(19) |
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(11) |
EP 1 790 792 A2 |
(12) |
EUROPEAN PATENT APPLICATION |
(43) |
Date of publication: |
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30.05.2007 Bulletin 2007/22 |
(22) |
Date of filing: 24.11.2006 |
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(51) |
International Patent Classification (IPC):
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(84) |
Designated Contracting States: |
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AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU LV MC NL PL PT RO SE
SI SK TR |
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Designated Extension States: |
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AL BA HR MK YU |
(30) |
Priority: |
28.11.2005 IT BO20050074 U
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(71) |
Applicant: Fili & Forme S.r.l. |
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41018 San Cesario sul Panaro (IT) |
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(72) |
Inventors: |
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- Fabri, Paola
40069 Zola Predosa (IT)
- Gamberini, Lorena
40010 Calcara (IT)
- Nobili, Andra
41100 Modena (IT)
- Salvadore, Mariano
40017 San Giovanni Persiceto (IT)
- Tarantino, Angelo Marcello
60019 Senigallia (IT)
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(74) |
Representative: Jorio, Paolo et al |
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Studio Torta S.r.l.
Via Viotti, 9 10121 Torino 10121 Torino (IT) |
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(57) The building artefact comprises a mixture (2) of inert material and of bonding material
and a plurality of plastic material fibres (3) embedded in the mixture (2). The main
feature of such artefact (1) consists in the fact that the fibres (3) present at least
two subsequent sections (5 and 6) which converge in a convergence point (4).
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[0001] The present invention relates to a building artefact.
[0002] As it is known, building artefacts are formed by a mixture of inert materials and
bonding material, such as for example concrete. It is also known that in order to
increase tensile strength, a structure defined by bars or rods formally formed by
iron or an iron-based alloy is positioned within the aforesaid mixture. If on one
hand an increase of the tensile strength is obtained by reinforcing the artefact with
an iron structure, on the other hand some problems or drawbacks are introduced. A
first drawback is due to the considerable costs of iron procurement and of complex
structure assembly, by specialised personnel. A second drawback is due to the fact
that concrete is a porous material and therefore water, salinity or other atmospheric
elements which attack the artefact may extend within the latter and attack the iron
structure with all the disadvantages which derive therefrom on the mechanical strength
of the artefact itself. Furthermore, the iron structure is inserted within the artefact
in well-defined positions and this determines a lack of homogeneity of the mechanical
features of the artefact between the zones in which the reinforcement is present and
the zones from which the reinforcement is absent, the latter zones being subject to
crumbling. In order to avoid the aggression of the iron structure and the crumbling
it is used to fill the pores of the artefact with resins which however in turn introduce
other drawbacks, such as manufacturing costs and the toxicity of such resins. In order
to overcome the aforementioned drawbacks, some companies have adopted, sometimes in
combination with the metallic reinforcement, the introduction in the aforesaid mixture
of plastic material fibres. Such fibres present either a straight longitudinal conformation
or a slightly undulated longitudinal conformation. The main drawback of the aforesaid
fibres consists in the poor grip which occurs between the fibres and the artefact
mixture. As a consequence, the fibres cannot perform their supporting action towards
the concrete matrix, because they tend to slip off the latter before being able to
perform an appreciable mechanical action.
[0003] It is the object of the present invention to make a building artefact which is free
from the aforementioned drawbacks.
[0004] According to the present invention, a building artefact is made of the type comprising
a mixture of inert material and of bonding material and a plurality of plastic material
fibres embedded in said mixture, characterised in that said fibres present at least
two subsequent segments which converge in a convergence point.
[0005] The present invention will now be described with reference to the accompanying drawing
which shows a partial section of a building artefact indicated as a whole by numeral
1.
[0006] Artefact 1 consists of a mixture 2 of inert materials and of bonding material, such
as for example concrete. Within mixture 2, during its preparation step, a plurality
of fibres 3 formed by plastic material is introduced. Fibres 3 preferably present
an elliptical section and a rough surface. Fibres 3 are constituted by a sequence
of straight segments in which each single segment converges with the previous and
next segment in a corresponding convergence point 4 forming a sharp edge to the greatest
possible extent. Specifically, fibre 3 presents a plurality of segments 5 alternated
with segments 6. Segments 5 present a longer length than that of next and previous
segment 6 and define with these an acute angle. Furthermore, all segments 5 are reciprocally
parallel, and all segments 6 are reciprocally parallel.
[0007] In use, according to the mechanical features one intends to confer to artefact 1,
the number of fibres 3 to be embedded in mixture 2 during the preparation of the latter
and the length and the diameter of such fibres 3 is calculated. Subsequently, mixture
2 is cast in a mould (not shown) and after curing such mixture defines artefact 1
ready for use.
[0008] From the description above, the advantages obtained by implementing the present invention
are apparent and numerous.
[0009] Specifically, a building artefact is made within which a plurality of fibres formed
by plastic material is present whose design is appropriately made for the purpose
of significantly increasing the grip with the concrete matrix and consequently obtaining
the maximum mechanical benefit from the property of the fibres. The action of the
latter determines a significant reduction of cracking, an increase of ductility and
tensile strength. Most of these benefits are ascribed to the convergence angles between
the fibre segments, which determine the meshing of the mixture with the fibres. Indeed,
the filling of the subintended zones by the matrix occurs at such convergence points
between adjacent segments. Similarly, the action of a sharp edge is known to induce
a concentration of the stresses in the matrix, which favours the penetration of the
fibre therein and inhibits slipping off. Furthermore, the particular shape of the
fibre and the roughness defined on its surface leads as a consequence to a significant
increase of grip between fibre and mixture. All these features have been assessed
in laboratory tests performed at the University of Modena and Reggio dell'Emilia where
some of the inventors above designated work.
[0010] It is finally apparent that changes and variants can be made to artefact 1 described
and shown hereof without departing from the protective scope of the present invention.
[0011] Specifically, the section of fibre 3 may differ from that described, and specifically
such section may be polygonal. Furthermore, between reciprocally adjacent pairs of
segments 5 and 6 there may be introduced a third joining segment with a different
angle with respect to segments 5 and 6. It must be underlined that fibres 3 or at
least a certain number of the latter may be reciprocally braided or however a connection
between such fibres 3 may be contemplated so as to determine a well-defined position
of at least a plurality of fibres 3 at a zone of artefact 1.
1. A building artefact of the type comprising a mixture (2) of inert material and of
bonding material and a plurality of plastic material fibres (3) embedded in said mixture
(2), characterised in that said fibres (3) present at least two subsequent segments (5 and 6) which converge
in a convergence point (4).
2. An artefact according to claim 1 characterised in that said segments (5 and 6) are straight.
3. An artefact according to claim 1 and/or 2 characterised in that said convergence point (4) is a sharp edge.
4. An artefact according to at least one of the preceding claims characterised in that the subintended angle between said subsequent segments (5 and 6) is acute.
5. An artefact according to at least one of the preceding claims characterised in that the pair of said subsequent segments is defined by a first segment (5) and by a second
segment (6) of length shorter than that of said first segment (5).
6. An artefact according to claim 5 characterised in that each of said fibres (3) presents a plurality of said first segments (5) alternated
with said second segments (6).
7. An artefact according to claim 5 characterised in that each of said subsequent pairs is connected by means of a third segment.
8. An artefact according to claim 6 characterised in that said first segments (5) of the same said fibre (3) are reciprocally parallel and
characterised in that said second segments (6) of the same said fibre (3) are reciprocally parallel.
9. An artefact according to any of the preceding claims characterised in that the section of said fibre (3) is elliptical.
10. An artefact according to any of the claims from 1 to 8 characterised in that the section of said fibre (3) is polygonal.
11. An artefact according to any of the preceding claims characterised in that the surface of said fibre (3) is rough.
12. An artefact according to any of the preceding claims characterised in that said fibres (3) are reciprocally connected.
13. An artefact according to any of the preceding claims characterised in that said bonding material is a concrete-based material.