• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    Flat beam with improved fire resistance for steel-concrete slabs and their manufacturing process. Beam (10) (IFP-SFB) for steel-concrete slabs comprising: a profile (20) of I-steel (double T), double U (] [or []) or H; a steel sheet (40) attached to the lower wing (30) of the profile and with a width greater (W1) than the width (W2) of the lower wing (30) to which it is attached; a cavity formed between the lower wing (30) and the sheet (40); and an insulating layer (50), disposed inside the cavity and formed non-combustible insulating material, with a density of 150-600 kg/m3, a conductivity of less than 0.11 W/mK at 600ºC and a specific heat exceeding 1,000 J/kg.K. (Machine-translation by Google Translate, not legally binding)
    公开号:ES2732719A1
    申请号:ES201930438
    申请日:2019-05-17
    公开日:2019-11-25
    发明作者:García Manuel Luis Romero；Pérez Antonio Hospitaler；Gabarda Vicente Albero；Capilla Ana Espinós；Mercé Enrique Serra
    申请人:Universidad Politecnica de Valencia；
    IPC主号:
    专利说明:

    [0001] FLAT BEAM WITH IMPROVED FIRE RESISTANCE FOR STEEL FORGINGS-
    [0002]
    [0003] FIELD OF THE INVENTION
    [0004]
    [0005] The present invention belongs to the technical construction sector, for example and without limitation, to the construction of industrial, commercial and / or residential buildings.
    [0006]
    [0007] More particularly, the invention relates to a beam intended for use in a steel-concrete floor, of a flat type called "slim-floorTshallow-floor". This type of floor is characterized by the fact that the beams used are embedded in the floor of the floor avoiding slips. The invention also relates to a method of manufacturing said beam for steel-concrete slabs with flat beam with improved fire resistance.
    [0008]
    [0009] STATE OF THE TECHNIQUE
    [0010]
    [0011] Steel-concrete beam floor slabs of the slim-floor type (“flat floor” in English), formed by steel beams embedded in the floor slab, are increasingly used in building construction because they allow a reduction of the total floor slab, in comparison with other types of floor slabs of the current state of the art such as, for example, slabs formed by off-hook mixed beams. The flat slabs of the slim-floor steel-concrete beam also allow to increase the useful space between the slabs (in comparison with the slabs of the rafters) and facilitate the installation of technical equipment below said slab.
    [0012]
    [0013] There are several types of flat beams used in slabs of the slim-floor type. Among them, the most common are the beams called SFB (Slim Floor Beam, "Flat Beam", in English) marketed by the company Arcelor Mittal. Said SFB beams are characterized in that they comprise a conventional beam, with a profile in I (double T), double U (] [or []) or in H, which is welded, in its lower part, a metal sheet of greater width than the lower wing of the beam.
    [0014] Another type of beams commonly used in slabs of the slim-floor type are the beams called IFB (Integrated Floor Beam, "Beam integrated in the floor slab", in English) also marketed by the company Arcelor Mittal. This type of beams have 1 / 2 profile in I (double T) or H and have a welded metal sheet in the lower or upper part. Result that the lower wing of the beam has a width greater than the upper wing. Another example of IFB beam is the mixed beam asymmetric called “Asymmetríc Slimflor Beam” ® (ASB), marketed by the company Tata Steel, very similar to the IFB beam of Arcelor Mittal.
    [0015]
    [0016] In the flat-forged steel-concrete floor slabs, in addition to the steel beams, other elements such as precast, reinforced or prestressed concrete slabs or pre-slabs, prestressed alveolar slabs, pre-assembled reinforced or prestressed concrete joists are also embedded or executed “in situ”, metal joists or collaborating steel plates, in addition to the tie, suspension or longitudinal reinforcement reinforcements (in English, “rebars”) designed to improve the mechanical capacity of the slab. Likewise, it is usual to add a top slab of concrete poured on site (in situ) where the negative reinforcement and the distribution reinforcement are housed, to ensure the monolithism of the slab.
    [0017]
    [0018] The requirements that must meet the flat beams of use in the slabs of steel-concrete slim-floor in permanent or transient situation are included in Eurocode 4 part 1 1 (EN 1994-1-1: 2004) and for accidental fire situation the requirements established by Eurocode 4 part 1-2 (EN 1994-1-2: 2005), the main European regulations for this purpose, edited by CEN, European Committee for Standardization.
    [0019]
    [0020] In spite of the advantages of the floor slabs of the slim-floor type mentioned above, in the state of the art there are still no beams designed specifically for use in floor slabs of the "slim-floor" type and which also have resistance properties to fire (R) improved.
    [0021]
    [0022] Within the sector, procedures have been developed to increase the fire resistance of structural elements, such as beams, floor slabs and other construction elements.
    [0023]
    [0024] Said fire resistance (R) is measured quantitatively in minutes of exposure to a normalized fire after which the structural element will reach collapse. The methodology of Evaluation of this fire resistance of structural elements is based on three different models: A fire model, a thermal model for heat transmission and a mechanical behavior model for high temperature materials.
    [0025]
    [0026] The fire model is responsible for reproducing and / or simulating the behavior of the fire. The simplest fire models consist of nominal temperature-temperature curves that reproduce the evolution of the temperature in the enclosure that produces the fire. The standard time-temperature curve (ISO834-1: 1999) of Article 3.2.1 of EN1991-1-2: 2002, edited by CEN (European Committee for Standardization), and included in the resistance test standard to fire EN1363-1: 2012 is an example of this type of fire model, which reproduces the evolution of the temperature of a gas in an enclosure, during a fire. There are also other types of more advanced fire models that take into account aspects of conservation of mass and energy, such as zone models or field models based on computational fluid dynamics (in English, Computational Fluid Dynamics, CFD) .
    [0027]
    [0028] The heat transfer thermal model analyzes the evolution of the temperature along the structural element, for a given fire model. The thermal model can be both a simplified or approximate model, and an advanced model based on numerical models (finite elements, finite differences, etc.).
    [0029]
    [0030] Finally, the mechanical behavior model at high temperatures analyzes the evolution of the mechanical capacity of the structural element taking into account the reduction of the mechanical properties suffered by structural materials such as steel and concrete at high temperatures. As with the two previous models, there are simplified high-temperature mechanical behavior models, such as those provided in Annex B of EN1992-1-2: 2004 and advanced models based on numerical methods (finite elements, finite differences , etc.).
    [0031]
    [0032] The procedures for increasing the fire resistance already known, of the prior art, contemplate the application of a layer of insulating material on the outer surface of the structural elements, which in case of fire are exposed to high temperatures. Thus, the interposition of an insulating material between said element structural and the area of an enclosure that can be subjected to a fire, significantly alters the evolution of the temperatures in the structural element during the course of a possible fire, so that the mechanical capacity of said structural element and therefore its resistance to Fire will be preserved for longer.
    [0033]
    [0034] Some insulating materials commonly used in these layers are projected insulating mortars such as plaster, mineral wool, vermiculite or perlite mortars. The use of intumescent paints on metallic elements is also very common. Another alternative would be the provision of insulating materials.
    [0035]
    [0036] Intumescent paints are characterized by being exposed to high temperatures usual in a fire, they tend to swell, due to the effect of a foaming agent that acts as a thermal protection layer.
    [0037]
    [0038] A disadvantage of the procedures for increasing the fire resistance known above is that the layers of material applied are exposed to external environmental agents, which can cause deterioration of their physical-chemical properties over time. For this reason, both the layers of material based on insulating mortars, and those based on intumescent paints, must periodically undergo revision and / or maintenance operations.
    [0039]
    [0040] Thus, the insulating mortars can lose their adhesion with the passage of time, being able to get rid of the building element they protect. To prevent this from happening, it is necessary to apply new repair layers of these materials from time to time. Intumescent paints also deteriorate over time, so it is also necessary to periodically apply new maintenance layers.
    [0041]
    [0042] In view of the above, it would be desirable, therefore, to develop beams specifically designed for use in flat concrete steel slabs that incorporate elements intended to increase their fire resistance and that do not need to be subjected to maintenance operations, facilitating and simplifying in turn, its rapid commissioning and eliminating or reducing passive protection application operations to the elements exposed to the action of fire.
    [0043] DEFINITIONS
    [0044]
    [0045] Throughout the present specification it should be understood that a "flat slab of concrete steel of the slim-floor type", is all that forged made from steel beams that are embedded or integrated in the edge of the slab and that meets, in addition, with the criteria established by part 1-1 and part 1-2 of Eurocode 4 (EN 1994-1-1: 2004, EN1994-1-2: 2005), "Design of Composite Steel and Concrete Structures" ( Design of Composite Steel and Concrete Structures), edited by CEN, European Committee for Standardization, in Brussels in 2004 and 2005.
    [0046]
    [0047] Also, in the present specification the expression "high temperatures" refers to the range of temperatures that structural elements may experience in case of fire. These high temperatures are within the ranges contemplated by the standard time-temperature curve (ISO834 -1: 1999) provided by Article 3.2.1 of EN1991-1-2: 2002, edited by CEN (European Committee for Standardization) and included in the fire resistance test standard EN1363-1: 2012 .
    [0048]
    [0049] On the other hand, it should be understood that a "non-combustible" material is that material that meets all the requirements corresponding to group A1 or A2-s1d0 contemplated by the European norm for reaction to fire EN13501-1: 2002, edited by CEN, Committee European for Standardization.
    [0050]
    [0051] It should also be understood that "structural steel" is that steel that has the thermal and mechanical properties provided by parts 1-1 and 1-2 of Eurocode 4 (EN 1994-1-1: 2004, EN1994-1-2: 2005) , "Design of Composite Steel and Concrete Structures” (Edited by Composite Structures of Steel and Concrete), edited by CEN, European Committee for Standardization, in Brussels in 2004 and 2005. Structural steel is understood as all those included in the standards EN 10025-1: 2004 and EN 10088-1: 2005, the latter in the case of stainless steels.
    [0052]
    [0053] Finally, it should be understood that, in the present specification, the "lower part" of a construction element is that portion of the element located within the intrados of the wrought. On the contrary, the "upper part" of a construction element is that portion of the element located above the floor. Also, by "longitudinal" direction of a beam or construction element, it should be understood that mention is made of that predominant direction following the beam guideline [ie, for example, on an SFB beam of profile I, the direction perpendicular to the section plane of said profile I (transverse plane)]. Logically, it should also be understood that the term "transverse" refers to a plane perpendicular to the longitudinal direction.
    [0054]
    [0055] OBJECT OF THE INVENTION
    [0056]
    [0057] In order to address the problems and disadvantages existing in the state of the art mentioned above, the invention provides, according to a first aspect thereof, a flat beam with improved fire resistance for steel-concrete slabs comprising:
    [0058]
    [0059] - a profile, laminated or reinforced, of I-shaped steel (double T), double U (] [or []) or H, with at least one wing.
    [0060] - a steel sheet attached to the lower wing of said profile, the width of the steel sheet being greater than the width of the lower wing to which it is attached;
    [0061]
    [0062] said beam being characterized because it also comprises:
    [0063]
    [0064] - a cavity, preferably a closed cavity, formed between said wing and the steel plate; Y
    [0065] - an insulating layer, arranged inside the cavity and formed by at least one non-combustible material, with a density in the range of 150-600 kg / m3, a conductivity of less than 0.11 W / mK at 600 ° C and a specific heat exceeding 1,000 J / kg.K.
    [0066]
    [0067] The combination of different physical properties of the insulating layer according to the invention has been suitably chosen so that said layer, in addition to significantly slowing down the heat transmission, is also flexible and resistant. This allows said insulating layer to be able to accompany possible deformations of the profile such as those that may appear, for example, in case of fire.
    [0068]
    [0069] This technical characteristic supposes an important difference with respect to the mortars projected of the prior art used in the procedures to increase the fire resistance, since said materials, after setting and hardening, exhibit a fragile behavior.
    [0070]
    [0071] On the other hand, the insulating layer of the beams according to the present invention must necessarily be confined in the cavity formed between the profile and the sheet.
    [0072]
    [0073] In view of this, intumescent paints of the prior art could also not be used as insulating layers of the beams according to the present invention since, as seen above, said paints base their fire protection effect on which they are provided with a foaming agent, which expands when the temperature exceeds a certain threshold value, generating a thermal protection layer. Therefore, the cavity, preferably the closed cavity, is of constant volume (within the limits of the expansion and contraction of the temperature-dependent steel) and prevents the expansion of the foam or therefore the use of such paints.
    [0074]
    [0075] Unlike the solutions proposed by the prior art, flat beams with improved fire resistance (called Internally Fire Protected - Slim Floor Beam, IFP-SFB in the present patent and used to exemplify the present invention) for steel slabs - Concrete according to the present invention does not need to be subjected to maintenance operations, since the insulating layer is housed in a cavity, preferably a closed cavity, which protects it from external environmental agents, which will prevent said insulating layer from suffering physical aggressions or chemical In addition, it is aesthetically more acceptable than with projections because the protective layer is not visible and only the lower steel plate is visible
    [0076]
    [0077] It is important to note that the solution to the problems of the prior art proposed by the beams according to the present invention, in which the insulating layer has very specific physicochemical properties defined in claim 1 (ie, a density in the range of 150 -600 kg / m3, a conductivity of less than 0.11 W / mK at 600 ° C and a heat specific above 1,000 J / kg.K) and is interposed between the steel sheet and the profile, it was not obvious a priori.
    [0078]
    [0079] In fact, once an initial prototype beam was developed at the theoretical level according to the present invention, it was necessary to determine, among other variables, whether or not it possessed fire resistance characteristics suitable for the intended use. To evaluate the fire resistance of said initial prototype, it was necessary to submit it to three different test models that interacted with each other (as seen above: a fire model, a thermal model and a mechanical model at high temperatures) and without knowing a priori, if said prototype was to respond in a desirable way to each of them separately and in combination with each other. In addition, these tests had to be carried out in specialized facilities, more specifically, in the Institute of Science and Technology of 1 Concrete (ICITECH), of the Polytechnic University of Valencia, (in Valencia, Spain).
    [0080]
    [0081] In fact, during this test process it was determined that said beam according to the present invention possessed fire resistance characteristics suitable for the intended use, and that it simultaneously complied with the technical specifications established by part 1-1 and 1-2 of Eurocode 4 (EN 1994-1-1: 2004, EN 1994-1-2: 2005), mentioned above.
    [0082]
    [0083] The insulating layer of the beams has, more preferably a density in the range of 175 500 kg / m3, a conductivity of less than 0.10 W / mK at 600 ° C and a specific heat of more than 1,000 J / kg.K, even more preferably a density in the range of 190-450 kg / m3, a conductivity less than 0.09 W / mK at 600 ° C and a specific heat greater than 1,050 J / kg.K, The insulating layer of the beams according to a Even more preferable embodiment of the present invention may comprise, for example and without limitation, fibrosilicates, preferably fibrosilicates marketed by the PROMAT company under the trade name ALSIFLEX® and / or fibrosilicates marketed by the company Morgan Advanced Materials under the trade name Superwool® Plus MD paper.
    [0084]
    [0085] The profile of the beams according to a much more preferable embodiment of the present invention is preferably made of structural steel (ie, steel with thermal and mechanical properties according to Eurocode 4, parts 1-1 and 1-2 and included in the standards EN 10025-1: 2004 and EN 10088-1: 2005, the latter in the case of stainless steels.
    [0086]
    [0087] The bottom plate may be, in a very preferable embodiment of the present invention, of structural steel (EN 10025-1: 2004), stainless steel (EN 10088-1: 2005), or high strength steel (EN 10025-1: 2004). These materials are preferred because they give the metal flat beam (IFP-SFB), according to the invention, a further improvement in fire resistance derived from the use of these materials.
    [0088]
    [0089] In the present invention, the profile (ie the profile of the beam to which the steel sheet is attached) can have any shape that allows it to comprise two wings. Preferably, it is an I-shaped (double T), double U (] [or []) or H profile, according to the transverse plane of the beam perpendicular to its longitudinal direction, where both wings are of the same or different widths. Likewise, the profile can have the axis of greater length of the soul in the transverse plane, like an axis of flat symmetry (where the center of the axis of greater length of both wings and the axis of greater length of the soul are aligned in the transverse plane ), or the profile can be asymmetric (where the center of the axis of greater length of at least one wing and the axis of greater length of the soul are not aligned in the transverse plane). More preferably, the longest axis of the profile core in the transverse plane is an axis of flat symmetry, as in the IFP-SFB beams. In an even more preferred embodiment of the invention, the beam profile is an I-shaped (double T), double U (] [or []) or H profile, where both wings are of the same width and the profile has the axis of greater length of the soul in the transverse plane, like an axis of plane symmetry.
    [0090]
    [0091] A second aspect of the present invention relates to a steel-concrete slab that includes at least one flat beam with improved fire resistance for concrete steel slabs, according to the first aspect of the invention.
    [0092]
    [0093] The steel-concrete flat beam slab according to the present invention is preferably provided with prefabricated, reinforced or prestressed concrete slabs or pre-slabs, prestressed alveolar plates, reinforced or prestressed concrete joists, prefabricated or executed on site (in situ), metal joists or collaborating steel plates, in addition to the tie, suspension or longitudinal reinforcement reinforcement (in English, “rebars”) designed to improve the mechanical capacity of the floor.
    [0094] Likewise, the flat slab according to the present invention is more preferably provided with an upper slab of concrete poured on site (in situ) where the negative reinforcement and the distribution reinforcement are housed, to ensure the monolithism of the slab.
    [0095]
    [0096] A third aspect of the invention relates to a method of manufacturing an improved fire resistance metal flat beam (IFP-SFB) for steel-concrete slabs characterized in that it comprises the following consecutive steps:
    [0097]
    [0098] a) provide a steel profile with at least two wings;
    [0099] b) provide, under the lower wing of the profile, an insulating layer formed by at least one non-combustible material, with a density in the range of 150-600 kg / m3, a conductivity of less than 0.11 W / mK at 600 ° C and a specific heat exceeding 1,000 J / kg.K;
    [0100] c) placing, under the insulating layer, a steel sheet of greater width than the width of the wing on which the insulating layer is disposed; Y
    [0101] d) joining the steel sheet to the profile so that a cavity is defined, preferably a closed cavity, within which the insulating layer is arranged.
    [0102]
    [0103] The fact that, in the process of the invention, the insulating layer is placed under a profile wing, in accordance with step b), before the steel sheet joins the profile, in accordance with step d) , allows the insulating layer to be perfectly arranged inside the cavity formed between the profile, more preferably the lower wing of the profile, and the steel sheet.
    [0104]
    [0105] The joining of the sheet steel to the profile is carried out, preferably, by welding and more preferably, by means of a weld comprising a weld bead that encloses the cavity, or alternatively, two longitudinal continuous weld seams, each of said bends being of welding arranged at the edges of the lower wing of the beam placed on the insulating layer, even more preferably, by means of a weld comprising continuous weld seams, one for each edge of the cavity that is generated.
    [0106] In a preferred embodiment of the process according to the present invention, the beam profile, laminated or reinforced, provided in step a) is made of structural steel (with thermal and mechanical properties according to Eurocode 4, parts 1-1 and 1- 2 and included in standards EN 10025-1: 2004 and EN 10088-1: 2005, the latter in the case of stainless steels.
    [0107]
    [0108] In an even more preferred embodiment of the method according to the present invention, the beam profile is an I-shaped (double T), double U (] [or []) or H-shaped profile.
    [0109]
    [0110] In an even more preferred embodiment of the process according to the present invention, the steel plate of step c) is made of structural steel (EN 10025-1: 2004), stainless steel (EN 10088-1: 2005) or high steel resistance (EN 10025-1: 2004).
    [0111]
    [0112] DESCRIPTION OF THE FIGURES
    [0113]
    [0114] Figure 1A is a cross-sectional view of a prior art SFB beam;
    [0115]
    [0116] Figure 1B is a cross-sectional view of an IFB beam of the prior art;
    [0117]
    [0118] Figure 2 is a cross-sectional view (transverse plane) of a beam (IFP-SFB) according to an embodiment of the present invention, where the longitudinal direction of the beam is perpendicular to the transverse plane;
    [0119]
    [0120] Figure 3 is a graph comparing the behavior - in terms of load versus vertical displacement - of the beam of Figure 1A (belonging to the prior art) and the beam (IFP-SFB) of Figure 2 (according to one embodiment of the present invention);
    [0121]
    [0122] Figure 4 is a graphic representation of the thermal model obtained for different elements of the beam of Figure 1A (belonging to the prior art), as well as for different elements of the beam (IFP-SFB) of Figure 2 (according to one embodiment of the present invention); and
    [0123] Figure 5 is a graphic representation comparing the fire resistance of a flat steel-concrete slab beam section, which includes a beam according to Figure 1A (belonging to the prior art), with the fire resistance of a section of forged steel-concrete flat beam, which includes a beam (IFP-SFB) according to Figure 2 (according to an embodiment of the present invention).
    [0124]
    [0125] PREFERRED EMBODIMENTS OF THE INVENTION
    [0126]
    [0127] Next, a specific example of the invention is described by way of example and without limitation, with reference to the attached figures.
    [0128]
    [0129] Figure 1A shows an example of a beam of the SFB type, belonging to the prior art. Said beam has been designated with the numerical reference (100) and comprises a profile (200) of S355 steel.
    [0130]
    [0131] Said profile (200) is composed of an upper wing (300a), attached to a lower wing (300b), through a core (350). The lower wing (300b) is, in turn, connected to a sheet (400) of S355 steel, through weld seams (500) arranged at the transverse ends of said wing (300b).
    [0132]
    [0133] Figure 1B shows an example of a beam of the IFB type, belonging to the prior art. Said beam has been designated with the numerical reference (100 ') and comprises a 1/2 profile (200') of S355 steel.
    [0134]
    [0135] Said profile (200 ') has, in this case T-shape, so it is only provided with a single upper wing (300'), attached to a soul (350 '). The free end of the soul (350 ') is connected, in turn, to a sheet (400') of S355 steel, through two welds (500 ').
    [0136]
    [0137] Figure 2 shows an exemplary non-limiting embodiment of a beam (10) (IFP-SFB), according to the present invention. As can be seen in said Figure 2, the beam (10) comprises an H-shaped steel profile (20) S355, provided with a lower wing (30) that is in contact with an insulating layer (50). The width of the wing (30) has been designated with the reference (W2).
    [0138] Also, in the embodiment shown in Fig. 2 the insulating layer (50) is formed of fibrosilicates, a non-combustible insulating material of type ALSIFLEX®-1260, with a density in the range of 200-400 kg / m3, a conductivity less than 0.08 W / mK at 600 ° C and a specific heat greater than 1,080 J / kg.K.
    [0139]
    [0140] The beam (10) also comprises a sheet (40) of S355 steel, of width W1, which is connected by longitudinal cords (60a) and (60b), of welding, to the lower wing (30). Thus, between the profile (20) and the sheet (40) a cavity is defined in which the insulating layer (50) is arranged inside.
    [0141]
    [0142] Figure 3 is a graph that compares the behavior in terms of load versus vertical displacement of the beam (100) (belonging to the prior art, shown in Figure 1A and which will also be referred to hereafter as "SFB beam ”) And the beam (10) (according to the invention, shown in Figure 2 and which will also be referred to interchangeably as an example of an“ IFP-SFB beam ”).
    [0143]
    [0144] It can be seen that for the SFB beam of the prior art as well as for the IFP-SFB beam according to the present invention, a similar maximum load of about 115 kN was obtained. This implies that the IFP-SFB beam according to the invention has the same behavior at room temperature as a prior art SFB beam.
    [0145]
    [0146] In order to obtain Fig. 4, it was based on a fire model, according to the standard temperature curve (ISO834-1: 1999) of Article 3.2.1 of EN1991-1-2: 2002. Subsequently, tests were carried out to record the evolution over time of the section temperature, by means of thermocouples arranged at different points, both of the SFB beams, and of the IFP-SFB beams.
    [0147]
    [0148] Figure 4 shows, therefore, the evolution as a function of the temperatures obtained for the following elements of the SFB beam (belonging to the prior art and shown with the numerical reference (100) in Figure 1A):
    [0149] • The steel plate (400) (whose graphic representation is the one indicated with the legend "SFB plate"); and
    [0150] • The lower wing (300b) (whose graphic representation is the one indicated with the legend "SFB wing");
    [0151]
    [0152] Said Figure 4 also includes a graphic representation (indicated with the legend "Ref. SFB") of the evolution of temperatures for a longitudinal reinforcement reinforcement that is part of a steel-concrete slab of the slim floor type, including said slab, in addition , an SFB beam embedded in the floor slab.
    [0153]
    [0154] Also shown in Figure 4 is a graphic representation of the thermal response for the following elements of the IFP-SFB beam (according to the present invention and shown with the numerical reference (10) in Figure 2):
    [0155]
    [0156] • The steel sheet (40) (whose graphic representation is indicated by the legend "sheet IFP-SFB"); and
    [0157] • The wing (30) (whose graphic representation is the one indicated with the legend "IFP-SFB wing");
    [0158]
    [0159] Finally, Figure 4 includes a graphic representation (indicated with the legend "Ref. IFP-SFB") of the thermal model obtained for a longitudinal reinforcement reinforcement that is part of a steel-concrete slab of the slim floor type, including said forging, in addition, an IFP-SFB beam embedded in the edge of the floor.
    [0160]
    [0161] It can be seen that, for the IFP-SFB beam (according to the present invention), the temperature difference between the steel sheet (40) and the lower wing (30) of the profile passes, after 120 minutes of exposure to fire, from about 100 ° C to just over 250 ° C. In addition, a greater than 50 ° C reduction in the temperature of the slab reinforcement that includes the IFP-SFB beam is observed, with respect to that of the slab reinforcement that includes the SFB beam.
    [0162]
    [0163] This temperature reduction, both along the steel profile (20), and in the reinforcements, due to the interposition of the insulating layer on the IFP-SFB beam, produces a significant increase in its fire resistance.
    [0164]
    [0165] This statement is demonstrated in Figure 5, which shows the evolution of the mechanical capacity of a steel-concrete floor slab that includes an IFP-SFB beam according to the present invention, and the evolution of the mechanical capacity of a concrete steel slab section that includes a prior art SFB beam.
    [0166]
    [0167] For this, a model of mechanical behavior of materials at high temperatures is used, for increasing exposure to a normalized temperature curve of time (ISO-834-1: 1999, EN1991-1-2: 2002).
    [0168]
    [0169] As can be seen in Fig. 5, the reduction in mechanical capacity for increased exposure to fire in the slab section that includes an IFP-SFB beam, according to the present invention, is less than in the slab section that includes a SFB beam of the prior art. In fact, for a load level of 41% of the cold capacity of the section, the slab section that includes an IFP-SFB beam allows an increase in resistance from R60 to approximately R90 and for a load level of 21 %, the increase is from R120 to more than R180, as summarized in the following table:
    [0170]
    [0171]
    [0172]
    [0173]
    [0174] Being ^ the oversize coefficient of the section under study and Rt the resistance under study at time t.
    [0175]
    [0176] Consequently, it can be concluded that, depending on the degree of use in a fire situation (oversize coefficient), the IFP-SFB beams according to the present invention and shown with the numerical reference (10) in Figure 2 can improve the resistance time to fire between 30 and 60 minutes, with respect to the prior art SFB beams.
    [0177]
    [0178] Although the invention has been described only in relation to the embodiments referred to herein, it should be understood that other possible combinations, variations and improvements would also be included within the scope of protection of the invention, which is defined exclusively by the appended claims.
    [0179] LIST OF NUMERICAL REFERENCES USED IN THE FIGURES
    [0180]
    [0181] • (10) Beam according to the present invention;
    [0182] • (20) Profile;
    [0183] • (30) Lower wing of the profile that is placed on the insulating layer; • (40) Steel sheet;
    [0184] • (50) Insulating layer;
    [0185] • (60a and 60b) Welding beads;
    [0186] • (W1) width of the steel plate;
    [0187] • (W2) width of the lower wing;
    [0188] • (100) SFB beam of the prior art;
    [0189] • (200) Profile (prior art);
    [0190] • (300a) Upper wing (prior art);
    [0191] • (300b) Lower wing (prior art);
    [0192] • (350) Alma (prior art);
    [0193] • (400) Steel sheet (prior art);
    [0194] • (500) Welding beads (prior art);
    [0195] • (100 ') IFB beam of the prior art;
    [0196] • (200 ') Profile (prior art);
    [0197] • (300 ') Wing (prior art);
    [0198] • (350 ') Alma (prior art);
    [0199] • (400 ') Steel sheet (prior art);
    [0200] • (500 ') Welding beads (prior art).
    权利要求:
    Claims (14)
    [1]
    1. Flat beam (10) for steel-concrete slabs comprising:
    - a profile, rolled or reinforced, (20) of steel with at least one wing (30);
    - a steel sheet (40) attached to the lower wing (30) of said profile (20), the width (W1) of the steel sheet (40) being greater than the width (W2) of the lower wing (30) to which it is attached;
    said beam (10) being characterized in that it also comprises:
    - a cavity formed between the lower wing (30) and the steel plate (40); Y
    - an insulating layer (50), arranged inside the cavity and formed by at least one non-combustible insulating material, with a density in the range of 150-600 kg / m3, a conductivity of less than 0.11 W / mK at 600 ° C and a specific heat exceeding 1,000 J / kg.K.
    [2]
    2. Beam (10) according to claim 1, characterized in that the profile (20) is made of structural steel according to EN 10025-1: 2004.
    [3]
    3. Beam (10) according to any of the preceding claims, characterized in that the profile (20) is an I-shaped profile (double T), double U (] [or []) or H.
    [4]
    4. Beam (10) according to any of the preceding claims, characterized in that the sheet (40) is made of structural steel according to EN 10025-1: 2044, stainless steel according to EN 10088-1: 2005 or high strength steel according to EN 10025-1: 2004.
    [5]
    5. Beam (10) according to any of the preceding claims, characterized in that the insulating layer (50) comprises fibrosilicates.
    [6]
    6. Steel-concrete slab, characterized in that it comprises at least one beam (10) according to any one of claims 1 to 5.
    [7]
    7. Steel-concrete slab according to claim 6, characterized in that it is also provided with prefabricated, reinforced or prestressed concrete slabs or pre-slabs, prestressed alveolar slabs, reinforced or prestressed concrete joists, prefabricated or executed on site, metal joists or sheets of collaborating steel, in addition to the tie, suspension or longitudinal reinforcement reinforcements designed to improve the mechanical capacity of the floor.
    [8]
    8. Steel-concrete slab according to any of claims 6 or 7, characterized in that it is provided with an upper slab of concrete poured on site, where the negative reinforcement and the distribution reinforcement are housed, to ensure the monolithism of the slab.
    [9]
    9. Method of manufacturing beams (10) for steel-concrete slabs, according to any of claims 1 to 5, characterized in that it comprises the following consecutive steps:
    a) provide a steel profile (20) with at least two wings (30);
    b) have, under the lower wing (30) of the profile (20), an insulating layer (50) formed by at least one non-combustible insulating material, with a density in the range of 150-600 kg / m3, a lower conductivity at 0.11 W / mK at 600 ° C and a specific heat exceeding 1,000 J / kg.K;
    c) placing, under the insulating layer (50), a steel sheet (40) of greater width (W1) than the width (W2) of the wing (30) on which the insulating layer (50) is arranged; Y
    d) joining the steel plate (40) to the wing (30) so that a cavity is defined in which the insulating layer (50) is arranged inside.
    [10]
    Method according to claim 9, characterized in that the joining of the steel sheet (40) to the wing (30) of step d) is carried out by welding.
    [11]
    Method according to claim 10, characterized in that the joining of the steel sheet (40) to the wing (30) of step d) is carried out by means of a weld comprising two longitudinal welding cords, each of said cords being of welding arranged in a transverse end of the wing (30) placed on the insulating layer (50).
    [12]
    12. Method according to any of claims 9 to 11, characterized in that the profile (20) provided in step a) is made of structural steel.
    [13]
    13. Method according to any of claims 9 to 12, characterized in that the profile (20) provided in step a) is an I-shaped profile (double T), double U (] [or []) or H.
    [14]
    14. Method according to any of claims 9 to 13, characterized in that the steel sheet (40) of stage c) is made of structural steel according to EN 10025-1: 2004, stainless steel according to EN 10088-1: 2005, or high strength steel according to EN 10025-1: 2004.
    类似技术:
    公开号 | 公开日 | 专利标题
    Milke2016|Analytical methods for determining fire resistance of steel members
    Leshchenko et al.2015|Thermal characteristics of the external walling made of cold-formed steel studs and polystyrene concrete
    Nedviga et al.2017|Fire resistance of prefabricated monolithic reinforced concrete slabs of “Marko” technology
    Ariyanayagam et al.2016|Detrimental effects of plasterboard joints on the fire resistance of light gauge steel frame walls
    Annerel et al.2013|Punching shear tests on flat concrete slabs exposed to fire
    Wei et al.2017|Fire resistance of concrete-filled steel plate composite | walls
    CN207376869U|2018-05-18|The high fireproof thermal insulation wall board of flexible connection
    RU153413U1|2015-07-20|HOLLOW BUILDING WITH ASSEMBLY STEEL STRUCTURE
    Knyziak et al.2019|Fire damage of RC slab structure of a shopping center
    Romero et al.2020|Recent developments and fire design provisions for CFST columns and slim-floor beams
    ES2732719A1|2019-11-25|FLAT BEAM WITH IMPROVED FIRE RESISTANCE FOR STEEL-CONCRETE FORGINGS AND ITS MANUFACTURING PROCEDURE |
    Stadler2012|Design of composite slab systems in case of fire using simplified finite element analyses
    CN207160315U|2018-03-30|Fire-type steel wire net rack thermal-insulating board cast-in-situ steel reinforced concrete self-insulation wall structure
    Ada et al.2018|Assessment of damages on a RC building after a big fire
    Kalmykov et al.2017|Study of fire-resistance of reinforced concrete slab of a new type
    Seputro2001|Effect of Support Conditions on Steel Beams Exposed of Fire
    Vassart et al.2011|Fire resistance of long span cellular beam made of rolled profiles
    Ashton et al.1960|THE FIRE-RESISTANCE OF PRESTRESSED CONCRETE BEAMS.
    Choe et al.2021|Behavior of Composite Floor Assemblies Subject to Fire: Influence of Slab Reinforcement
    Shefer et al.2015|Conception of low-rise earthquake-resistant energy-efficient buildings
    Kisin et al.2015|Corrective measures for noncontact splices in concrete block masonry
    Bellová2016|Fire Walls Made from Concrete and Masonry-Barriers against a Fire Spreading
    Mikaelsson2019|Design optimization in building projects by using composite steel/concrete columns
    CN207376948U|2018-05-18|The high fireproof thermal insulation wall board of rigidity or varied rigid link
    Yu et al.2009|Study on heat insulation properties and mechanical behaviors of multi-ribbed composite wall structure
    同族专利:
    公开号 | 公开日
    ES2732719B2|2021-03-02|
    ES2681568A1|2018-09-13|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    EP0292449A2|1987-05-11|1988-11-23|Jörgen Thor|Fire resistant steel beam coacting with concrete|
    WO1990012173A1|1989-04-13|1990-10-18|Deltatek Oy|A fire-resistant prefabricated steel beam|
    WO2008119876A1|2007-03-30|2008-10-09|Rautaruukki Oyj|Composite beam|
    法律状态:
    2019-11-25| BA2A| Patent application published|Ref document number: 2732719 Country of ref document: ES Kind code of ref document: A1 Effective date: 20191125 |
    2021-03-02| FG2A| Definitive protection|Ref document number: 2732719 Country of ref document: ES Kind code of ref document: B2 Effective date: 20210302 |
    优先权:
    申请号 | 申请日 | 专利标题
    ES201830494A|ES2681568A1|2018-05-23|2018-05-23|FLAT BEAM WITH IMPROVED FIRE RESISTANCE FOR STEEL-CONCRETE FORGINGS AND ITS MANUFACTURING PROCEDURE |
    [返回顶部]