[0001] The present invention relates to a prefabricated sound insulating and sound absorbing
panel for building construction, roads, tunnels and the like. The invention further
relates to the process for manufacturing such panel.
[0002] The need of reducing annoying and/or harmful noises is felt not only in the field
of civil and industrial building construction but also in that of roads and road and
railway tunnels.
[0003] Document
CN101634176A describes a light panel for building constructions comprising an outer layer and
an inner core and wherein blast furnace slag is used as component of the outer layer,
whereas the inner core is of polystyrene foam. The outer layer of such known panel
exhibits sound insulation features. However, the above known panel has quite limited
sound insulation features as it exhibits a structure not suitable for carrying out
the dual and necessary function of sound insulating barrier and sound absorbing barrier
for the effective noise reduction. Moreover, in the above known panel, while the slag
is used as sound insulation means, the same is not structurally distributed in an
optimal manner, also considering the shape thereof and the grain size thereof, for
carrying out, as said, the dual function of sound insulating barrier and sound absorbing
barrier.
[0004] Starting from the notion of the above drawbacks, the present invention aims to solve
them.
[0005] An object of the present invention is to provide a prefabricated panel which concurrently
provides a sound insulating barrier and a sound absorbing barrier for the effective
reduction of annoying and/or harmful noises in building construction, roads, tunnels
and the like.
[0006] Another object of the present invention is to provide a prefabricated sound insulating
and sound absorbing panel for building construction, roads, tunnels and the like which
is easy to manufacture, has a certain effectiveness and is easy to install.
[0007] Yet another object of the present invention is to provide a process for manufacturing
a prefabricated sound insulating and sound absorbing panel for building construction,
roads, tunnels and the like which is quick and easy to manufacture.
[0008] In view of such objects, the present invention provides a prefabricated sound insulating
and sound absorbing panel for building construction, roads, tunnels and the like the
fundamental feature whereof is the object of claim 1.
[0009] The essential feature of the process for manufacturing the prefabricated sound insulating
and sound absorbing panel for building construction, roads, tunnels and the like,
according to the present invention, is the object of claim 7.
[0010] Further advantageous features are listed in the dependent claims. All the claims
are intended as integrally reported herein.
[0011] The present invention will appear more clearly from the following detailed description
made with reference to the annexed drawing provided by way of a non-limiting example
only, wherein:
- fig. 1 shows a perspective view of an exemplary embodiment of a prefabricated sound
insulating and sound absorbing panel for building construction, roads, tunnels and
the like, object of the invention;
- fig. 2 shows a perspective enlarged scale view of a tile component of the prefabricated
panel according to fig. 1. General features of the slag in prefabricated construction panels
[0012] In general, slag is widely used as inert material for prefabricated construction
panels also with sound insulation purposes. In such use, it is mixed with other components
in a known manner for forming a layer of the panel (
CN101634176A). The known literature does not specifically indicate the shape or grain size of
the slag used to this end.
[0013] Blast furnace slag (or blast furnace dross) is a by-product of the cast iron manufacturing
process during which large amounts of liquid dross are formed having a composition
similar to Portland concrete. The dross acquires hydraulic features if, at the exit
from the blast furnace, it is suddenly cooled and transformed into porous granules
with a vitreous structure (amorphous silica), a material called granular slag. Subsequently,
this material is ground so as to obtain a powder having fineness comparable to that
of concrete.
[0014] It is important to note that, according to the grain size, the slag has both sound
insulating (when in powder state) and sound absorbing properties (when in natural
granular state).
[0015] From a construction viewpoint, basic granulated slag is used for making prefabricated
panels, which by itself has hydraulic properties, i.e. the capability of hardening
in contact with water. However, since such hardening is per se very slow, in order
to accelerate it, basic granulated slag is associated with other binders, which act
as hydraulic property activators. Moreover, the slag concrete is particularly suitable
for making workpieces that require a high resistance to the disintegrating action
of atmospheric agents, as well as in massive casting, due to its feature of having
a low hydration heat. Moreover, slag proportionally increases the resistance to chemical
attacks: it is particularly indicated for those workpieces that may come into contact
with aggressive waters.
[0016] It should be noted that slag is treated as non hazardous industrial waste.
[0017] Therefore, the use of slag in prefabricated panels improves permeability and resistance
to the attack of environmental chemical agents, imparting better duration features
to the end product as compared to other blends.
Exemplary embodiment of the panel according to the invention
[0018] In fig. 1, reference numeral 10 globally indicates an exemplary embodiment of the
prefabricated sound insulating and sound absorbing panel for building construction,
roads, tunnels and the like, object of the invention.
[0019] Said panel 10 comprises a plurality of prefabricated tiles 11 (fig. 2), assembled
and steadily fixed to each other, in a geometrical arrangement according to lines
and columns, so as to form a prefabricated wall element or the like 12, comprising
a back base layer 12.1 substantially shaped as a parallelepiped sheet and a front
facing layer 12.2 with a rusticated surface, having a plurality of pyramid cusps 13
with alternating orientation.
[0020] Two sturdy U-shaped metal section bars 14, parallel to each another, are respectively
steadily fixed on opposite sides of panel 10 and are open outwards: they constitute
support and connection elements for making a workpiece with prefabricated modular
components.
[0021] Each prefabricated tile 11 (fig. 2) comprises, correspondingly and in a single body,
two adhering structural layers, i.e.:
- a parallelepiped back base layer 11.1, made with a deep blending of concrete and slag
in powder state and forming a barrier with a high sound insulating power, and
- a cusp front facing layer 11.2, made with a deep blending of concrete and slag in
natural granulated state, so-called granular slag, and forming a barrier with a high
sound absorbing power.
[0022] A metal armour 15, for example grid-like, is interposed between said back layer 11.1
and said front facing layer 11.2 of tile 11 for connecting said parts and structurally
reinforcing the same tile.
[0023] An example of blends for making each of said two layers 11.1, 11.2 of said tile 11
and thus of panel 10 is provided hereinafter.
[0024] Sound insulating blends for making the back layer 11.1 constituting a sound insulating
barrier (percentages by weight):
Foamed clay 5-40%, slag 5-60%, sand 5-40%, concrete 10-30%, added water 5-10%, additive
CTC < 2%, gravel 5-50%. The slag is provided as ground powder.
[0025] Blends for making the front facing layer 11.2 constituting a sound absorbing barrier
(percentages by weight):
Foamed clay 5-40%, slag 5-60%, sand 5-40%, concrete 10-30%, added water 5-10%, additive
CTC < 2%. The slag is provided in natural grain shape, i.e. as so-called granular
slag.
[0026] Indicative and exemplary dimensions of a prefabricated sound insulating and sound
absorbing panel for building construction, roads, tunnels and the like, according
to the invention.
[0027] The dimensions shall differ according to the different uses and to the features of
the positioning place:
- minimum dimensions: length 50 cm , width 25 cm, thickness 15 cm;
- maximum dimensions: length 500 cm, width 150 cm, thickness 50 cm.
[0028] As is clear from the above, the panel according to the invention may also be made
as a single body (rather than with a plurality of assembled tiles), comprising a back
base layer constituting the sound insulating barrier and a front facing layer constituting
the sound absorbing barrier.
[0029] The process for manufacturing the prefabricated sound insulating and sound absorbing panel for building construction,
roads, tunnels and the like, according to the invention, comprises the following steps:
- in a suitably shaped formwork or mould, a first partial casting is made of a deep
blending of concrete and slag in natural granulated state (granular slag), so as to
form a front facing constituting a barrier with a high sound absorbing power;
- a second partial casting is then made for filling said formwork or mould, of a deep
blending of concrete and powder slag, so as to form a back layer constituting a barrier
with a high sound insulating power;
- the natural drying and hardening of the workpiece (8 to 12 hours, according to the
operating conditions), or the drying and forced hardening in furnace (3 to 5 hours)
are then carried out;
- and, finally, the operations for detaching the workpiece from said formwork or mould
are carried out.
[0030] Advantageously, in said formwork or mould, a suitable metal armour, for example a
grid, is positioned on said first casting for reinforcement and connection with said
second casting.
[0031] As it appears from the above description, the present invention allows the objects
described in the introduction of the present description to be achieved in a simple
and advantageous manner.
1. Prefabricated sound insulating and sound absorbing panel (10) for building construction,
roads, tunnels and the like, comprising at least two structural layers (11.1, 12.1;
11.2, 12.2), one of which at least contains blast furnace slag as sound insulating
material,
characterized in that said panel (10) comprises:
- a back base layer (11.1; 12.1), made with a deep blending of concrete and slag in
powder state and forming a barrier with a high sound insulating power, and
- a front facing layer (11.2; 12.2), made with a deep blending of concrete and slag
in natural granulated state, so-called granular slag, and forming a barrier with a
high sound absorbing power.
2. Panel according to claim 1,
characterized in that said panel (10) comprises a plurality of prefabricated tiles (11), assembled and
steadily fixed to one another so as to form a prefabricated wall element or the like
(12), and
in that each prefabricated tile (11) comprises two adhering structural layers:
- a back base layer (11.1), made with a deep blending of concrete and slag in powder
state and forming a barrier with a high sound insulating power, and
- a front facing layer (11.2), made with a deep blending of concrete and slag in natural
granulated state, so-called granular slag, and forming a barrier with a high sound
absorbing power.
3. Panel according to claim 1 and/or 2, characterized in that said panel, respectively each prefabricated tile (11) of said panel, comprises a
metal armour (15) for connecting said layers and for structural reinforcement.
4. Panel according to any one or more of the previous claims, characterized in that said front facing layer (11.2, 12.2) exhibits a rusticated surface (13).
5. Panel according to one or more of the previous claims,
characterized in that said back layer (11.1, 12.1) is made with a deep blending of concrete and slag in
powder state containing the following components (percentages by weight):
- foamed clay 5-40%, slag 5-60%, sand 5-40%, concrete 10-30%, added water 5-10%, additive
CTC < 2%, gravel 5-50%, and
said front layer (11.2, 12.2) is made with a deep blending of concrete and slag in
natural granulated state, so-called granular slag, containing the following components
(percentages by weight):
- foamed clay 5-40%, slag 5-60%, sand 5-40%, concrete 10-30%, added water 5-10%, additive
CTC < 2%.
6. Panel according to claim 1, characterized in that it comprises two sturdy substantially U-shaped metal section bars (14), parallel
to one another, respectively steadily fixed on opposite sides of the same panel (10)
and open outwards, which constitute support and connection elements for making a workpiece
with prefabricated modular components.
7. Process for making the prefabricated sound insulating and sound absorbing panel for
building construction, roads, tunnels and the like, according to one or more of the
previous claims,
characterized in that it comprises the following steps:
- in a suitably shaped formwork or mould, a first partial casting is made of a deep
blending of concrete and slag in natural granulated state, so-called granular slag,
so as to form a front facing constituting a barrier with a high sound absorbing power.
- a second partial casting is then made for filling said formwork or mould, of a deep
blending of concrete and powder slag, so as to form a back layer constituting a barrier
with a high sound insulating power;
- the natural drying is carried out with hardening of the workpiece (8 to 12 hours,
according to the operating conditions), respectively the drying with forced hardening
in furnace (3 to 5 hours);
- the operations for detaching the workpiece from said formwork or mould follow.
8. Process according to claim 7, characterized in that in said formwork or mould, a suitable metal armour is positioned on said first casting
for reinforcement and connection with said second casting.