[0001] The present invention relates to a connector for mixed constructions in timber and
concrete, particularly floor and roof slabs and the like.
[0002] In the building field mixed constructions of small dimensions in timber and concrete
are currently widely used.
[0003] In these structures there is the problem of making the timber and concrete cooperate
perfectly with each other.
[0004] The object of the invention is to provide a timber-concrete connector that ensures
perfect static cooperation between said materials.
[0005] Another object of the invention is that of providing such a connector that is simple
in concept and therefore economical, and is easily constrained to a laminate or solid
wood beam either in the workshop or on site.
[0006] These objects are achieved by the connector according to the invention which has
the characteristics listed in attached independent claim 1.
[0007] Advantageous embodiments of the invention are described in the dependent claims.
[0008] The timber-concrete connector according to the invention is substantially cylindrical
in shape and has a base or peg that is housed in a cut made for this purpose in the
wood, and a rod-shaped body protruding therefrom and ending at the top in a widened
head.
[0009] In one embodiment an axial hole passes through the entire connector for the passage
of a screw or special nail able to hold said connector in position in the wood, but
without fulfilling an essentially static function. According to a variant embodiment,
this nail is made in a single body with the connector.
[0010] The connector thus remains firmly stuck to the wooden beam, and its structure prevents
axial sliding of the concrete with respect to the wood, whilst the widened head of
the connector prevents any detachment perpendicularly to the surface of the wooden
beam, with a stabilizer effect.
[0011] Further characteristics of the invention will be made clearer by the detailed description
that follows, referring to a purely exemplary and therefore non-limiting embodiment
thereof illustrated in the appended drawings, in which:
Figure 1 is a schematic perspective cutaway view of a timber-concrete structure using
connectors according to the invention;
Figure 2 is a section of the structure in Figure 1, taken at a connector, along the
line II-II in Figure 1;
Figure 3 is a midline section of the connector alone;
Figure 4 is an axonometric view of the connector.
[0012] Figures 1 and 2 show part of a mixed timber-concrete construction, such as floor
or roof slab, for example.
[0013] The structure is made of laminate wood beams 1, only one of which is shown in the
figures, on which the so-called intermediate means 2 is laid, that is supporting panels
made of tiles, timber or other materials, for subsequent casting of concrete 5. Before
carrying out the concrete casting 5, an electric welded wire mesh 4 that serves to
reinforce the structure is disposed on the intermediate means 2 to a certain height
therefrom.
[0014] To make the timber 1 and the concrete 5 statically cooperating, connectors 10 are
disposed therebetween, the number, positioning and size of said connectors 10 being
calculated on the basis of the structure to be created.
[0015] Each connector 10 has a base or peg 11 that is disposed in a corresponding cut 20
made in the wooden beam 1, a substantially cylindrical body 12, extending upwards,
and a widened head 13. The body 12, which in the embodiment illustrated in the appended
drawings has a slightly conical shape toward the top, has a central hole 14 passing
through it for insertion of a screw or special nail 15 which screws into the wooden
beam 1 beneath, to hold the connector 10 in position, before casting of the concrete
5, but without fulfilling any static function. Alternatively, the nail 15 can be made
in a single body with the connector 10, protruding from the base or peg 11 like a
plug.
[0016] In the example shown, the base or peg 11 of the connector 10 is shaped like a continuous
skirt downwardly tapering to a point, peg known by the name of Appel in other types
of connectors. It is obvious, however, that the peg 11 can be of other types, for
example with a profile shaped like a T (Christoph & Unmack system), a double cone
(Kubler system), in the form of a plate with a plurality of pointed teeth that protrude
from the bottom thereof (Geka system), or of other shapes still, the characteristics
of the connector according to the invention remaining the same.
[0017] The connectors 10 can be preinstalled on the beams 1 in the workshop or they can
also be applied on site, an operation that does not require particular specialized
labour.
[0018] Assembly of the connector 10 according to the invention in fact requires a machined
part on the beam for housing of the peg 11, after which the screw 15 or special nail
is screwed in.
[0019] In the case of the nail being made in a single body with the connector, it is sufficient
to apply a suitable pressure thereon.
[0020] The connector according to the invention is advantageously made of metal with a special
anticorrosive treatment.
1. A connector for mixed timber-concrete constructions, such as floor or roofing slabs
and the like, comprising a base or peg (II) housed in a seat (20) made in the wooden
beam (1), and an elongated body (10) terminating in a widened head (13), embedded
in concrete (5).
2. A connector according to claim 1, characterized in that it has an axial through hole
(14) for insertion of a screw (15) or special nail for fixing the connector (10) to
the wooden beam (1).
3. A connector according to claim 1, characterized in that, protruding from said base
or peg (11), it has a screw or nail (15) made in a single body therewith.
4. A connector according to any one of the preceding claims, characterized in that said
elongated body (10) is substantially cylindrical.
5. A connector according to claim 4, characterized in that said elongated body (12) is
tapered at the opposite end to said base or peg (11).
6. A connector according to any one of the preceding claims, characterized in that said
base or peg (11) consists of a continuous skin tapered downwardly, of the Appel type
(type "A" DIN 1052), or has a T-shaped profile, of the Christoph and Unmack type,
or has a double-cone profile, of the Kubler type, or has a plurality of sharp teeth
that stick into the wooden beam (1), of the Geka type.
7. A method of connecting a mixed timber-concrete structure in a statically cooperating
manner, using a plurality of connectors (10) according to any one of the preceding
claims, consisting in making cuts (20) in the wooden beam (1), disposing the bases
or pegs (11) of the connectors (10) in said cuts (20), fixing the connectors (10)
to the beam (1) by means of screws or special nails (15) passing through a corresponding
central hole (14) in the connectors (10) or made in a single body therewith, and casting
the concrete (5) on the beam (1) prepared with the connectors (10).
8. A method according to claim 7, wherein said connectors (10) are applied to the beams
(1) in the workshop.
9. A method according to claim 7, in which said connectors (10) are applied to the beams
(1) on site.
10. A method according to any one of claims 7 to 9, in which intermediate means (2) of
tiles, wood or the like and possibly a reinforcing electric welded wire mesh (4) is
disposed on said beams (1) before casting of the concrete (5).