BINDING ELEMENT FOR A BUILDING WALL STRUCTURE

Abstract

A binding element for a building wall structure, wherein said binding element comprises an elongated steel element coated with a thermoplastic material, and wherein the coated thermoplastic material has a uniform thickness on each straight portion of the elongated steel element. The building wall structure comprising an inner wall, an outer wall spaced from said inner wall and provided with at least one insulation layer(s) in between, at least one binding element comprising an elongated steel element coated with a thermoplastic material interconnecting said outer wall and inner wall through the insulation layer, wherein ends of said binding element is fixed to the said outer wall and said inner wall respectively and wherein middle portion of said binding element is in contact with the said insulation layer(s). The binding element may comprise a intermediate metallic coating selected from a group consisting of copper, copper alloy, zinc, zinc alloy, nickel, nickel alloy, tin or tin alloy or combinations thereof.

Description

TECHNICAL FIELD

The present invention relates to use of a binding element for a building wall structure, particularly to binding elements having a thermoplastic coating. The binding element has been developed primarily for use in construction industry for wall structures made of concrete, brick, and wood or like composition layers, and will be described hereinafter with reference to this application.

BACKGROUND ART

A metal rod that joins and reinforces parts in a structure is well known in the art. Insulated concrete walls are held together with plurality of such metal rods and are widely used in the construction industry for buildings. Galvanized wire was often used as a metal rod for this purpose. In meantime, energy conservation has become a vital component in the construction industry and developments were focused on increasing thermal insulation and reducing cold bridges between outer and inner walls. Hence a split hook was developed which functions as a static connection between the outer and inner wall, provides a fixation of the insulation layer and does not form a cold bridge between outer and inner wall. A typical split hook has two components: a metal wire and a plastic plug. EP 0502302, DE8008619 and DE8606959 are few examples describing the split plug system. The problem often encountered is the installation of such split hook which is a cumbersome process involving multiple steps such as drilling a hole in the outer wall, hammering the plug in to the hole, installing the metal wire in to the plug, covering the metal wire with a shield, hammer the metal wire in to the plug and removing the shield. Another disadvantage of this system is strength. The location of the drilled holes is rather random, sometimes a lot of anchoring in bricks will occur and sometimes limited anchoring will occur when the split hook is going through a hole in the brick.

SUMMARY OF THE INVENTION

It is an object of at least certain embodiments of the present invention to devise a binding element for a building wall structure of concrete or like composition which address the drawbacks of the present split hooks in the market.

It is an object of at least certain embodiments of the present invention to devise a binding element that is easier to install in the wall structure.

It is an object of at least certain embodiments of the present invention to devise a binding element that is resistant to corrosion and fire.

It is an object of at least certain embodiments of the present invention to devise a binding element that has a minimal heat conduction coefficient.

In one aspect, the present invention relates to a use of a binding element for a building wall structure, wherein said binding element comprises an elongated steel element coated with a thermoplastic material, and wherein the coated thermoplastic material has a uniform thickness on each straight portion of the elongated steel element. Herewith, “uniform thickness” means the thickness of the coating is substantially same all over each straight portion of the elongated steel element. The tolerance of coating thickness is within 30%, preferably with 10%, and more preferably with 5%. The thermoplastic material coating is preferably a continuous coating, i.e. the thermoplastic material is coated all over the elongated steel element. Moreover, as explained in the following the binding element may be bent, especially at two ends. At the bent portion, the coating thickness may have big tolerance, such as 70% or 50%. The inner side of the bent portion may have thicker coating while the outer side of the bent portion may have thinner coating. The coating may be formed by any available coating method, such as extrusion. One of many advantages of the present invention is the ease in installation of such binding elements in the wall structure. The ends of the binding element can be for instance fixed for example in a bent state in the masonry joint of the brick wall. Furthermore the ratio of thickness of thermoplastic coating and the steel element may be altered to provide better thermal insulation. The thermal conductivity of such binding elements is minimal.

In one aspect, the present invention relates to a building wall structure of concrete or like composition comprising an inner wall, an outer wall spaced from said inner wall and provided with at least one insulation layer(s) in between, at least one binding element comprising an elongated steel element coated with a thermoplastic material interconnecting said outer wall and inner wall through the insulation layer, wherein ends of said binding element are fixed to the said outer wall and said inner wall respectively and wherein middle portion of said binding element is in contact with the said insulation layer(s).

BRIEF DESCRIPTION OF FIGURES IN THE DRAWINGS

FIGS. 1 and 2 shows a lateral view of a wall structure depicting the embodiment according to the invention.

FIGS. 3 to 10 shows different embodiments of the invention relating to the binding element.

MODE(S) FOR CARRYING OUT THE INVENTION

FIG. 1 depicts a building wall structure of concrete or like composition comprising an inner wall (18), an outer wall (12) spaced from said inner wall and provided with an insulation layer (16) in between, at least one binding element (20) interconnecting said outer wall and inner wall through the insulation layer, the said binding element (20) comprises a elongated steel element (24) preferably having a minimum tensile strength of at least 100 N/mm² coated with a thermoplastic material (22) of a uniform thickness.

In one embodiment of the present invention, the elongated steel element (24) is coated with thermoplastic material (22) of a substantially uniform thickness in its entire length and said binding element has two edges and the thermoplastic material is not coated thereon, as shown in FIG. 1 and FIGS. 3 to 6. This configuration can significantly simplify the production process and thus reduce the cost of the binding element. A bundle of steel wire can be first continuously coated with thermoplastic material, such as by extrusion. Then the coated steel wire can be cut into the desirable length and ready to be in use as a binding element or can be used after certain deformation.

In one embodiment of the present invention the elongated steel element (24) is coated with thermoplastic material (22) preferably the middle portion and end portion of binding element fixed to the outer wall (12), more preferably the middle portion of the binding element. The middle portion of the binding element is the represented as that length which equates the spacing between outer wall (12) and inner wall (18). In other words the thickness of insulation layer(s) (16) and the spacing (14) should represent the middle portion. The binding element may be secured to the insulation layer by using a stopper (26).

FIG. 2 depicts a brick wall structure showing layers of brick wherein the binding elements are fixed in a bent state in to the masonry joint during brick wall construction. As an example, the number of binding elements ranges from 4 to 5/m² of the wall structure. When a total tensile strength of 3500 N/m² is intended to reach, this means in the case of 4 binding elements are applied per square meter, 875 N per binding elements is required. When a steel wire with a diameter of 4 mm is used, resulting in a required tensile strength of the wire of 70 N/mm². When a steel wire with a diameter of 3 mm is used, a minimum tensile strength of 125 N/mm² is required. In order to keep the binding element made of steel wire in function, in particular for a longer time, the tensile strength of binding element is at least 100 N/mm².

The binding elements have a standard length of 15-20 cm, may have a higher range from 40-60 cm, such as about 50 cm, and may also have a range from 15-60 cm. Importantly, the binding elements according to present application having a length ranging from 40-60 cm can be installed without severe buckling. According to European regulations, a standard insulation in a building wall structure now is about 18 cm, while the standard insulation thickness is increasing and by 2018 this will be about 30 cm. Therefore, the binding element trend is towards increasing lengths as the insulation thickness is increasing.

The term “building wall structure” refers to a wall as used in the construction industry. Typically, the wall structure may be made from layers of bricks; the term may also refer to concrete or wood or like structures.

In one embodiment of the present invention the tensile strength of binding element is at least 100 N/mm², preferably in range of 100-125 N/mm². The tensile strength of a test specimen is the breaking load of the test specimen per unit of unstrained cross-sectional area. The tensile strength is expressed in newtons per square millimeter or megapascals.

In one embodiment of the present invention the binding element is in accordance with regulations specified in NEN-EN 846.

In one embodiment of the present invention the shape of said elongated steel element is selected from the group consisting of I-profile, H-profile, round, flat, square, rectangular, triangular, trapezoidal, oval, half-round and mixtures thereof. In another embodiment of the present invention the elongated steel element is an elongated steel wire having a diameter ranging from 2 mm to 5 mm.

In one embodiment of the present invention the thermoplastic coating is selected from a group consisting of polyolefins, foamed thermoplastic resins, thermoplastic polyurethane. Examples of suitable thermoplastic materials are: polyethylene (PE), polypropylene (PP), polystyrene (PS), polyethylene terephthalate (PET), polyethylene napthalate (PEN), polybuteen terephthalate (PBT) polyvinylchloride (PVC), polyamide (PA), polyester (PES), polyimide (PI), polycarbonate (PC), styrene acrilonitryl (SAN), acrylonitril-butadiene-styrene (ABS), thermoplastic polyurethane (TPU), thermoplastic polyolefins (TPO), thermoplastic copolyetheresters, copolymers of these polymers or similar materials.

In one embodiment of the present invention the elongated steel element is covered with an intermediate metallic coating. The intermediate metallic coating is a copper, copper alloy, zinc, zinc alloy, nickel, nickel alloy, tin or tin alloy or combinations thereof. Another preferred method is to coat the elongated steel element by running it through a bath of molten metal. This method is particularly suited to coat the elongated steel element with zinc (hot dip galvanising) or a zinc alloy—such as zinc aluminium alloy like Bezinal® coated wire of Bekaert—or copper or a copper alloy or tin. FIGS. 3 to 6 depict certain embodiments of the present invention showing the intermediate metallic coating (23).

In a further embodiment the elongated steel element is a steel wire and diameter of said steel wire is at least 0.2 mm and the thickness of intermediate metallic coating is at least 20% of the steel wire thickness. In one embodiment the total diameter of the steel wire with the coating is lower than 5 mm. In a preferred embodiment the total diameter of the steel wire with the coating is lower than 3 mm, and may vary between 0.60 mm and 1.60 mm.

In yet a further embodiment the steel wire is a low carbon steel wire with carbon content below 0.20 wt %. In this embodiment the steel wire has preferably a carbon content ranging between 0.04 wt % and 0.20 wt %. The complete composition of the wire rod may be as follows: a carbon content of 0.06 wt %, a silicon content of 0.166 wt %, a chromium content of 0.042 wt %, a copper content of 0.173 wt %, a manganese content of 0.382 wt %, a molybdenum content of 0.013 wt %, a nitrogen content of 0.006 wt %, a nickel content of 0.077 wt %, a phosphorus content of 0.007 wt %, a sulfur content of 0.013 wt %.

In a further embodiment the elongated steel element is a stainless steel alloy wire and diameter of said stainless steel alloy wire is at least 0.2 mm and the thickness of intermediate metallic coating is at least 20% of the steel wire thickness. The stainless steel alloy is selected from a group consisting of 201, 202, 301, 302, 303, 303Se, 304; 304L, 309S, 310S, 306, 316L, 317, 317L, 321, 329, 330, 347, 409, 410, 416, 416Se, 420, 430, 440C, 442, 904L, 17-4 PH, 17-7PH, 2205, CA-6NM, CA-15, CA-40, CF-3, CF-3M, CF-8, CF-8M, CH-20, CK-20, HF, HH, HK.

In another embodiment the steel wire is a high carbon steel wire with a carbon content above 0.25 wt % and lower than 1.0 wt %. The steel wire is highly mechanically deformed.

In one embodiment of the present invention an adhesion layer is at least partially applied between the elongated steel element and the thermoplastic coating, the adhesion layer comprises a compound selected from organo functional silanes, organo functional titanates, and organo functional zirconates.

The adhesion layer is selected from organo functional silanes, organo functional titanates and organo functional zirconates which are known in the art for said purpose. Preferably, but not exclusively, the organo functional silanes are selected from the compounds of the following formula:

Y—(CH₂)n-SiX3

wherein: Y represents an organo functional group selected from —NH2, CH₂═CH—, CH₂═C(CH₃)COO—, 2,3-epoxypropoxy, HS— and, Cl
—X represents a silicon functional group selected from —OR, —OC(═O)R′,
—Cl wherein R and R′ are independently selected from C1 to C4 alkyl, preferably —CH₃, and —C₂H₅; and n is an integer between 0 and 10, preferably from 0 to 10 and most preferably from 0 to 3.

The organo functional silanes described above are commercially available products.

The thickness of thermoplastic material ranges from 150 μm to 1000 μm, preferably from 250 μm to 500 μm.

In one embodiment of the present invention the thermoplastic material may further comprise coloring agents. The advantage of such coloring agent is to impart color to the portion of binding element which is still exposed during construction of wall and such color may also have glow in the dark agents which can be used for safety purposes so that these protruding binding elements are visible in the dark. Some examples of such coloring agents are color masterbatches which impart color to plastics.

In one embodiment of the present invention the thermoplastic material may further comprise flame retarding agents. Some examples of such flame retarding are bishydroxydeoxybenzoin, bromine or non-halogenated agents that are added to thermoplastic.

The term “thermal conductivity” is defined as the quantity of heat transmitted through a unit thickness in a direction normal to a surface of unit area, due to a unit temperature gradient under steady state conditions. Thermal conductivity λ is expressed in W/Km. Some values: steel has a HTC of 50 W/Km; stainless steel of 15 W/Km. In one embodiment of the present invention the binding element has thermal conductivity below 5 W/Km, preferably below 2 W/Km, more preferably below 1 W/Km.

In one embodiment of the present invention at least a portion or the ends of the binding element has a surface texture selected from a group consisting of taper, indentation, serration, thread, ribbed and combinations thereof. Such a surface provides better anchorage to the wall structure. For instance an indentation in the ends of the binding element improves anchorage to the cement mortar embedded in the masonry joint during brick wall construction. Such surface texture may be imparted on the elongated steel element by passing through surface textured rollers.

In one embodiment of the present invention at least a portion or the ends of said binding element are bent at angle ranging from 20° to 90° with respect to the axis of the middle portion of the said binding element. FIGS. 3 and 4 illustrate a structure with “L-shape” at two end sides.

In one embodiment of the present invention at least a portion or the ends of said binding element are crimped. FIGS. 5 and 6 show such a crimped or wavy structure. The advantage of this form is to provide better anchorage of the binding agents to the wall structure.

In another embodiment of present invention, a portion or one end of said binding element is bent at angle ranging from 20° to 90° with respect to the axis of the middle portion of the said binding element and the other portion or end is crimped or waved. As an example, such a structure is shown in FIG. 7.

In still another embodiment of present invention, a portion or one end of said binding element has a surface texture selected from a group consisting of taper, indentation, serration, thread, ribbed and combinations thereof and the other portion or end is crimped or waved. As an example, such a structure is shown in FIG. 8.

In still another embodiment of present invention, at least one crimped or waved portion is introduced in-between the two ends of said binding element. As an example, such a structure is shown in FIG. 9.

In yet another embodiment of present invention, at least a portion or the ends of said binding element are firstly bent at angle ranging from 20° to 90° with respect to the axis of the middle portion of the said binding element, and then the bent portion is further bent at angle ranging from 20° to 90° with respect to the axis of the bent portion. As an example, FIG. 10 shows such a bent structure at one end of said binding element.

Claims

1-15. (canceled)

16. Use of a binding element for a building wall structure of concrete or like composition, wherein said binding element comprises an elongated steel element coated with a thermoplastic material, and wherein the coated thermoplastic material has a uniform thickness on each straight portion of the elongated steel element.

17. Use of the binding element of claim 16, wherein shape of said elongated steel element is selected from the group consisting of I-profile, H-profile, round, flat, square, rectangular, triangular, trapezoidal, oval, half-round and mixtures thereof.

18. Use of the binding element according to claim 16, wherein said elongated steel element is an elongated steel wire having a diameter ranging from 2 mm to 5 mm.

19. Use of the binding element according to claim 16, wherein said elongated steel element has a minimum tensile strength of at 100 N/mm2 and a length ranging from 40 cm to 60 cm.

20. Use of the binding element according to claim 16, wherein said thermoplastic material is selected from a group consisting of polyolefins, foamed thermoplastic resins, thermoplastic polyurethane.

21. Use of the binding element according claim 16, wherein an adhesion layer is at least partially applied between the elongated steel element and the thermoplastic coating, the adhesion layer comprises a compound selected from organo functional silanes, organo functional titanates, and organo functional zirconates.

22. Use of the binding element according to claim 16, comprising a thermoplastic coating in its entire length of said elongated steel element, and wherein said binding element has two edges and the thermoplastic material is not coated thereon.

23. Use of the binding element according to claim 16, said thermoplastic coating comprises a coloring agent and/or a flame retardant agent.

24. Use of the binding element according to claim 16, wherein thickness of said thermoplastic coatings ranges from 150 μm to 1000 μm.

25. Use of the binding element according to claim 17, wherein said elongated steel element is covered with an intermediate metallic coating and wherein said intermediate metallic coating is selected from a group consisting of copper, copper alloy, zinc, zinc alloy, nickel, nickel alloy, tin or tin alloy or combinations thereof.

26. Use of the binding element according to claim 16, wherein at least a portion or the ends of said binding element has a surface texture selected from a group consisting of taper, indentation, serration, thread, ribbed and combinations thereof.

27. Use of the binding element according to claim 16, wherein at least a portion or the ends of said binding element are bent at angle ranging from 20° to 90° with respect to the axis of the middle portion of the said binding element.

28. Use of the binding element according to claim 16, wherein at least a portion or the ends of said binding element are crimped or waved.

29. A building wall structure comprising an inner wall, an outer wall spaced from said inner wall and provided with at least one insulation layer(s) in between, at least one binding element as defined in claim 16 interconnecting said outer wall and inner wall through the insulation layer, wherein ends of said binding element are fixed to the said outer wall and said inner wall respectively and wherein middle portion of said binding element is in contact with the said insulation layer(s).

30. The building wall structure of claim 29, wherein the length of the said middle portion of said binding element equates the spacing between the said outer wall and inner wall.