WO2003023162A1 - Structural element, in particular for the building industry - Google Patents
Structural element, in particular for the building industry Download PDFInfo
- Publication number
- WO2003023162A1 WO2003023162A1 PCT/IT2002/000581 IT0200581W WO03023162A1 WO 2003023162 A1 WO2003023162 A1 WO 2003023162A1 IT 0200581 W IT0200581 W IT 0200581W WO 03023162 A1 WO03023162 A1 WO 03023162A1
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- Prior art keywords
- sheet
- structural element
- element according
- transparent
- strip
- Prior art date
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Classifications
-
- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
- E04C3/00—Structural elongated elements designed for load-supporting
- E04C3/02—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces
- E04C3/28—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces of materials not covered by groups E04C3/04 - E04C3/20
- E04C3/285—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces of materials not covered by groups E04C3/04 - E04C3/20 of glass
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B17/00—Layered products essentially comprising sheet glass, or glass, slag, or like fibres
- B32B17/06—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material
- B32B17/10—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin
- B32B17/10005—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing
- B32B17/10009—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing characterized by the number, the constitution or treatment of glass sheets
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B17/00—Layered products essentially comprising sheet glass, or glass, slag, or like fibres
- B32B17/06—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material
- B32B17/10—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin
- B32B17/10005—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing
- B32B17/10165—Functional features of the laminated safety glass or glazing
- B32B17/10293—Edge features, e.g. inserts or holes
- B32B17/10302—Edge sealing
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B17/00—Layered products essentially comprising sheet glass, or glass, slag, or like fibres
- B32B17/06—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material
- B32B17/10—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin
- B32B17/10005—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing
- B32B17/10165—Functional features of the laminated safety glass or glazing
- B32B17/10311—Intumescent layers for fire protection
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B17/00—Layered products essentially comprising sheet glass, or glass, slag, or like fibres
- B32B17/06—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material
- B32B17/10—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin
- B32B17/10005—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing
- B32B17/10165—Functional features of the laminated safety glass or glazing
- B32B17/10366—Reinforcements of the laminated safety glass or glazing against impact or intrusion
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B17/00—Layered products essentially comprising sheet glass, or glass, slag, or like fibres
- B32B17/06—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material
- B32B17/10—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin
- B32B17/10005—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing
- B32B17/1055—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing characterized by the resin layer, i.e. interlayer
- B32B17/10761—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing characterized by the resin layer, i.e. interlayer containing vinyl acetal
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B17/00—Layered products essentially comprising sheet glass, or glass, slag, or like fibres
- B32B17/06—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material
- B32B17/10—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin
- B32B17/10005—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing
- B32B17/1055—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing characterized by the resin layer, i.e. interlayer
- B32B17/1077—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing characterized by the resin layer, i.e. interlayer containing polyurethane
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B27/00—Layered products comprising a layer of synthetic resin
- B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
-
- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
- E04C3/00—Structural elongated elements designed for load-supporting
- E04C3/02—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces
- E04C3/29—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces built-up from parts of different material, i.e. composite structures
Definitions
- the present invention relates to a structural element, in particular for the building industry, made of transparent material and intended for the construction, for example, of a pillar, a beam, a lintel, an arch or similar elements all offering a notable degree of safety.
- the present invention relates to structural elements, including large-size elements, made mainly of glass.
- the individual sheets which form the glass parts of buildings are positioned and supported by structural elements, such as pillars, beams, trusses, ties and struts which are intended to absorb and oppose practically all the loads and are mostly made from traditional materials such as metal, brick or stone, wood or reinforced concrete .
- this effect can be heightened in the case of large covering surfaces, the manufacture of which requires large-size structural elements able to withstand bending stresses .
- the manufacture of these structural elements from glass poses several problems.
- Table 1 shows the typical values of these properties :
- Glass is an element which has a high hardness factor, but is very fragile. Since it is fragile, a pulsed stress produces a fracture or crack with the consequent separation of parts and risk of the structure collapsing. Moreover, the formation of a crack, even small in size (microscopic crack) results in the formation of concentrated local stresses which may be very considerable in size, even where the glass is subject to medium-range stresses which are entirely compatible with its strength. This phenomenon is particularly evident in the region of those glass parts which are subject to tensile stresses. As is well-known, microscopic cracks are typically inevitably caused by operations involving cutting of the glass into sheets.
- the cut edge even if it is smoothed afterwards, has in fact a leading edge with microscopic cracks in which the stresses - while widely admissible if uniformly distributed as in the case of tougher materials - are concentrated at the apex of the cracks and may suddenly reach values higher than the strength of the material , therefore causing fracturing thereof .
- the fracture progresses in two successive stages: during a first stage, which is referred to as “subcritical propagation” stage, there is a slow propagation of the crack to a size which is called “critical size” dependent upon the material and the stress, upon reaching of which catastrophic fracturing starts; and during a second stage, which is referred to as “catastrophic propagation” stage, the fracture spreads with a speed of propagation equivalent to a few metres per second . From scientific literature it is also known how the environmental humidity greatly favours the subcritical propagation of the fracture.
- the critical size of the crack is equivalent to: (K ⁇ c /Y ⁇ ) .
- K ⁇ c is defined as the critical stress intensification factor, is a property of the material and in the case of soda-lime glass is equal to about 0.75 MPaVm ; Ki th is defined as the stress intensification factor, i.e. the threshold below which there is no subcritical propagation of the defect, is a property of the material and in the case soda-lime glass is equal to about 0.2 MPaVm.
- the currently known manufacturing technology applied to glass elements takes into account the possibility of formation of these microscopic cracks and bases the dimensions of the said elements thereon, irrespective as to whether or not they perform structural functions, envisaging a suitable safety coefficient, on a scale up to 10, aimed at ensuring the presence of loads in the structure of the glass which are sufficiently small to avoid entering the subcritical propagation range of the flaws.
- This design approach although undoubtedly effective in the case of self-supporting or non load-bearing glass, undoubtedly has safety shortcomings in the case where the glass element is intended to perform a structural function so as to withstand loads which are static or cyclical over time.
- fragment material is understood as meaning a material which, when subjected to an increasing compressive or tensile stress, does not have a plastic, but only an elastic behaviour range followed by breakage:
- the expression "tough material” is understood as meaning a material which, when subjected to an increasing compressive or tensile stress, has a plastic behaviour range before breakage;
- multilayer element is understood as meaning an element consisting of a plurality of sheet- like elements arranged in parallel, alongside each other, with or without the arrangement in between them of other materials such as adhesives and/or heat-resistant agents.
- the multilayer element thus obtained has, as is known, optimum properties in respect of resistance to shattering and breakage caused by impacts, but does not solve the abovementioned drawbacks which arise for each individual sheet-like element which forms the multilayer element .
- the technique of toughening the multilayer element by means of the arrangement, in between, of a sheet-like element of tough transparent plastic material, generally polycarbonate, is also known.
- the toughening internal layer adheres to the glazed surfaces, joining them integrally together.
- an incipient fracture in the glass supporting the polycarbonate - this latter material as is known, being tough - the multilayer element still retains sufficient mechanical properties to provide a residual resistance, preventing sudden collapse of the multilayer structure itself.
- the toughening action of the polycarbonate intervenes solely when all the sheets are damaged, and therefore the function of the polycarbonate layer is only that of ensuring an adequate degree of safety so that the multilayer structure does not collapse suddenly, allowing it to continue withstanding a load.
- the American Patents USA 4190698 and USA 5565273 describe a method for manufacturing elements with fire and high-temperature resistance properties, consisting of a plurality of glass sheets having arranged in between them an intumescent compound based on hydrated alkaline polysilicates with a molar ratio Si0 2 /Me 2 0 greater than 3.
- the hydrated alkaline polysilicate forms a foam which retains the fragments of glass and which, incorporating a considerable quantity of gas, has a high resistance to heat transmission through conduction or irradiation.
- the overall strength of the entire structure is obtained by simply adding together the respective strengths of the individual layers.
- the flexural rigidity which is defined as the product of the value of the elastic modulus multiplied by the value of the moment of inertia of the area of the structure in the bending plane, is obtained by adding together the flexural rigidity values of the individual sheet-like layers .
- the glass multilayer structure solutions described briefly hitherto are intended mainly for the construction of self-supporting or non load-bearing glass walls and not for the construction of structural elements intended to support loads .
- Mathias Kutterrer describes the construction of hollow box-like cross-sections using a greater quantity of material in the zone which is subject to tensile stress.
- the glass effectively withstands compression, but in view of its fragility is not very resistant to tensile stresses. Therefore, in accordance with this study, the glass is combined with a separate element or with a separate strong structure resistant to tensile stresses, so as to improve partly the distribution of the tensile loads over the whole multilayer structure.
- the glass is subject to a smaller load than the load which would affect it if no combined solution were to be adopted.
- the tensile forces which act on the beam are transmitted to the element or to the additional structure, while the glass continues to absorb the compressive forces since it is able to maintain its compressive strength even when damaged.
- the tensile stresses, which are absorbed by the element or by the additional structure resistant to tensile stress, are not transmitted to the multilayer glass structure but transmitted directly to the beam support plane . According to this known art, in particular the following different embodiments are possible:
- the glass elements rest, without adhering, on the additional elements which are resistant to tensile stress and which therefore transmit the corresponding stresses to the support plane.
- a common drawback of these known embodiments is the need to provide constraining devices in order to allow the tensile elements to withstand all the tensile forces and the associated bending moments to which they may be subject.
- the patent WO0076763 describes the construction of a multilayer glass element with steel cables inserted between the sheets which form the multilayer element and which are arranged equidistant from each other and extend over the whole surface of the said sheets .
- a primary object of the present invention is therefore that of eliminating the drawbacks of the known art mentioned above by providing a structural element, in particular for the building industry, with an improved flexural rigidity and safety characteristics.
- Another object is that of providing toughened, transparent, structural elements without the addition, between the sheets of glass, of one or more tough and transparent polymer sheets .
- Another object is to provide transparent structural elements which are protected against the subcritical propagation of the microscopic cracks, which is caused or favoured by humidity.
- a further object is to provide transparent structural elements which are particularly light and able to best exploit the mechanical characteristics of glass .
- a particular object of the invention is to provide transparent structural elements with reduced production and assembly costs .
- a structural element in particular for the building industry, comprising at least one sheet-like portion of transparent material provided with a peripheral edge, characterized in that it also comprises at least one strip-like portion integrally adhering to at least one section of the peripheral edge of the sheet-like portion so as to increase the flexural rigidity and/or the toughness of the sheet-like portion itself.
- FIG. 1 shows a perspective view of a first example of embodiment of a transparent structural element according to the present invention, subject to a bending stress;
- FIG. 2 shows a top plan view of the example of embodiment according to FIG. 1;
- FIG. 3 shows a cross-section along a plane, as indicated by the line Z-Z, perpendicular to the plane of inflection of the example of embodiment according to FIG.
- FIGS. 4 ad 5 show the detail of some embodiments of the strip-like element
- FIG. 6 shows a perspective view of a second example of embodiment of a transparent structural element according to the present invention, subject to a bending stress
- FIG. 7 shows a top plan view of the example of embodiment according to FIG. 6;
- FIG. 8 shows a cross-section along a plane, as indicated by the line V-V, perpendicular to the plane of inflection of the example of embodiment according to FIG.
- FIG. 9 shows a perspective view of a third example of embodiment of a transparent structural element according to the present invention, subject to a bending stress.
- FIG. 10 shows a top plan view of the example of embodiment according to FIG. 9 ;
- FIG. 11 shows a perspective view of a fourth example of embodiment of a transparent structural element according to the present invention, subject to a compressive/bending stress;
- FIG. 12 shows a front view of the example of embodiment according to FIG. 11;
- FIG. 13 shows a cross-section along the plane, indicated by the line U-U, of the example of embodiment according to FIG. 11;
- FIG. 14 shows the diagram of a horizontal or vertical structural element subject to a bending stress imparted by a uniformly distributed load
- FIG. 15 shows the diagram of a horizontal or vertical structural element according to the present invention, subject to a bending stress imparted by a uniformly distributed load.
- 1 denotes in its entirety a transparent structural element constructed in accordance with the present invention.
- the abovementioned structural element 1 may advantageously consist of a beam, a lintel, an arch or a similar element, in view of the fact that, in these constructional forms, the invention in question offers the greatest advantages in terms of the improved performance with regard to mechanical behaviour.
- the structural element in question may also assume other constructional forms such as that of a transparent multilayer wall or a column, as explained in particular in the example shown in Figures 11 to 13.
- the structural element 1 generally consisting of a beam.
- the beam 1 essentially consists of a sheetlike portion 2 and a strip-like portion 3. The latter is integrally joined to at least one section of the peripheral edge 4 of the sheet-like portion 2.
- the beam 1 therefore consists of a composite structure comprising two portions 2 and 3 forming a single body.
- the sheet-like portion 2 is in turn formed by means of one or more transparent sheet- like elements 5, 5', 5 1 ', 5''' - made of glass or other transparent material such as polycarbonate - which are arranged adjacent and parallel to each other and between which first layers 6, 6 1 , 6'' of transparent adhesive are arranged.
- fixing means 7 are provided along the entire edge 4 of the sheet-like portion 2 in the region of the part 2' of the latter which is subject to tensile stress.
- These means advantageously consist of a second layer 7 of adhesive which is made to adhere to the strip-like portion 3.
- the latter preferably consists of one or more strips
- the thickness of the layers of adhesive is preferably between 0.1 and 2 mm (this latter limit value in particular for the layer of polyvinyl butyral) .
- the adhesive is of the transparent type based on polyvinyl butyral .
- the intumescent transparent adhesive has a thickness preferably between 0.1 and 3 mm.
- the strips 8 may be made of homogeneous metallic material such as aluminium, steel or titanium, or non- metallic material such as carbon fibre or Kevlar, or a composite material .
- the composite material is a polymer matrix fibre-reinforced with long or short fibres.
- the fibres may be of an inorganic nature, such as boron or steel fibres, or of an organic nature, such as carbon fibres or Kevlar, or a combination thereof .
- these fibres are organised in the form of fabrics, matting or fibrous structures of the type known by the technical term "mat” (short fibres mixed in a resin matrix paste) .
- the strip-like portion 3 may consist of a single layer (composed for example of one or more strips of the abovementioned type) or several layers of different material.
- layers of "tough” material arranged so as to adhere to the edge 4 of the element 2 , and layers of "rigid” material arranged externally, will be present .
- the example of embodiment of the strip-like element shown in FIG. 3 consists of a layer 8 of tough material and a layer 8' of rigid material which are joined integrally together by means of the third adhesive layer
- FIG. 4 shows an example of embodiment in which the strip-like element 3 consists of a single strip 10 of tough or rigid material .
- the strip-like element 3 consists of a layer 11 of tough material, a layer 12 of rigid metallic material and a layer 13 of rigid material consisting of fibre- reinforced polymer matrix which are joined integrally together by means of the third layers 9 and 9 ' of adhesive .
- the rigid layers consist of material having a modulus of elasticity greater than that of glass, equal to 70 GPa.
- the tough layers consist of material having K ⁇ c greater than 0.75 MPaVm.
- the strip-like portion 3 is integrally fastened to the sheet-like portion 2 of the beam 1 and not to the support plane thereof .
- the devices A, A 1 for constraining the beam 1 are simple supports and therefore are unable to oppose stresses having directions different from the perpendicular direction.
- FIG. 14 shows in schematic form a beam simply resting under the weight of a uniformly distributed load Q and having the cross-section schematically shown in 14b.
- FIG. 14d shows the bending moment diagram and 14c the stress diagram. Being an isotropic material, there is an even distribution of the compressive and tensile stresses separated by the neutral axis indicated by the line X-X.
- FIG. 15 shows in schematic form the beam according to the present invention simply resting on the two fastening devices A, A 1 and subjected to a uniformly distributed load Q 1 .
- the cross-section of the beam 1 is schematically shown in Fig. 15b.
- FIG. 15d shows the bending moment diagram
- FIG. 15c shows the stress diagram in which it can be noted how most of the tensile stress is absorbed by the strip-like portion 3 and the neutral axis indicated by the line Y-Y is clearly displaced towards the edge 4 of the part 2 ' of the sheet-like portion 2 subject to tensile stress.
- the reference number 14 indicates overall a second embodiment of a transparent structural element according to the present invention, represented by a beam subject to bending stress and essentially consisting of a sheet-like portion 15 and a strip-like portion 3 integrally joined to at least one edge 4 of the sheet-like portion 15.
- the sheet-like portion 15 consists of a plurality of sheet-like elements 16, 16', 16'', 16 ' ' ' , 16"", etc., each having a length less than the span L of the beam and arranged adjacent and parallel to each other, but staggered with respect to each other in a continuous manner in the direction of the beam length.
- the striplike portion 3 is integrally joined to the edge 4 of the sheet-like portion 15 in the region of the part 15' of the latter subject to tensile stress, by means of the second layer 7 of adhesive. This latter part 15' is defined by the stress diagram as indicated in the preceding Figure 15c.
- the stress is induced by a load P 1 acting parallel to the main plane of lie of the sheet-like portions 15 and perpendicularly with respect to the dimension of their greater extension and is opposed by the sole supports A and A' .
- the reference number 17 indicates in its entirety a third embodiment of a transparent structural element according to the present invention, also subject to bending stress. It has an arched shape and essentially consists of a sheet-like portion 18 and a strip-like portion 3 integrally joined to the edge 4 of the portion 18 subject to a tensile stress.
- the sheet-like portion 18 consists of a plurality of sheet-like element elements 19, 19', 19", 19'", 19"" .... , having an arched bottom edge and each having a length less than the span LL of the arch, being arranged adjacent and parallel to each other, but staggered with respect to each other in a continuous manner in the direction of the curved abscissa of the arch.
- the strip- like portion 3 is integrally joined to the edge 4 of the sheet-like portion 18 in the region of the part 18' of the latter subject to a tensile stress, by means of the second layer 7 of adhesive.
- the stress is induced by a load P' ' acting parallel to the main plane of lie of the sheet-like portions and substantially perpendicularly with respect to the dimension of their greater extension and is opposed by the sole supports A and A' .
- the corresponding strip-like portion 3 ensures a substantial redistribution of the stresses over the said sheet-like portion and partial transmission of the tensile stress to the said strip-like portion.
- the beam may be subject to an increasing tensile load before reaching the point of collapse and definitive breakage.
- the reference number 20 indicates overall a fourth embodiment of a transparent structural element according to the present invention, relating to a pillar which is subject to a compressive/bending stress and essentially consists of a sheet-like portion 21 and two strip-like portions 22 and 22' which are integrally joined to the edges 23 and 24 of the portion 21, parallel to the direction of the load.
- the strip-like portion 21 is composed of one or more transparent sheet-like elements which are made of glass or other transparent material such as polycarbonate and which are arranged adjacent and parallel to each other and between which first layers of transparent adhesive are arranged.
- the compressive/bending stress is induced by a load P' ' acting parallel to the main plane of lie of the sheet-like portions and parallel to the dimension of their greater extension.
- the structural element according to the present invention has been designed in particular as a beam for achieving the mechanical performance characteristics described above, it is suitable also for assuming other configurations such as the column-like configuration illustrated above, albeit distinguished by particular advantageous mechanical characteristics .
- the overall moment of inertia of the column in the bending plane is obtained by adding together the respective values of the individual sheet-like portions 21 forming the said column, each calculated as bh 3 /l2 where b indicates the thickness and h the height of the sheet-like portion 21.
- the moment of inertia of the column in the bending plane is obtained, without taking into account the rigidifying effect of the said strip-like portions 22 and 22', from bD 3 /l2 where D is the sum of the thicknesses b of the individual sheets.
- Transparent structural element subject to a bending stress consisting of glass sheets parallel to each other, 4300 mm long, 600 mm wide, 15 mm thick.
- a layer of polyvinyl butyral, 0.76 mm thick is arranged between each pair of adjacent sheets. The stress is induced by a load acting parallel to the greater plane of the sheetlike elements.
- a layer of aluminium, 10 mm thick, 62 mm wide, 4300 mm long is glued by means of a layer of epoxy adhesive such as araldite (Ciba) .
- araldite araldite
- Transparent structural element subject to a bending stress consisting of glass sheets parallel to each other, 4300 mm long, 600 mm wide, 15 mm thick.
- a layer of polyvinyl butyral, 0.76 mm thick, is arranged between each pair of adjacent sheets. The stress is induced by a load acting parallel to the greater plane of the sheet- like elements.
- a strip-like element consisting of a layer of aluminium, 5 mm thick, 62 mm wide, 4300 mm long and a layer 5 mm thick, 62 mm wide and 4300 mm long made of resin fibre-reinforced with long unidirectional carbon fibres having an elastic modulus greater than 300 GPa, is glued by means of a layer of epoxy adhesive such as araldite (Ciba) .
- the volumetric fraction of the fibres is equal to 50 per cent.
- Example 3 Composite structural element, subject to a bending stress, consisting of four series of glass sheets arranged parallel to each other, 4400 mm long, 600 mm wide.
- the first series of sheets consists, along the abscissa of the beam, of a first sheet, 1100 mm long, 600 mm wide, 15 mm thick, a second sheet 2200 mm long, 600 mm wide, 15 mm thick, a third sheet 1100 mm long, 600 mm wide, 15 mm thick;
- the second series of sheets consists, along the abscissa of the beam, of a first and a second sheet, 2200 mm long;
- the third series of sheets consists, along the abscissa of the beam, of the same elements as the first series of sheets and the fourth series of sheets consists of the same elements as the second series of sheets.
- a layer of polyvinyl butyral, 0.76 mm thick, is arranged between each adjacent series of sheets.
- a strip-like element, formed as in Example 2 is glued to the entire edge subject to tensile stress.
- Example 4
- a composite transparent structural element having an arched shape with a span of 3000 mm, subject to a bending stress consisting of four series of glass sheets parallel to each other and formed by a plurality of sheet-like elements having an arched bottom edge, each sheet having a length less than the span of the arch, arranged adjacent and parallel to each other, but staggered with respect to each other in a continuous manner in the direction of the curved abscissa of the arch.
- the first series of sheets consists, along the curved abscissa of the arch, of a first sheet 700 mm long, 600 mm wide, 15 mm thick, a second sheet 1600 mm long, 600 mm wide, 15 mm thick, and a third sheet 700 mm long, 600 mm wide, 15 mm thick;
- the second series of sheets consists, along the curved abscissa of the arch, of a first and a second sheet 1500 mm long
- the third series of sheets consists, along the curved abscissa of the arch, of the same elements as the first series of sheets and the fourth series of sheets consists of the same elements as the second series of sheets .
- a strip-like element, formed as in Example 2 is glued along the entire edge subject to tensile stress, by means of a layer of epoxy resin such as araldite (Ciba) .
- the strip-like portion 3 may be formed by bands having a width corresponding to the width of the individual sheet onto which they are joined so as to adhere.
- this solution does not reduce the bond between the individual sheets 5, 6 since preferably the strip-like portion 3 is formed by highly directed fibres able to withstand the tensile stresses solely in the direction of extension of the edge of the said sheets and not in the direction perpendicular to their thickness .
- the transparency of the structural element is not substantially modified compared to similar transparent structural elements at present commercially available, since the strip-like portion of the element according to the invention is arranged along the ordinarily ground and therefore per se less transparent edge of the structural elements of the known type. Moreover, the provision of a strip-like portion fixed to a sheet-like portion according to the present invention allows the structural elements subject to tensile stress to be positioned on simple supports.
- the flexural rigidity of the structural element may be increased as a whole.
- the critical load acting on the structure itself may be increased.
- the adhesive layer between the strip-like elements may consist of a material having intumescent properties .
- the presence of a tough layer in the strip-like portion toughens the overall structural element and renders superfluous, without affecting the safety, the presence of a sheet of tough material such as polycarbonate unnecessary in the sheet-like portion, with a consequent constructional simplification and reduction in costs.
- the strip-like portion with a tough and/or rigid layer integral with the part of the sheet- like portion subject to tensile stress since it absorbs most of the tensile stresses which are responsible for the subcritical propagation of the microscopic cracks, allows a more precise design of the structural element and therefore, without affecting the safety, allows the adoption of a decidedly lower safety coefficient .
- a further advantage consists in being able to apply the finding according to the present invention also to ready existing structures.
Landscapes
- Engineering & Computer Science (AREA)
- Architecture (AREA)
- Civil Engineering (AREA)
- Structural Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Composite Materials (AREA)
- Laminated Bodies (AREA)
- Joining Of Glass To Other Materials (AREA)
- Hydrogenated Pyridines (AREA)
- Burglar Alarm Systems (AREA)
Abstract
Description
Claims
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE60227684T DE60227684D1 (en) | 2001-09-12 | 2002-09-12 | CONSTRUCTION ELEMENT, ESPECIALLY FOR THE CONSTRUCTION INDUSTRY |
EP02798028A EP1432881B1 (en) | 2001-09-12 | 2002-09-12 | Structural element, in particular for the building industry |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
ITBS2001A000068 | 2001-09-12 | ||
IT2001BS000068A ITBS20010068A1 (en) | 2001-09-12 | 2001-09-12 | TRANSPARENT STRUCTURAL ELEMENT WITH INCREASED SECURITY |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2003023162A1 true WO2003023162A1 (en) | 2003-03-20 |
Family
ID=11440765
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/IT2002/000581 WO2003023162A1 (en) | 2001-09-12 | 2002-09-12 | Structural element, in particular for the building industry |
Country Status (6)
Country | Link |
---|---|
EP (1) | EP1432881B1 (en) |
AT (1) | ATE401472T1 (en) |
DE (1) | DE60227684D1 (en) |
ES (1) | ES2311072T3 (en) |
IT (1) | ITBS20010068A1 (en) |
WO (1) | WO2003023162A1 (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102004050214A1 (en) * | 2004-10-15 | 2006-04-27 | Bauhaus-Universität Weimar Dezernat Forschungstransfer und Haushalt | Constructional element made up of different materials for window panes has main framework made up of plastic disks which are connected in laminar manner to glass panes |
DE102007001651A1 (en) * | 2006-12-18 | 2008-06-19 | Evonik Röhm Gmbh | Composite systems using plastics in combination with other materials |
WO2009122269A1 (en) | 2008-04-03 | 2009-10-08 | Universidade Do Minho | Composite wood-glass structural panel and process for producing same |
WO2009141714A2 (en) | 2008-05-21 | 2009-11-26 | Universidade Do Minho | Combined wood-glass skeleton structure and process of producing same |
ITVI20110005A1 (en) * | 2011-01-20 | 2012-07-21 | Michel Palumbo | STRUCTURAL BUILDING ELEMENT |
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DE897755C (en) * | 1951-09-11 | 1953-11-23 | Glasbau Heinrich Hahn | Profile support |
FR2171929A1 (en) * | 1972-02-16 | 1973-09-28 | Triplex Ste Ind | Laminated safety glass - having plastic layer incorporating fibres or fabric |
DE2906259A1 (en) * | 1979-02-19 | 1980-08-21 | Schulze Herbert Dietrich Gmbh | Transparent acoustically-isolating sandwich type wall building plate - has e.g. polystyrene covers with foamed phenol!-formaldehyde! filling |
US5040352A (en) * | 1989-07-13 | 1991-08-20 | Degussa Aktiengesellschaft | Noise-protection elements of acrylic glass |
FR2676049A1 (en) * | 1991-04-30 | 1992-11-06 | Glaverbel | Curved laminated window pane and process for its manufacture |
US5219630A (en) * | 1987-02-20 | 1993-06-15 | Miller Construction Limited | Fire resistant safety glass |
EP0750079A1 (en) * | 1995-06-22 | 1996-12-27 | Saint-Gobain Vitrage | Method of manufacturing a composite structural element and article thus obtained |
DE29521460U1 (en) * | 1995-10-21 | 1997-05-07 | Röhm GmbH & Co. KG, 64293 Darmstadt | Fire-proof, transparent pane element |
US5794403A (en) * | 1995-10-21 | 1998-08-18 | Degussa Aktiengesellschaft | Fireproof transparent pane panel |
-
2001
- 2001-09-12 IT IT2001BS000068A patent/ITBS20010068A1/en unknown
-
2002
- 2002-09-12 EP EP02798028A patent/EP1432881B1/en not_active Expired - Lifetime
- 2002-09-12 AT AT02798028T patent/ATE401472T1/en not_active IP Right Cessation
- 2002-09-12 ES ES02798028T patent/ES2311072T3/en not_active Expired - Lifetime
- 2002-09-12 WO PCT/IT2002/000581 patent/WO2003023162A1/en active IP Right Grant
- 2002-09-12 DE DE60227684T patent/DE60227684D1/en not_active Expired - Lifetime
Patent Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE897755C (en) * | 1951-09-11 | 1953-11-23 | Glasbau Heinrich Hahn | Profile support |
FR2171929A1 (en) * | 1972-02-16 | 1973-09-28 | Triplex Ste Ind | Laminated safety glass - having plastic layer incorporating fibres or fabric |
DE2906259A1 (en) * | 1979-02-19 | 1980-08-21 | Schulze Herbert Dietrich Gmbh | Transparent acoustically-isolating sandwich type wall building plate - has e.g. polystyrene covers with foamed phenol!-formaldehyde! filling |
US5219630A (en) * | 1987-02-20 | 1993-06-15 | Miller Construction Limited | Fire resistant safety glass |
US5040352A (en) * | 1989-07-13 | 1991-08-20 | Degussa Aktiengesellschaft | Noise-protection elements of acrylic glass |
FR2676049A1 (en) * | 1991-04-30 | 1992-11-06 | Glaverbel | Curved laminated window pane and process for its manufacture |
EP0750079A1 (en) * | 1995-06-22 | 1996-12-27 | Saint-Gobain Vitrage | Method of manufacturing a composite structural element and article thus obtained |
DE29521460U1 (en) * | 1995-10-21 | 1997-05-07 | Röhm GmbH & Co. KG, 64293 Darmstadt | Fire-proof, transparent pane element |
US5794403A (en) * | 1995-10-21 | 1998-08-18 | Degussa Aktiengesellschaft | Fireproof transparent pane panel |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102004050214A1 (en) * | 2004-10-15 | 2006-04-27 | Bauhaus-Universität Weimar Dezernat Forschungstransfer und Haushalt | Constructional element made up of different materials for window panes has main framework made up of plastic disks which are connected in laminar manner to glass panes |
DE102007001651A1 (en) * | 2006-12-18 | 2008-06-19 | Evonik Röhm Gmbh | Composite systems using plastics in combination with other materials |
WO2008074524A1 (en) * | 2006-12-18 | 2008-06-26 | Evonik Röhm Gmbh | Composite support systems using plastics in combination with other materials |
WO2009122269A1 (en) | 2008-04-03 | 2009-10-08 | Universidade Do Minho | Composite wood-glass structural panel and process for producing same |
WO2009141714A2 (en) | 2008-05-21 | 2009-11-26 | Universidade Do Minho | Combined wood-glass skeleton structure and process of producing same |
ITVI20110005A1 (en) * | 2011-01-20 | 2012-07-21 | Michel Palumbo | STRUCTURAL BUILDING ELEMENT |
Also Published As
Publication number | Publication date |
---|---|
ATE401472T1 (en) | 2008-08-15 |
DE60227684D1 (en) | 2008-08-28 |
ES2311072T3 (en) | 2009-02-01 |
EP1432881B1 (en) | 2008-07-16 |
ITBS20010068A1 (en) | 2003-03-12 |
EP1432881A1 (en) | 2004-06-30 |
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