[0001] The present invention relates to a beam and block floor. The invention further relates
to a method of producing such a floor and to a beam for use in such a floor.
[0002] Beam and block floors are typically formed by an array of equidistantly arranged
horizontal beams provided with substantially horizontal support surfaces, a plurality
of blocks between the beams resting on the support surfaces and concrete covering
the beams and the blocks. The blocks are generally made of a thermo-isolating material,
such as Expanded Polystyrene (EPS), or any other suitable material, such as ceramic,
clay or concrete. These blocks serve as a mould for the concrete. The blocks can for
example be mainly rectangular blocks, with or without chamfered sections, or they
can be plates or shells, e.g. curved shells, or they can have any other suitable shape.
A metallic reinforcement mesh can be arranged on top of the beams. Concrete is poured
over the beams and blocks. After hardening the different components of the floor cooperate
as a coherent composed structure. Such floors show good structural and isolating performance,
can be constructed relatively quick and involve low expenses. Such floors are typically
used in residential buildings.
[0003] Hitherto, the beams used in such floors are usually beams of pretensioned or reinforced
concrete, which have inverted T-shape cross sections. Such concrete beams are heavy
and difficult to handle. Moreover, such concrete beams are relatively fragile, so
during assembly of the floor such concrete beams may need additional temporary supports
to avoid downward bending of the floor caused by its own weight, which would substantially
deteriorate the structural performance of the resulting floor.
[0004] NL 1012339 discloses a block and beam floor using light weight beams of a fibre reinforced polymeric
material. It has been found that such beams have limited load capacity and need additional
support during building of the floor.
[0005] WO 2009/109893 discloses a floor using beams made of two sheet metal parts with L-shaped cross section,
e.g. of galvanised steel, arranged back to back to form an inverted T-shape. The two
parts can be connected, e.g., by welding. Such beams have a relatively low load capacity
and need additional temporary supports during assembly of the floor. Moreover, the
welding connections and the ends of such beams are easily exposed to corrosion.
[0006] It is an object of the invention to provide a floor which overcomes the aforementioned
problems.
[0007] The object of the invention is achieved with a floor comprising blocks, beams provided
with support surfaces for supporting the blocks and a layer of concrete structurally
connecting the beams and covering the blocks, wherein at least a part of the beams
are formed from a metal sheet folded to form a beam with the desired cross section,
wherein the cross sectional ends of the metal sheet are embedded in the concrete.
[0008] By embedding the sheet ends, it becomes possible to attach these ends to each other
without enhancing the risk of local corrosion. This way, beams can be folded from
a single metal sheet with a cross section combining low weight with high load capacities.
Since the sheet ends are embedded in the concrete and protected against corrosion,
a wide range of connections can be used to attach the sheet end to each other. Suitable
connection means are for instance a weld, spot welds, dowels, rivets and/or clinch
connections, e.g., clinch connections of the type provided by the German company Tox
Pressotechnik. Preferably, the sheet ends overlap each other.
[0009] Preferably, also the outer ends of the beams are embedded in the concrete. These
outer ends form typical spots for corrosion. By embedding these spots in the concrete
layer these outer beam ends can effectively be protected against corrosion.
[0010] The metal sheet can for instance be a steel sheet. Preferably the steel is galvanized
or provided in any other suitable way with a protective layer, such as a zinc layer.
The steel can for instance be cold rolled galvanized steel.
[0011] To enhance the structural cooperation between the concrete layer and the beams and
to optimize load transfer between the floor components, the beam parts which are embedded
in the concrete layer can be provided with local deformations, such as impressions.
[0012] The beams can be dimensioned in such a way that in use the top sides of the beams
protrude above the blocks. This way one or more reinforcement meshes can be placed
on the top sides of the beams, at a distance above the blocks. Such meshes may considerably
enhance the load capacity of the floor as a constructional unit.
[0013] The beams will generally have a symmetrical cross-section, although non-symmetrical
configurations can also be used, if so desired.
[0014] In cross section the beams can for example enclose one or more hollow spaces extending
in longitudinal direction of the beam. In such a case a wall of at least one of the
hollow spaces may border the lower side of the beam. This way, the lower side can
be used for providing fastening means, e.g., to attach further constructional elements,
such as piping, ceiling elements, etc..
[0015] In a particular embodiment the beam comprises two such hollow spaces, e.g., an upper
hollow space and a lower hollow space. Optionally, the hollow spaces can be triangular
in cross section. The triangular spaces can be configured to point towards each other.
A web may bridge the two triangular hollow spaces. In that case, the overlapping cross
sectional ends of the metal sheet are preferably located at a section of the web which
is embedded in the concrete layer. The support surfaces of the beam for carrying the
blocks may extend from both lateral sides of the lower surface of the lower hollow
space. The triangular hollow space may for instance be smaller than the upper hollow
space.
[0016] Such a beam can be folded from a metal sheet in such a way that the web and the support
surfaces are double walled while the walls of the hollow spaces are single walled.
[0017] This cross-sectional configuration of the beams makes it possible to provide beams
combining light weight with high load capacity. The beams can for instance have a
weight of 7,5 kg/m or less, e.g., 7 kg/m or less or even 6,5 or less and still have
a load capacity which is sufficient to avoid the need for auxiliary supports during
construction of the floor, even when people need to walk over the blocks resting on
the support surfaces of the beams before the concrete is poured. For normal beam lengths
the weight of the beams can be kept well below weights (presently 28 kg) for which
present-day legislation in most European jurisdictions would prescribe the use of
auxiliary lifting means.
[0018] The blocks will generally be thermal isolation blocks, e.g. of expanded polystyrene,
although other block types can also be used if so desired, such as ceramic materials,
clay, plastic or concrete or any other suitable formwork material. The blocks are
typically provided with shoulders resting on the support surfaces provided by the
beams. Optionally, the blocks can be provided with a lateral edge gripping around
the lower surface of the beam and abutting the lower part of the side edge of an adjacent
block. This way, an isolation layer can be obtained which is not interrupted by the
beams and the formation of thermal bridges can effectively be prevented. The beam
material is better isolated from cold coming from below, so condensation on the beam
surfaces is substantially reduced.
[0019] The present invention will be elucidated with reference to the figures wherein:
- Figure 1:
- shows in cross section an embodiment of a floor according to the present invention;
- Figure 2:
- shows in cross section a beam of the floor of Figure 1;
- Figure 3:
- shows in cross section a detail of the floor of Figure 1 near an outer end of a beam;
- Figure 4:
- shows in cross section a second exemplary embodiment of a floor according to the present
invention.
[0020] Figure 1 shows in cross section a floor 1 made of blocks 2, equidistantly arranged
horizontal beams 3 and a layer of concrete 4 which covers the blocks 2 and beams 3.
At both lateral sides the beams 3 are provided with support surfaces 5 for supporting
the blocks 2. The hardened concrete layer 4 structurally connects the beams 3 and
cooperates with the beams 3 to function as a single structural unit. The ends of the
beams 3 are supported by parts of the buildings construction or foundation (not shown).
[0021] As is particularly clear from Figure 2 the beams 3 are formed from a steel sheet
material 31 folded to form a beam with the desired cross section. The steel sheet
31 is galvanized to form a protective zinc layer. The ends 32, 33 of the sheet metal
31 overlap and are connected, e.g., by welding, spot welding, rivet, dowel or clinch
connections. In the final floor the connected ends 32, 33 of the metal sheet 31 are
fully embedded within the concrete layer 4. This way, the connected ends 32, 33 are
effectively protected against corrosion. Also the outer beam ends (not shown) of the
beams 3 are fully embedded in the concrete layer 4. These ends are typically not or
not fully protected by galvanization. The embedding concrete protects these beam ends
against corrosion.
[0022] In cross section the beams 3 enclose an upper hollow space 34 and a lower hollow
space 35. Both hollow spaces 34, 35 extend in longitudinal direction of the beam 3
over the full length of the beam 3.
[0023] The upper hollow space 34 is triangular in cross section and comprises an upper surface
36 which is substantially horizontal in use and two symmetrically arranged side walls
37, 38, both converging downwardly under an angle of about 45 degrees with the upper
surface and under a 90 degrees angle with each other.
[0024] The lower hollow space 35 comprises a lower surface 39 which is substantially horizontal
in use and two symmetrically arranged side walls 40, 41, both converging upwardly
under an angle of about 45 degrees with the lower surface 39 and under a 90 degrees
angle with each other. The lower surface 39 of the lower hollow space 35 borders the
lower side 42 of the beam 3.
[0025] The lower side 42 of the beam 3 extends at both lateral sides of the lower surface
39 of the lower hollow space 35 to form the support surfaces 5 for supporting the
blocks 2. The lower surface 39 of the lower hollow space 35 forms the middle section
of the lower side 42 of the beam 3 and spans about 10 - 50 %, e.g., about 25 - 40
%, e.g., about one third of the lower side 42.
[0026] The 90 degrees angular points 43, 44 of the upper and lower hollow spaces 34, 35
point towards each other. A web 45 connects these two points 43, 44. In use the web
45 is substantially vertical. The cross section of the beam 3 is substantially symmetrical,
with a symmetry axis coinciding with the vertical axis of the web 45.
[0027] In the shown embodiment the upper hollow space 34 is larger than the lower hollow
space 35. For instance, the width of the upper surface 36 of the upper hollow space
34 can be about 1,5 - 3 times, e.g. about 2 times the width of the lower surface 39
of the lower hollow space 35.
[0028] The web 45 comprises a lower section 46 and an upper section 47. In use the lower
section 46 is located between two adjacent blocks 2, while the upper section 47 is
embedded in the concrete layer 4. The overlapping ends 32, 33 of the metal sheet 31
are positioned in the upper section 47 of the web 45. To enhance structural cooperation
between the concrete layer 4 and the beam 3, the upper section 47 of the web 45 is
provided with local deformations, such as spherical impressions 48.
[0029] The top surfaces 36 of the beams 3 protrude above the blocks 2. A metallic reinforcement
mesh 49 rests on the top surfaces 36 of the beams 3 (see Figure 1). The mesh 49 is
fully embedded in the concrete layer 4.
[0030] The disclosed geometry makes it possible to use beams 3 weighing 7,5 kg/m or even
less and still having sufficient load capacity avoiding the need to use auxiliary
supports during assembly of the floor. The load capacity of the beams 3 can be sufficient
to allow workmen to walk over the blocks 2 resting on the support surfaces 5 of the
beams 3 before the concrete is poured. Hence, during assembly the beams 3 only need
to be supported at positions where the final floor is supported after hardening.
[0031] The blocks 2 are made of an isolating material, such as expanded polystyrene, EPS.
The blocks 2 comprises a middle section 21 with a rectangular cross section bordered
by two downwardly slanting longitudinal edges 22, 23 both provided with a shoulder
24 resting on the support surfaces 5 of the beans 3. One longitudinal side 22 is provided
with a lateral extension 25 extending below the shoulder 24, fully covering the lower
side 42 of the beam 3 and abutting the lower side of the slanting edge 23 of and adjacent
block 2. This way, the isolation layer formed by the blocks 2 is not interrupted by
the beams 3 and the formation of thermal bridges can effectively be prevented.
[0032] The floor 1 is finished with a screed top layer 26.
[0033] As shown in Figure 3 the outer end 27 of the beam rests on a foundation 28 where
it faces a wall section 29. A gap 30 between the outer end 27 and the wall section
29 ensures that the outer end 27 of the beam 3 is fully embedded in the concrete layer
4.
[0034] Figure 4 shows an alternative embodiment of a floor 50 according to the invention.
Parts which are the same as in the embodiment of Figure 1 are indicated with the same
referential numbers. Beams 3 comprise support surfaces 5 carrying blocks 51 formed
by curved shells 51, e.g., of a concrete or plastic material. The shells 51 and beams
3 are covered by a concrete layer 4 finished by a screed top layer 25. As shown in
more detail in Figure 5, the lower side surface 39 of the lower hollow space 35 of
the beams 3 is provided with fastening elements 52 for a ceiling element 53. Optionally,
the lower surface 39 can also be used for fastening other constructional elements,
such as piping and the like. In the drawing of Figure 4 pipe lines 54 are arranged
between the ceiling 53 and the shells 51.
1. Floor comprising blocks, beams provided with support surfaces for supporting the blocks
and a layer of concrete structurally connecting the beams covering the blocks, wherein
at least a part of the beams are formed from a metal sheet folded to form a beam with
the desired cross section, wherein the cross sectional ends of the metal sheet are
embedded in the concrete.
2. Floor according to claim 1 wherein the outer ends of the beams are embedded in the
concrete.
3. Floor according to claim 1 or 2 wherein the ends of the metal sheet are connected
by means of a weld, spot welds, dowels, rivets and/or clinch connections and, optionally,
wherein the connected ends overlap.
4. Floor according to any one of the preceding claims wherein the metal sheet is provided
with a protective layer, e.g., a zinc layer.
5. Floor according to any one of the preceding claims wherein at least a part of the
beams enclose in cross section one or more hollow spaces extending in longitudinal
direction of the beam, wherein a wall of at least one of the hollow spaces borders
the lower side of the beam.
6. Floor according to claim 5 wherein the lower side of the beam is provided with fastening
means.
7. Floor according to any one of the preceding claims wherein one or more of the parts
of the beams embedded in the concrete are provided with impressions.
8. Floor according to any one of the preceding claims wherein the top sides of the beams
protrude above the blocks and wherein one or more reinforcement meshes rest on the
top sides of the beams.
9. Method of manufacturing a floor according to any one of the preceding claims wherein
beams are used formed of a single metal sheet folded to form a beam with a desired
cross section, wherein the ends of the metal sheet overlay each other, the ends being
embedded in the concrete.
10. Method according to claim 9 wherein beams are used weighing at most 7,5 kg/m, preferably
less than 7 kg/m, wherein during assembly of the floor the beams are only supported
at positions where the final floor is supported after hardening.
11. Beam for a floor according to any one of claims 1 - 8, formed from a metal sheet folded
into a desired cross section, wherein the ends of the metals sheet are connected to
each other, e.g., with a weld, spot weld, clinch and/or dowel connection.
12. Beam according to claim 11 at partly provided with a protective layer, e.g., a zinc
layer.
13. Beam according to claim 11 or 12 wherein the cross section of the beam encloses at
least one, e.g., two hollow spaces extending in longitudinal direction of the beam.
14. Beam according to claim 13 wherein at least one of the hollow spaces borders a lower
face of the beam and wherein the beam comprises a support surface at both sides of
the hollow space.
15. Beam according to claim 14 wherein the beam comprises a second hollow space bordering
an upper surface of the beam and wherein a web bridges the two hollow spaces, wherein
the ends of the metal sheet overlay each other at the bridging web.