it for load distribution.

SE 507845 relates to a foundation element for a building comprising an inner wall element and an outer wall element, the two wall elements being spaced apart and rigidly interconnected at the bottom region by a base. The two wall elements have the same height and the inner wall element us provided with vertical slots enabling placing of reinforcement.

NO 336663 relates to a foundation element consisting of an outer wall and an inner wall, the two walls being spaced apart and where the inner wall is much lower than the outer wall. The foundation element is also provided with a base interconnecting the lower end of the foundation element, the base being in the form of ribs spaced apart, forming openings through the base element. At the top the ribs are formed with grooves for placing of reinforcement in the longitudinal direction of the foundation element.

SUMMARY OF THE INVENTION

In the following and throughout the specification bellow, the following terms means:

The term “foundation” refers to the load bearing construction constituting the interface between a house and the soil on which the house is built. The foundations primarily provide support for the vertical loads of gravity from the weight of the building above and also provide resistance to horizontal loads due to for instance ground motions, transferring loads from the structure to the ground.

The term “sole foundation” refers to a wider load bearing construction put under the foundation for extra load distribution.

The term “shift” refers to one horizontal layer of building blocks installed. Both a foundation and a sole foundation are laid in one shift each.

The term “building element” refers to the single elements or building blocks of the foundation, in which one shift of building elements stacked lengthwise constitutes the foundation.

The term “sole element” refers to prior art elements of a sole foundation, when there is need of an extra sole foundation before installing the foundation is required.

The term “reinforcement bars” refers to conventional elongated horizontal and possibly also stirrups and/or vertical reinforcement elements or re-bars of circular or oval sections. The re-bars may either be made of steel or of a fibre reinforced material.

A main object of the present invention is to provide a solid and stable connection between the concrete of the foundation and the concrete of the floor casted and surrounded by the foundation system and at the same time provide an acceptable thermal bridge (that makes the system suited for buildings with insulating needs).

Another object of the present invention is to significantly reduce the need of an extra step of installing sole foundation at sites of poor sole conditions.

Another object of the present invention is to provide a simplified installation of foundations.

It is also another object of the present invention to provide a system that may be adapted to existing building block systems of for instance walls placed on top of the foundation.

Yet another object of the present invention is to provide a broader bearing surface of the building elements for the foundations in contact with the sole/ground.

Another object of the present invention is to make a connection between the concrete of the foundation and the concrete of the floor casted and surrounded by the foundation.

Another object of the present invention is to make an insulating system where the thermal bridge as small as possible between the casted floor surrounded by the foundation and the foundation, i.e. where the heat transfer and/or the thermal capacity is eliminated, or at least substantially reduces.

Moreover, it is an object of the present invention to be able to cast the foundation and the floor surrounded by the foundation in one operation.

The objects are achieved according to the invention by an insulating building element system for a foundation and a method installing such foundation as defined in the preamble of the independent claims, having the features of the characterizing portion of the independent claims.

A number of embodiments, variants or alternatives of the invention is defined by the dependent claims.

In a first aspect, the present invention relates to a building element for a foundation, wherein of the building element is comprising a longitudinal outer wall, a longitudinal inner wall, and a number of transverse ribs/steps, connecting the outer and inner wall and embodied with tracks/grooves for reinforcement elements(bars), enable to be arranged together with another building element. The building element comprises an integrated sole element eliminating the need of extra foundation at intended load situations and/or an open space for reinforcement elements enabling reinforcement connection between the building element and the reinforcement of a concrete base slab.

Preferably, the inner wall is parallel to the outer wall.

The building element comprises the open space that enables a continuous and monolithic connection of a concrete base slab between a concrete slab and the foundation. The open space is at least one recess at the top of the inner wall of the building element.

Preferably the inner wall is lower than, 70-80%, preferably 78%, the height of the outer wall.

The inner wall comprises a horizontal longitudinal part that protrudes perpendicular in flush with the top of the inner wall, inwards the building element, protruding a distance leaving an opening between the horizontal longitudinal part and the outer wall that is 50-70 %, preferably 60 %, of the distance between the inner surfaces of the inner wall and the inner surface of the outer wall.

Preferably, an inner string is protruding upwards from the horizontal longitudinal part to the same height or to a lower height as the opposite outer wall. The inner string being a parallel offset to both the inner wall and outer wall, and/or having at least the same thickness as the inner wall and the outer wall.

The outer wall and the inner wall are connected with at least two lower transverse ribs/steps forming a base part and the outer wall and the inner string being connected with at least two upper transverse ribs/steps forming an upper part.

The building element comprises at least one hollow room between the at least two lower rib/steps and at least one hollow room between the at least two upper rib/steps. A broader hollow room for concrete between the inner wall and the outer wall than between the inner string and the outer wall makes a larger bearing surface to the ground.

Each of the transverse upper and lower ribs/steps, respectively, preferably comprises at least one cradle shaped area for reinforcement bars to rest.

The building element has recesses at the top of the inner string.

The building element is preferably made of a material of expanding polystyrene (EPS).

The longitudinal outer wall at its outer side is further mounted a finishing surface of concrete fibre sheet.

The concrete fibre sheet is mounted by use of an adhesive or held in place mechanically.

The building elements are connected together with tongues and grooves at each opposite end of the building elements respectively, wherein lower tongues are connected with lower grooves and the upper tongue is connected with the upper groove of the next building element respectively.

In a second aspect, the present invention relates to a method comprising the following steps:

● establishing levelled gate of gravel with a width of at least 700-800 mm;

● marking corners, levelling the building site and preparation for piping and other installation work;

● installation of radon barrier classification of the radon barrier, prior to or after installation of building elements of the foundation;

● installing building elements starting with corner elements of the building elements, thereafter the straight building elements are being installed, cutting and adjusting the lengths;

● locking devices, in addition to locking mechanism made from geometry on elements, are if needed placed in the joints between the installed building elements keeping the building elements together;

● inserting or threading reinforcement bars in from the side both at the upper ribs/steps and lower ribs/steps with an and tied together in longitudinal direction with wires or plastic strips;

● inserting bent reinforcement bars vertically down the building element, the horizontal part of the bent reinforcement bar resting in the recesses of the inner string pointing inwards the foundation;

● placing insulation inside the foundation/area being surrounded by the foundation at wanted height or at recommended height fitting the height of the building elements, reinforcements are laid on top for later casting of a concrete slab surrounded by the foundation;

● stabilizing masses to be filled on the outside of the foundation, optional joint or gluing with joint-filler for tightening of thermal bridges;

● filling of concrete from top of the building elements into the hollow spaces in the building elements simultaneously filling concrete in area surrounded with the foundation forming the concrete slab;

● wiping off concrete leaking from openings in the wall.

The method further involves installing a vapour barrier and/or water-born warmth installed on top of the insulation prior to reinforcement being laid on top for later casting the concrete slab.

The method also involves optionally mounting of a jointing list or glue jointing between the concrete fibre plates after wiping off concrete leaking from openings.

The new building element system is for foundations for private houses, garages, or other buildings of similar type and similar load. The new building element system comprises an integrated sole element that significantly reduces the need of installation of an extra shift of sole element prior to installing the foundation and also connects the concrete in the floor with the concrete in the foundation without making the thermal bridge unacceptable. The side walls and the steps connecting the sidewalls of the building elements are to be moulded in one preferably homogeneous or monolithic material, typically a material of expanding polystyrene (EPS), but not limited to this material, it may also be of a concrete material or similar. The surface finish of the outer wall of each building element is completed at production site, with a concrete fibre sheet glued with an adhesive or similar.

At the lower end region of the building block elements the hollow space is significantly wider than the hollow space at the upper side region. This gives a wider concrete element when the foundation is being casted by pouring concrete from above of the wall. This gives a wider/larger supporting surface to the ground. Hence, the element can carry larger load and the casting of an extra pressure distributing foundation is rarely necessary for this area of use. Recesses at the top of the inner string at the upper part of the building element make a connection between the concrete being filled into the building elements and the concrete being filled in the area surrounding the foundation, making a floor of concrete /concrete slab. This connection counteracts an eccentrically placed weigh at the outer edge of the wall that can cause a rotation of the wall. This leads to substantially improved stability of the wall and the possibility to build longer legs without reducing the stability of the wall system as well as reducing the thermal bridge that otherwise would be present.

As an alternative or an additional to the integrated sole element, the new building element may also comprise spaces in the element. The spaces, being in form of recesses, making concrete being filled in the building element, and concrete being filled in order to form a concrete slab in the area being surrounded by the building elements of the foundation as one continuous and monolithic concrete unit. The continuous and monolithic concrete unit creating an acceptable thermal bridge on one side, and where the connection on the other side is a great advantage both in terms of construction and strength in order to counteract rotation when the foundation is eccentrically loaded, as it usually is.

The building block element system functions as a shuttering during the installation phase, and there is really no need of additional support. However, scratching of some gravel at the outside of the wall may be recommended to keep the wall in place during casting of the inner wall and floor which are surrounded by the wall. The building block also functions as insulation and different type of raw material may be chosen due to better insulating property.

The elements have a tongue and groove for eased installation and are reinforced with reinforcement bars, two at the lower region of the element, threaded/inserted from the side, and two at the upper region of the element. Other types of reinforcement can also be used, like fibres. Building elements may be cut and adjusted in length for fitting and are being kept together with adjacent element through locking devices placed in the joints between the elements.

After filling the hollow space of the foundation with concrete, a joint list between the building block elements may optionally be mounted between the concrete fibre plates after wiping off concrete leaking from openings.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will now be described, by way of example only, with reference to the following diagrams, wherein:

Figure 1 shows schematically a building block system for foundation of prior art;

Figure 2 shows schematically a vertical cross-section view of an embodiment of a typically wall on top of a foundation;

Figure 3a-3d shows schematically and in perspective different views of an embodiment of a building element according to the invention;

Figures 4a and 4b show schematically and in perspective the views of an embodiment of a building element according to the invention;

Figures 5a and 5b show a detail A and detail B from figures 4a and 4b respectively;

Figure 6 shows schematically and in perspective the view of one embodiment of an installed building element with reinforcement bars and bent reinforcement bars 31 and insulation plates in the inner side of the foundation;

Figure 7 shows schematically and in perspective the same as shown in Figure 4, but with two building elements installed along each other;

Figure 8 shows schematically a top view of one installed building element with reinforcement bars arranged, ready for pouring of concrete;

Figure 9 shows schematically a top view of one building element with marked cross sections A and B; and.

Figures 10a-10b shows schematically a vertical section of the building element shown in Figure 9, see along the lines A and B of Figure 9 respectively.

DETAILED DESCRIPTION OF EMBODIMENTS

The following description of the exemplary embodiments refers to the accompanying drawings. The drawings illustrate exemplary embodiments of the invention configured to be integrated in building block systems. The exemplary embodiments disclosed in the drawings should not be understood as a limitation to the scope of protection of the invention, merely to illustrate certain aspects of the invention.

The same reference numbers in the different drawings identify the same or similar elements. The following detailed description does not limit the invention. Instead, the scope of the invention is defined by the appended claims.

Reference throughout the specification to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with an embodiment is included in at least one embodiment of the subject matter disclosed. Thus, the appearance of the phrases “in one embodiment” or “in an embodiment” in various places throughout the specification is not necessarily referring to the same embodiment. Further particular features, structures or characteristics may be combined in any suitable manner or in one or more embodiments.

When referring to vertical and horizontal, reference is made to a building element resting on a horizontal surface.

Figure 1 shows schematically a view in perspective of a section of a prior art foundation system with a building element 10 placed on a sole element 40, where reinforcement bars 30 are placed in both the building element 10 and in the sole element 40 and thereafter filled with concrete. The sole element 40 is considerably wider than the building element 10 of the foundation; in order to give a more stable and sufficient sole foundation for the wall.

Figure 2 shows schematically a view of an end section of a typical assembly of a wall 35 typically installed about seven days after installation of the foundation when the concrete has been cured sufficiently. A XPS insulation plate 33 is placed at the outside of the foundation for frost protection, since the ground is not usually frostfree. This insulation 33 has the same horizontal length as the depth of the average ground frost for that specific area of installation to prevent damages to the foundation. The XPS insulation 33 plates at the outside of the foundation shall have a 10-20 cm of masses on top, typically masses of earth and gravel. Insulation 32 is placed at the ground encircled by the foundation to sufficient height before the concrete slab is being casted together with the concrete inside the building elements 10. The Figure 2 shows a monolithic connection between the concrete 34 of the concrete slab making the floor inside the foundation and the concrete 34 inside the building element 10 of the foundation, with bent reinforcement bar 31 being reinforcing throughout the monolithic connection. Horizontal placed reinforcement bars 30 being placed lengthwise inside the building element 10 are reinforcing the concrete throughout the inside of the building elements 10 forming the foundation.

Figures 3a-3d show schematically and in perspective different views of an embodiment of a building element 10 according to the present invention. The building element 10 comprises in longitudinal direction an outer wall 12, Figure 3a, and an inner wall 11, Figure 3c, the inner and outer walls being parallel. The inner wall 11 is lower in height than the outer wall 12 and comprises a horizontal longitudinal part 20 protruding perpendicularly out from the top of the inner wall 11 in inwards the building element 10 and being formed with an upper horizontal surface. An inner string 17 extends upwards from the horizontal surface of the longitudinal part 20 to the same height as the height of the opposite outer wall 12, the outer side of the inner string 17 being sideways offset to the outer side of the inner wall 11 of about 30 % of the distance between the outer sides of the inner wall 11 and outer wall 12, respectively.

The inner wall 11, upward restricted by the horizontal longitudinal part 20, and the outer wall 12 constitute a base part 16, Figure 3b, provided with at least three transverse, intermediate lower ribs/steps 14 extending between the inner surface of the inner wall 11 and inner surface of the outer wall 12. The inner string 17 and outer wall 12 are downwardly restricted by the horizontal longitudinal part 20 constitute an upper part 15, Figure 3b, with at least two transverse intermediate upper ribs/steps 13 extending between the inner string 17 and outer wall 12.

The inner string 17 comprises at least one downwardly extending recess 21 positioned between the at least two transverse intermediate upper ribs. The building elements 10 comprises hollow spaces restricted by the outer wall 12, inner wall 11, inner string 17, transverse upper and lower ribs 13, 14 with lower hollow rooms at base part 16 and upper hollow rooms at upper part 15. The hollow spaces define the space for filling concrete. The distance between the inner surface of the inner wall 11 and inner surface of the outer wall 12, forming the hollow space in the base part 16, is about one and a half time the distance between the inner string 17 and the outer wall 12 making the hollow space of the base part 16 about one and a half time broader than the hollow space of the upper part 15, giving a sufficient width for sole foundation purposes of the integrated sole element of the building element 10. This broader base of concrete gives a larger bearing surface to the ground, eliminating the need of a sole element 40 as described in Figure 1.

The Figures 3a-3d show four transverse upper ribs/steps 13, but is not restricted to four, it may be fewer, and it may be more with regards to the length of the building element 10. The Figure 3a-3d shows six transverse lower ribs/steps 14, but is not restricted to six, it may be fewer, and it may be more with regards to the length of the building element 10.

The building elements 10 are connected together with tongues and grooves at each end of the building elements 10. At least one tongue 24 at upper part 15 are connected with a complementary groove 25 (not shown) at the opposite end of a next building element 10. Optionally elements of lower tongues 22 at base part 16 may be connected with optionally elements of complementary lower grooves 23 at the base part 16 at the opposite end of a next building element 10. The design and geometry of the tongues and grooves is not limited to what is shown in the sketches but can have other shapes.

The hollow space between the ribs/steps 13, 14 has vertical recesses 27, 28 in the outer wall 12. The recesses 27, 28 in both the upper part 15 and base part 16 make the concrete core in the building element 10 broader giving a less eccentric placed/loaded ground beam on top of the building element 10, which in turn improves the stability and ability to guide/lead load down into the ground.

Figures 4a and 4b show schematically and in perspective different views of an embodiment of a building element 10 according to the present invention.

Figures 5a and 5b show a detail A and detail B from figures 4a and 4b respectively. Detail A shows a tongue 24 and detail B shows a groove 25. One building element 10 are connected with one end with its tongue 24 to a groove 25 of an opposite end of another building element 10 in order to build a foundation.

Figure 6 shows schematically and in perspective the view of a single installed building element 10, where reinforcement bars 30 are inserted/threaded into the building element, and with pre-bent reinforcement bars 31 threaded vertically down in the building element 10 and bent 90 degrees, resting over the upper set of reinforcement bars 30 and positioned in the recesses 21 of the inner strings 17, the horizontal part being positioned a required distance above the upper surface of the insulation 32 to secure the required concrete coverage. The bent reinforcement bars 31 are pointing inwards over the built foundation, enabling connection with the reinforcement of the concrete base slab 34 to be casted. One or more layers of insulation 32 are placed in the room restricted by the foundation, but not higher than the fundament surface 20 for inner string 17. The foundation and the inner room restricted of the foundation are to be filled with concrete to the height of the building element 10. The concrete may make a continuously and monolithic connection between the concrete slab and the concrete of the foundation through bridges between the concrete slab and the concrete of the foundation made in the recesses 21 in the inner string 17.

Figure 7 shows schematically and in perspective the view of two installed building elements 10 as shown in Figure 6for illustration of how building elements 10 are stacked sideways.

Figure 8 shows a top view of a building element 10 with reinforcement bars 30 and bent reinforcement bars 31.

Figure 9 shows a top view of the building element 10. A concrete fibre sheet 26 is shown making the surface finish of the outer wall 12, where each building element 10 is completed with a concrete fibre sheet 26 at production site.

Figures 10a and 10b show cross sections A and B of the building element 10 seen along the lines A-A and B-B respectively n Figure 9. Figure 10a shows the cross section through the lines A-A of the upper rib/step 13 of the building element 10. The upper rib/step 13 is provided with a cradle shaped surface 18 where reinforcement bars 30 can be placed for rest. Figure 10b shows the cross-section B through lower rib/step 14 of the building element 10. The lower rib/step 14 is provided with a cradle shaped area 19 where reinforcement bars 30 can be placed for rest. The upper rib/steps 13 have at their bottom (not shown), a tapered shape in order to prevent up-floating of the building element 10 during concrete filling as may be a problem with a flat bottom.

Table 1

Claims

1. Building element (10) for a foundation, comprising a longitudinal outer wall (12), a longitudinal inner wall (11) arranged in parallel and spaced relation with the outer wall (12), and a base part (6) interconnecting the outer wall (12) and the inner wall (11), the inner wall (11) being provided with recesses (21) for reinforcement bars (31) enabling reinforcement connection between the building element (10) and the reinforcement of a concrete base slab,

characterized in that the base part (6) comprises a number of ribs (14) spaced apart in longitudinal direction, forming recesses (28) through the base part (6) between adjacent ribs (14), and that the outer wall (12) and the inner wall (11) are interconnected at their upper end by a number of transverse ribs (13) spaced apart in longitudinal direction, forming recesses (27) between adjacent ribs (13) at the upper part (15), the upper ribs (13) at the upper end being in vertically spaced relation with the ribs (14) at the base part (16).

2. Building element (10) according to claim 1, wherein height of the inner wall (11) being lower than, 70-80%, preferably 78%, the height of the outer wall (12).

3. Building element (10) according to claim 2, wherein the inner wall (11) comprising a horizontal longitudinal part (20), protruding perpendicular in flush with the top of the inner wall (11) inwards the building element (10) protruding a distance leaving an opening between the horizontal longitudinal part (20) and the outer wall (12) being 50-70 %, preferably 60 %, of the distance between the inner surface of the inner wall (11) and the inner surface of the outer wall (12).

4. Building element (10) according to claim 3, wherein an inner string (17) is protruding upwards from the horizontal longitudinal part (20) to the same height or to a lower height as the opposite outer wall (12), being a parallel offset to both the inner wall (11) and outer wall (12), and/or having at least the same thickness as the inner wall (11).

5. Building element (10) according to claims 4, wherein the building element (10) comprises at least one hollow room between the at least two lower ribs/steps (14) and at least one hollow room between the at least two upper rib/steps (13), wherein a broader hollow room for concrete between the inner wall (11) and the outer wall (12), than between the inner string (17) and the outer wall (12) makes a larger bearing surface to the ground.

6. Building element (10) according to claim 5, wherein each of the transverse upper and lower ribs/steps (13, 14), respectively, comprises at least one cradle shaped area (18, 19) for reinforcement bar (30) to rest.

7. Building element (10) according to one of the claims 4-6, wherein the building element (10) has at least one recess (21) at the top of the inner string (17).

8. Building element (10) according to one of the claims 1-7, wherein the building element (10) is made of a material of expanding polystyrene (EPS).

9. Building element (10) according to one of the claims 1-8, wherein the longitudinal outer wall (12) at its outer side is further mounted a finishing surface of concrete fibre sheet (26).

10. Building element (10) according to claim 9, wherein the concrete fibre sheet (26) is mounted by use of at least one of the following; an adhesive and mechanically by a locking list and/or clips.

11. Building element (10) according to one of the claims 1-10, wherein the building elements (10) are connected together with at least one tongue (24) and at least one groove (25) at each opposite end of the building elements respectively, wherein the at least one tongue (24) are connected with the at least one groove (25) of the next building element.