Field of the invention
[0001] The present invention relates to the field of constructions and more precisely it
refers to a structural element such as a ceiling beam in pre-stressed concrete, a
"girder" or the like for making floors, suitable for application of plaster suspended
ceilings. Among floors to which the invention is related to are comprised flat floors
both walkable and not, peaked roofs, floors of roof gardens, shed roofs.
Background of the invention
[0002] For the installation of plaster covered boards for suspended ceilings several known
problems arise.
[0003] In fact, the plaster suspended ceilings require metallic frameworks to which plaster
covered boards are connected by means of self tapping screws. The frameworks are in
turn screwed to the floors by means of screw anchors. In particular, it is difficult
the drilling of concrete beams or other structural elements, usually in reinforced
concrete. Furthermore it is in any case difficult to arrange metallic frameworks for
supporting plaster suspended ceilings.
[0004] An important aspect of the construction of floors is the so called "vapour barrier",
i.e. an insulation from humidity and vapour in gaseous phase that can give condensate
water. In theory, the vapour barrier should be made at the lowermost surface of the
floor. However, with traditional techniques of construction of floors the vapour barrier
is made over the upper level of the floor, leaving not protected all the layer of
the floor. This fact involves high costs in creating the insulating pack of the floor.
[0005] The vapour barrier normally is a sheet of aluminium integrated to a waterproof membrane.
A typical floor, then, starting from the above towards below has a concrete casting
with pavement, a waterproof membrane, an heat insulation, the vapour barrier by means
of membrane with a sheet of aluminium, a primer, a reinforced concrete and hollow
tiles mixed floor, and, at the lowermost surface, a plaster coating.
[0006] Therefore, it would be advantageous to move the vapour barrier towards below, eliminating
the membrane with the sheet of aluminium and using plaster covered boards with integrated
a sheet of aluminium or other equivalent vapour barrier. It is, however, complicated
as above described to install plaster suspended ceilings in a way that is quick and
not expensive on the floors lower surfaces.
Summary of the invention
[0007] It is therefore object of the present invention to provide a structural element such
as a ceiling beam or girder or pre-stressed concrete beam and similar, for making
floors, roofs, etc., which makes remarkably easier the application of plaster suspended
ceilings, without reducing the resistance of the final structure.
[0008] It is another object of the invention to provide a method for the production of this
structural element.
[0009] Hereinafter, with the term structural element a desired ceiling beam, girder or the
like for floors is intended to define an element that achieves the principles according
to the invention as described and claimed below.
[0010] According to a first aspect of the invention, a structural element has a concrete
casting with a lower flat face in which a layer is integrated that can be perforated
by screws capable of making easier the installation and of supporting the weight of
plaster suspended ceilings.
[0011] The layer that can be perforated by screws can be advantageously formed by a sheet
section in which a layer is present of light material that is set between the concrete
and the sheet section, directly contacting the concrete casting.
[0012] The light material can be chosen among foam polystyrene, cellular polyurethane, wood,
etc.
[0013] The layer that can be perforated by screws can be integrated to the concrete at casting
the concrete. Alternatively, the layer that can be perforated can be connected to
the casting by means of screws or riveting after the casting, through brackets embedded
in the casting same. The light material can, in this second case, be integrated at
the moment of the casting or at the moment of the fastening of the sheet section to
the casting.
[0014] The sheet section, filled with the layer of light material, at the moment of installing
the structural element is oriented towards below integrated in the floor or roof and
allows thus the easy application of the screws, which cross both the plaster suspended
ceilings and the sheet section and can penetrate all the layer of light material without
forcing against the concrete. This way, a plaster suspended ceiling can be made directly
connected to the lower face of the floor.
[0015] The concrete casting can be made with free or pre-stressed reinforcement bars, in
order to obtain in the first case a girder for building industry and in the second
case a concrete pre-stressed beam.
[0016] According to another aspect of the present invention, a method for the production
of a structural element for making floors has the characteristic that it comprises
the following steps:
- prearranging a concrete mould or equivalent material for casting the structural element;
- arranging in said mould a reinforcement of the structural element, for example of
iron bars;
- arranging always in said mould, a fastening for a sheet section having a flat face
oriented towards below, in said sheet section being pre-arranged a layer of light
material.
In a first embodiment of the method, the steps are provided of
- introducing in the mould said sheet section having a flat face oriented towards below
that lays on the bottom of the mould, in said sheet section a layer of light material
being pre-arranged;
- casting concrete in said mould incorporating said sheet section, said layer and at
least part of said reinforcement;
- extracting the structural element after hardening comprising a lower face of sheet
section and the layer in light material integrated to the concrete and to the relative
reinforcement that is embedded between the concrete and the sheet section.
In a second embodiment of the method, the steps are provided of
- introducing in the mould brackets oriented towards below and capable of protruding
from the concrete after the casting;
- casting concrete in said mould incorporating part of said reinforcement and of said
brackets;
- after hardening, fastening by means of screws or rivets said sheet section to said
brackets, said sheet section having a flat face oriented towards below.
[0017] The light material can, in this second case, be preferably integrated at the moment
of the casting, arranged between the brackets. Alternatively, it can be connected
at the moment of fastening the sheet section to the casting.
[0018] The length of the sheet section can in a first case extend for all the length of
the structural element. In this case, the sheet section has the lower flat face that
covers all the bottom face of the concrete casting, whereby the lower face of the
structural element is completely a sheet section.
[0019] In a second embodiment a plurality of portions of said sheet section arranged is
provided aligned longitudinally, spaced and centred transversally. The width of the
portions can be also less than the width of the casting, whereby the lower face of
the structural element is made of concrete with at the centre a row of spaced portions
of sheet section. It is also possible that the sheet section is continuous instead
of discontinuous and of width less than the girder.
[0020] Advantageously, the sheet section is U-shaped. In it the light material lays, in
such a way that the wings of the sheet section protrude from the layer of said light
material. In the first embodiment, the protruding wings allow to the whole support,
consisting in the sheet section and in the polystyrene foam layer, of being connected
by means of screws directly to the wall side of the beam. In the second embodiment,
the protruding wings offer a steadier fastening to the concrete.
[0021] According to the invention, the plaster suspended ceilings are screwed to the sheet
section. In fact, the screws penetrate directly through the plaster board and through
the surface of the sheet section into the light material in it contained.
[0022] In particular, floors made with concrete beams according to the invention, allow
a quick installation of the plaster suspended ceilings. In fact, the plaster covered
boards are directly connected to the beams of the floor in a steady way and adhere
directly to the floor lower surface. With such an installation the working costs mainly
given to the installation of a metal framework are eliminated.
[0023] If the plaster suspended ceilings are to be replace or removed, it is sufficient
to release the plaster covered boards from the floor lower surface, without affecting
further the ceiling beam.
[0024] A further advantage is that of providing a vapour barrier near the lower level of
the floor. In this case, plaster suspended ceilings may be used equipped with a sheet
in aluminium.
[0025] Furthermore being the girder according to the invention pierceable by the screws,
it is possible to bolt it directly to the principal steel structures of the building,
such as for example to the steel beams, or it can be connected by epoxy resins.
[0026] Advantageously, the lower parts of the sheet section can be coated of a insulating
layer, for example, but not exclusively, adhesive layer of cellular polyethylene with
a layer of some mm.
Brief description of the drawings
[0027] Further characteristics and the advantages of the structural element according to
the present invention will be made clearer with the following description of an embodiment
thereof, exemplifying but not limitative, with reference to the attached drawings,
wherein:
- figure 1 shows a sectional view of a portion of floor in direct phase of installation
with two structural elements according to the invention;
- figure 2 shows a perspective view of the floor of figure 1 after the application of
an plaster covered board;
- figure 3 shows a perspective view of a mould of casting of a structural element according
to the invention with pre-arranged a sheet section and a layer of light material;
- figure 4 shows a sectional view of the mould of figure 3 after the casting;
- figure 5 shows an elevational longitudinal view of the structural element according
to the invention as resulting after the casting;
- figure 6 shows a perspective view of a mould of casting of a structural element according
to the invention with pre-arranged a plurality of sheet section discontinued portions
and inside layers of light material ;
- figure 7 shows a sectional view of the mould of figure 6 after the casting;
- figure 8 shows a plan view from below of a different embodiment of the structural
element according to the invention as resulting after the casting according to figures
6 and 7;
- figures 9a and 9b show an elevational view, respectively frontal and longitudinal,
of a reinforcement equipped with brackets concerning a different embodiment of the
invention;
- figures 10a and 10b show an elevational view, respectively frontal and longitudinal,
of the reinforcement of figures 9a and 9b after the application of a layer of light
material ;
- figures 11a 11b show an elevational view, respectively frontal and longitudinal, of
the reinforcement of figure 10a and 10b after casting of the concrete;
- figures 12a and 12b show an elevational view, respectively frontal and longitudinal,
of the ceiling beam of figure 11a 11b to whose base a sheet section has been attached;
- figures 13a and 13b show an elevational view, respectively frontal and longitudinal,
of a ceiling beam of pre-stressed concrete to whose base a sheet section has been
mounted;
- figures 14 and 15 show respectively a structural element according to the invention
in reinforced concrete and in pre-stressed concrete after the fastening to a steel
structural beam.
Description of a preferred embodiment
[0028] With reference to figures 1 and 2, a structural element 1 according to the invention
is used for making a floor 2 of known type in combination with hollow tiles 3. In
particular, is shown a hollow tile 3 resting on two structural elements 1. In the
building industry, the structural element of figure 1 is normally defined as "girder",
whereas the structural element of figure 2 is normally defined as "ceiling beam" in
pre-stressed concrete.
[0029] According to the invention, each structural element 1 consists in a reinforcement
4 and by a sheet section 5, embedded in a concrete casting 6. The sheet section 5
is filled with a layer of light material 8 that is set between the concrete 6 and
the sheet section 5 and is oriented in use towards below of the floor for application
of plaster suspended ceilings 9 (figure 2).
[0030] In fact, since the sheet section 5 can be easily perforated, for example with self
tapping screws 10, and since the light material 8 allows free penetration, the plaster
suspended ceilings 9 are easily screwed to the structural elements 1. More precisely,
the screws 10 cross in turn the plaster board 9, the lower face of the sheet section
5 and penetrate all the layer of the light material 8 without forcing , unless at
the end of the movement, against concrete 6. This way a floor lower surface made of
plaster board is created directly connected to the concrete beams of floor 2.
[0031] With reference to figures 3 and 4, to make the girder 1 according to the invention,
which can be seen in longitudinal vista also in figure 5, it is sufficient to provide
a mould 7 for casting concrete. In a first step the sheet section 5 with a face 5a
oriented towards below is laid onto the base 7a of mould 7. Over base 7a of mould
7, the reinforcement 4 is arranged that, after the casting of concrete 6, becomes
the reinforcement of the structural element 1.
[0032] In the embodiment of figures from 1 to 5, the length of the sheet section 5 extends
for all the length of the structural element 2.
[0033] Advantageously, the side walls 11 of the sheet section 5 are slightly higher of the
layer of the light material 8 in it contained, creating thus two protruding wings
11a. Such protruding wings 11a allow to the sheet section 5 and to the light material
8 to be connected by means of screws 12 directly to the wall side of the floor beam
2 (figure 2 and 5) by means of pins not shown, previously inserted in the mould.
[0034] With reference to figures from 6 to 8, in a second embodiment of the invention, the
structural element 1' comprises a plurality of portions 5' of sheet section arranged
aligned longitudinally, spaced and centred transversally for a width less than that
of the structural element 1'. The portions of sheet section 5' are inserted in the
mould 7 alternated before casting the concrete (figure 6 and 7). This way, a structural
element is obtained that has a lower face in concrete 6 (figure 8), discontinued by
the portions of sheet section 5', which can be used for fastening plaster covered
boards.
[0035] Figures from 9A to 11B show in turn the steps of a further embodiment of the invention.
With reference to figures 9A and 9B, respectively in front and longitudinal view,
a reinforcement 4 is arranged, of traditional type, to which brackets 13 are welded.
Blades 14 are also provided that define the position of the sheet of light material
8 (Figure 10A and 10B). In particular, the brackets 13 are welded to reinforcement
4 spaced as shown in figure 9B.
[0036] As shown in figures 11A and 11B it is sufficient to put the reinforcement thus equipped
in a mould for casting the concrete 6. To make the base in sheet section on the girder
1, as shown in figure 12A and 12B, it is sufficient to fasten by means of screws 12
the sheet section 5, which is put on the floor beam, causing the self tapping screws
12 to penetrate brackets 13 and then blades 14.
[0037] Lo same method can be can be used for making a floor beam of pre-stressed concrete
1'', shown in figures 13A and 13B.
[0038] Structural elements 1, 1' or 1'', thus made, can be easily connected to a structural
H beam 16 of steel, as shown in figures 14 and 15. In fact, it is sufficient to use
screws 15 that penetrate the sheet section 5.
[0039] Structural elements 1 thus made allow a quick fastening of the ceiling of plaster
covered boards 9 directly to the lower surface of the floor. This way, it is not necessary
to install additional frameworks to the plaster suspended ceilings 9.
[0040] The possibility of coating the lower surface of the floor with plaster covered boards
9 connected with screws 10 (figure 2) is particularly advantageous , since the traditional
concrete beams of reinforced concrete cannot be pierced by the screws. The advantages
are not only in quicker installation, but also in a less operative work, with a subsequent
reduction of the costs of construction. A further advantage, furthermore is the possibility
of using plaster covered boards 9 with embedded sheet of aluminium to provide the
vapour barrier at the lowermost level of the floor.
[0041] In a way not shown, finally, the lower face of the sheet section 5 may be coated
with an insulating layer, in species cellular polyethylene some mm thick. This way,
the heat bridge that usually affect floors near the beams is eliminated, caused by
the higher heat conductivity of the concrete beams with respect to the rest of the
floor, which comprises hollow tiles.
[0042] The foregoing description of a specific embodiment will so fully reveal the invention
according to the conceptual point of view, so that others, by applying current knowledge,
will be able to modify and/or adapt for various applications such an embodiment without
further research and without parting from the invention, and it is therefore to be
understood that such adaptations and modifications will have to be considered as equivalent
to the specific embodiment. The means and the materials to realise the different functions
described herein could have a different nature without, for this reason, departing
from the field of the invention. It is to be understood that the phraseology or terminology
employed herein is for the purpose of description and not of limitation.
1. A structural element such as a floor reinforced girder or pre-stressed concrete beam
and similar, for making floors, roofs, etc., characterised in that it comprises a casting (6) in concrete with a lower flat face to which a layer is
integrated (5,8) that can be perforated by screws (10) capable of making easier the
fastening and of supporting the weight of plaster suspended ceilings (9).
2. Structural element according to claim 1, wherein said layer that can be perforated
by screws is formed by a sheet section (5) in which a layer is present of light material
(8) that is set between the concrete and the sheet section, directly contacting the
concrete casting.
3. Structural element according to claim 2, wherein said layer of light material (8)
is chosen among foam polystyrene, cellular polyurethane, wood.
4. Structural element according to claim 2, wherein the lower part of said sheet section
(5) is coated of a insulating layer, in species cellular polyethylene some mm thick.
5. Structural element according to claim 2, wherein said sheet section (5) a U shaped
cross section, in it said light material (8) being laid, in such a way that the wings
(11) of the sheet section protrude with respect to the layer of said light material
(8), said wings (11) being connected to said casting (6) by means for fastening it
to the concrete.
6. Method for the production of a structural element for making floors having the characteristic
that it comprises the steps of:
- prearranging a mould (7) for casting the structural element;
- arranging in said mould a reinforcement (4) of the structural element, for example
of iron bars,;
- arranging, always in said mould, a sheet section (5) having a flat face oriented
towards below, in said sheet section a layer of light material being pre-arranged(8).
7. Method according to claim 6, wherein the further steps are provided of:
- introducing in the mould said sheet section (5) having a flat face oriented towards
below that lays on the bottom of the mould (7), in said sheet section a layer of light
material being pre-arranged(8);
- casting concrete in said mould incorporating said sheet section, said layer (8)
and at least part of said reinforcement (4);
- extracting the structural element (1) after hardening comprising a lower face in
sheet section (5) and the layer in light material (8) integrated to the concrete (6)
and to the relative reinforcement (4) that is set between the concrete and the sheet
section (5).
8. Method according to claim 6, wherein the further steps are provided of:
- introducing in the mould (7) a reinforcement (4) having a plurality of brackets
(13) oriented towards below and capable of protruding from the concrete (6) after
casting;
- putting on the bottom of said mould (7) and between said brackets (13) a layer of
light material (8);
- casting concrete (6) into said mould (7) incorporating part of said reinforcement
(4) and of said brackets (13) and, beneath, said layer of light material (8);
- once the casting (6) is hardened, fastening by means of screws (12) or rivets said
sheet section (5) to said brackets (13), said sheet section (5) having a flat face
oriented towards below and enclosing said layer of light material (8).
9. Method according to claim 6, wherein the length of the sheet section (5) extends for
all the length of the structural element, said sheet section (5) having a lower flat
face that covers all the bottom of the mould (7), whereby the lower face of the structural
element is completely of sheet section (5).
10. Method according to claim 6, wherein a plurality of portions (5') is provided of said
sheet section arranged aligned longitudinally, spaced and centred transversally, the
width of said portions being less than the width of said mould (7), whereby the lower
face of the structural element (1') is of concrete alternared to a row of spaced portions
of sheet section (5).