U.S. patent application number 16/718477 was filed with the patent office on 2020-07-02 for support element for supporting a window frame.
This patent application is currently assigned to ISO-Chemie GmbH. The applicant listed for this patent is ISO-Chemie GmbH. Invention is credited to Martin Deiss.
Application Number | 20200208400 16/718477 |
Document ID | / |
Family ID | 64949091 |
Filed Date | 2020-07-02 |
United States Patent
Application |
20200208400 |
Kind Code |
A1 |
Deiss; Martin |
July 2, 2020 |
Support Element for Supporting a Window Frame
Abstract
A strip-shaped support element for supporting a window frame
comprises an intumescent material such as expandable graphite or
sodium and/or potassium silicate. In particular, the support
element comprises intumescent material on at least one surface,
optionally on all surfaces, in a thickness of at least 0.25 mm.
Inventors: |
Deiss; Martin; (Abtsgmuend,
DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ISO-Chemie GmbH |
Aalen |
|
DE |
|
|
Assignee: |
ISO-Chemie GmbH
Aalen
DE
|
Family ID: |
64949091 |
Appl. No.: |
16/718477 |
Filed: |
December 18, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E04B 1/943 20130101;
E04B 1/945 20130101; E04B 1/7641 20130101; E06B 1/02 20130101; E06B
1/6023 20130101; E06B 1/003 20130101 |
International
Class: |
E04B 1/94 20060101
E04B001/94 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 31, 2018 |
EP |
18 215 948.3 |
Claims
1. A strip-shaped support element for supporting a window frame,
the strip-shaped support element having a first side surface
extending in a longitudinal direction and configured to rest
against a wall, and a second side surface extending in the
longitudinal direction, wherein the second side surface is
substantially perpendicular to the first side surface and is
configured to support the window frame, wherein the support element
is made of a load-bearing material, wherein the support element
comprises intumescent material on at least a surface thereof in a
thickness of at least 0.25 mm, which material is selected from the
group consisting of: (a) expandable graphite in an amount of 5-70%,
and (b) sodium and/or potassium silicate in an amount of
10-30%.
2. The strip-shaped support element according to claim 1, wherein
the support element also comprises rigid foam, selected from the
group comprising rigid polyurethane foam.
3. The strip-shaped support element according to claim 1, wherein
at least one layer parallel to the second side surface of the
support element comprises intumescent material.
4. The strip-shaped support element according to claim 1, wherein
the support element comprises intumescent material on at least one
surface which is a third side surface extending in the longitudinal
direction, wherein the third side surface is adjacent to the second
side surface on a side opposite the first side surface.
5. The strip-shaped support element according to claim 1, wherein
the support element comprises a layered structure with at least one
outer layer with intumescent material and at least one layer
without intumescent material.
6. The strip-shaped support element according to claim 5, wherein
the outer layer with intumescent material is fastened to the layer
without intumescent material by adhesion or by screws.
7. The strip-shaped support element according to claim 5, wherein
the support element comprises intumescent material in a thickness
of between 0.25 mm and 10 mm, and wherein the intumescent material
is expandable graphite in an amount of 20-70%.
8. The strip-shaped support element according to claim 1, wherein
the support element comprises intumescent material in a thickness
of at least 10 mm, and wherein the intumescent material is
expandable graphite in an amount of 5-20%.
9. The strip-shaped support element according to claim 1, wherein
the support element comprises intumescent material throughout, and
wherein the intumescent material is expandable graphite in an
amount of 5-20%.
10. The strip-shaped support element according to claim 9, wherein
the support element comprises rigid polyurethane foam with 5-10%
expandable graphite, obtainable by pressing a starting material, in
that expandable graphite flakes in a polyurethane and/or
polyisocyanate matrix are pressed in a pressing direction P,
wherein the pressing direction P is perpendicular to the second
surface of the support element.
11. The strip-shaped support element according to claim 1, wherein
the support element comprises intumescent material in a thickness
of at least 10 mm, and wherein the intumescent material is sodium
and/or potassium silicate in an amount of 10-30%.
12. A building section comprising: a wall; at least one
strip-shaped support element having a first side surface extending
in a longitudinal direction and configured to rest against a wall,
and a second side surface extending in the longitudinal direction,
wherein the second side surface is substantially perpendicular to
the first side surface and is configured to support the window
frame, wherein the support element is made of a load-bearing
material, wherein the support element comprises intumescent
material on at least a surface thereof in a thickness of at least
0.25 mm, which material is selected from the group consisting of:
(a) expandable graphite in an amount of 5-70%, and (b) sodium
and/or potassium silicate in an amount of 10-30%; wherein the
support element is arranged laterally from the wall, and wherein
the support element is fastened to the wall by means of at least
one fastening element, wherein the first side surface of the
support element rests against the wall; and a window frame, which
is supported at least partially on the second surface of the
support element.
13. The building section according to claim 12, wherein the
building section comprises a plurality of the support elements,
wherein: (a) support elements butt directly against each other
horizontally, so that the at least one surface comprising
intumescent material forms a horizontal fire control barrier
without interruption; and/or (b) a fire-retardant layer is
introduced horizontally between the support elements, wherein the
fire-retardant layer is selected from the group comprising mineral
wool.
Description
FIELD OF THE INVENTION
[0001] The invention relates to a strip-shaped support element for
supporting a window frame, especially an outer face wall
installation casing.
[0002] The invention also relates to a section of a building or a
building comprising at least one support element and also the use
of the support element for making a building fire-retardant, e.g.,
as a fire barrier, i.e., for preventing the spread of flames and/or
smoke gas upward along the facade of the building, or in/on a
composite thermal insulation system, and/or for decreasing the rise
in temperature on the side of the support element facing away from
the fire.
[0003] Support elements for supporting a window frame, especially
outer face wall installation casings, have been used for some years
in conjunction with composite thermal insulation systems to extend
a wall opening for a window artificially outward. According to EP 2
639 394 A2, a support part of rigid, load-bearing foam is screwed
laterally to the wall and serves, especially at the bottom, to
support the window frame to be inserted. Thus, for example, an
outer wall cooperates with the inner wall to form an intermediate
space, in which the support element is arranged. The load-bearing
support element with a more-or-less triangular cross section can be
supplemented by an insulation part, which consists of hard flexible
foam, for example, and which cooperates with the support element to
form a two-part body with a preferably rectangular cross
section.
[0004] US 2015/0211285 A1 makes available a support element which
can be transported and installed very easily.
[0005] One problem with the use of a composite thermal insulation
system (or external wall insulation system, EWIS), in which an
outer wall installation casing is usually used, is the
combustibility of frequently used insulation materials, which
comprise, for example, rigid polystyrene foam such as rigid
expanded polystyrene foam (EPS) and rigid extruded polystyrene foam
(XPS). In particular, when a house is on fire, the flames can
spread upward via the facade or possible gaps between the inner
wall and the outer wall to the next-higher story, which can lead to
the development of a chimney effect.
[0006] US 2018/0312656 A1 describes a functional material which
comprises a thermosetting material such as rigid PUR/PIR or
phenolic foam, a binder material for binding the thermosetting
material, and an additive such as expandable graphite, which is
intended to improve the combustion behavior. This material is
intended to be used in particular in the form of panels as, for
example, thermal insulation elements for outer wall insulation
systems or for facade insulation or roof insulation. Coating or
impregnating flammable thermal insulation elements and other
structural parts such as sealing tape with flame retardants is also
known from the prior art; see for example, US 2018/0236754 A1, EP 2
963 198 A1, DE 20 2017 102 227 U1, and U.S. Pat. No. 6,054,513 DE
20 2012 103 609 U1 describes polystyrene foams which are furnished
with hexabromocyclododecane (HBCD) as a flame retardant, or which
are provided with a jacket of polyurethane foam, which contains
flame retardants such as TCPP (trichloropropyl phosphate), TBBPA
ester (tetrabromobisphenol ester), or PBDE (pentabromodiphenyl
ether).
[0007] Fire control barrier elements made of metal, for example, or
of mineral wool or polymer materials are also already known from
the prior art; their use in a thermal insulation system is intended
to prevent the danger that the fire might spread to the next-higher
story. EP 2 088 253 A describes a fire control barrier of
polyurethane foam (PUR foam) or polyisocyanate foam (PIR foam) with
a homogeneous bulk density in the range of 26 to 80 kg/m.sup.3. In
Germany, for example, fire control barriers must be installed in
every second story of a high-rise building; in some other
countries, they are required in every story.
SUMMARY OF THE INVENTION
[0008] It is an object of the present invention to improve the fire
control of additional structural elements of buildings, e.g., of
outer wall installation casings, and/or to use such elements to
con-tribute to fire control, in particular within the scope of fire
control barriers.
[0009] According to an aspect of the invention a strip-shaped
support element is provided, which is adapted to the support of a
window frame with a first side surface extending in the
longitudinal direction, which can serve to rest against a wall, and
a second side surface extending in the longitudinal direction,
which is substantially perpendicular to the first side surface, and
which can serve to support the window frame, wherein the support
element is made of a load-bearing material, and wherein the support
element comprises intumescent material on at least one surface,
optionally on all surfaces, with a thickness of at least 0.25 mm.
The intumescent material, i.e., the material with an expansion
effect, is selected from the group consisting of:
[0010] (a) expandable graphite in an amount of 5-70%, and
[0011] (b) sodium and/or potassium silicate in an amount of
10-30%.
[0012] The intumescent material is preferably present in a
thickness of at least 10 mm, and preferably expandable graphite is
present in an amount of 5-20%, more preferably of 5-15% or 7-10%.
Within the scope of the invention, the percentages, unless
otherwise indicated, are always defined on a weight/weight basis.
Expandable graphite can be produced from the naturally occurring
material graphite. A graphite flake consists of layers of carbon
atoms arranged in honey-comb fashion. Within the layers, the atoms
are very strongly connected by covalent bonds. Between the layers,
the bonding forces are quite weak, so that molecules can be
intercalated between the layers of graphite. The intercalation of
an acid, usually sulfuric acid, converts the graphite into
expandable graphite. When expandable graphite is heated, the
graphite flakes expand to many times their original volume as soon
as the temperature reaches approximately 140.degree. C.; the exact
temperature depends on the quality of the graphite. The
volatilization of the intercalated compounds drives the graphite
layers apart like an accordion. The expanded flakes have the
appearance of little "worms" and are usually several millimeters
long (Vijay J. Bhagat: Behavior of expandable graphite as a flame
retardant in flexible polyurethane foam. Presented at: Polyurethane
Foam Association (PFA), Arlington, Va., USA, May 10, 2001). The
expansion rate of expandable graphite is approximately 30-400
cm.sup.3/g.
[0013] The particles size can be in the range between 80%<75
.mu.m and 80%>1,500 .mu.m. More than 60% of the particles of the
expandable graphite are usually at least 100 .mu.m in size or at
least 500 .mu.m in size; the average particle sizes are preferably
500-1,500 .mu.m. The larger the particle size, the greater the
expansion pressure which develops in the event of a fire. Large
particle sizes (300-1,500 .mu.m) are therefore used primarily when
a large volume is to be blocked up with foam. The particle size can
be determined by means of a sieve analysis according to DIN 66 165,
for example.
[0014] The starting temperature of the expansion is at least
140.degree. C., preferably at least 160.degree. C., at least
170.degree. C., or at least 180.degree. C. The starting temperature
of the expansion and the expansion rate can be influenced by the
fineness of the graphite. On exposure to heat, the expandable
graphite expands and forms an intumescent layer on the surface of
the material. This slows down the spread of the fire and
counteracts the consequences of a fire which are dangerous for
people such as the formation of toxic gases and smoke. The
expandable graphite is preferably present in an amount of 5-10%,
which is sufficient to achieve the fire-retarding effect. If too
much expandable graphite is used, different effects are caused,
which can have a negative impact on the products desired here. Such
a negative effect is an increase in the thermal conductivity of the
graphite (Ozturk 2012, Highly Filled Graphite Polymer Compounds for
Uses in Heat Management. Dissertation, Technical University of
Darmstadt).
[0015] It has been found that the use of expandable graphite offers
additional advantages besides the characteristics useful for fire
control; for example, materials produced with it generate less dust
when processed by operations such as sawing. Such materials can
therefore be used to minimize dust formation during processing.
[0016] Alternatively or in addition, the intumescent material can
be sodium and/or potassium silicate in an amount of 10-30%,
preferably of 10-20%. This waterglass can be produced by
solidification from a melt. Particles, e.g., particles with a size
of approximately 0.1-5 mm, with an average size of 1 mm, can be
embedded in the foam matrix to achieve advantages.
[0017] The support element also comprises a least one polymer,
preferably a thermoset. A support element with rigid foam, e.g.
rigid PUR foam, preferably rigid polyurethane/polyisocyanate foam,
rigid PIT foam, or rigid phenolic foam, offers especially good
mechanical and heat-insulating properties. In a preferred
embodiment, the support element comprises comminuted rigid PUR
and/or rigid PIR foam and/or comminuted rigid phenolic foam as the
thermosetting material, which is bound at least under the action of
heat, for example, by a binding material, preferably PUR and/or PIR
which is in the form of a liquid or paste at room temperature
(25.degree. C.). Within the scope of production, these components
are treated jointly with the introduced intumescent material by
heat and/or pressure, usually by both. The particle size of the
intumescent material is preferably 0.1-2 times the size of the
comminuted rigid foam particles, best of all approximately the same
size, for the purpose of ensuring good mixability.
[0018] Fibrous materials, e.g., mineral fibers or nonmineral
fibers, can also be introduced into the starting material before
the pressing step; carbon fibers can be used here.
[0019] The starting material is pressed in particular in a pressing
direction P. The starting material, which comprises expandable
graphite, for example, is preferably pressed in a pressing
direction P to a bulk density of 500-600 kg/m.sup.3. The support
element consists substantially of the polymer, e.g., a rigid
PUR/PIR foam, as described herein, in addition to the intumescent
material. The proportion of the polymer (comminuted rigid foam and
binder material together) can be 40-97%, for example; in
combination with expandable graphite, it can be, for example,
70-97%, preferably 80-95% or 90-95%. Because recycled thermal
insulation panels can be used as the comminuted thermoset material,
contaminants such as the foil material, e.g., aluminum foil,
ap-plied to these panels can be introduced. The support element is
preferably halogen-free. The amount of binder material is usually
no more than 20%, and the amount of comminuted rigid foam is
usually approximately 60-75%.
[0020] Panels produced by the pressing step can be cut into
strip-shaped support elements, wherein the production of L-shaped
support elements can be accomplished by milling, for example, or by
bonding a wider element to a narrower one.
[0021] In one embodiment, the support element consists of a
substantially homogeneous material; that is, the intumescent
material is introduced not just into one or more layers but rather
continuously throughout. The whole or the entire support element
therefore consists substantially of the mixture with the
intumescent material. For example, the support element can consist
of a polymer, especially one based on PUR or PUR/PIR such as a
rigid polyurethane foam, together with expandable graphite (e.g.,
5-10%); the element can be produced by pressing a starting
material, in that expandable graphite flakes in a polyurethane
matrix are pressed in a pressing direction P to a bulk density of
500-600 kg/m.sup.3. In a preferred embodiment, the support element
consists of comminuted rigid PUR and/or PIR foam, which is bound by
a binding material, e.g., PUR and/or PIR in the form of a liquid or
paste. As part of the production process, these components are
treated together with the introduced intumescent material, e.g.,
expandable graphite, by pressure, optionally at elevated
temperature, in a pressing direction P. The bulk density of the
material is, for example, 300-1,000 kg/m.sup.3, 500-600 kg/m.sup.3,
or approximately 550 kg/m.sup.3.
[0022] The material used preferably exhibits a combustion behavior
according to at least one of the reaction-to-fire classes C defined
in DIN EN 13501-1 and/or correspondingly to at least one
construction material class B1 according to DIN 4102-1 and thus is
classified as flame-retardant.
[0023] The inventors discovered that, in a fire, e.g., on exposure
to flame for 30 minutes at 180.degree. C., the intumescent material
on the side facing the fire expands from a layer with a thickness
of approximately 10 mm to form an insulating layer. In one
embodiment, the support element therefore comprises on at least one
surface, optionally on all surfaces, intumescent material in a
thickness of at least 10 mm. This is advantageously present
substantially over the entire plane or over the entire plane of
this surface. The intumescent material, i.e., the particles of this
intumescent material, are distributed substantially homogeneously
at least within this thickness. The intumescent material in this
embodiment is not a coating on the surface of the support element
but rather is embedded in the matrix of the support element.
[0024] In a preferred embodiment, at least one layer parallel to
the second side surface of the support element comprises the
intumescent material, preferably the second side surface of the
support element. The second side surface of the support element
extending in the longitudinal direction is substantially
perpendicular to the first side surface, which can serve to contact
a wall. The second side surface can serve to support a window
frame.
[0025] The longitudinal direction is defined by the longest
dimension of the strip-shaped element. The strip-shaped element can
be present without any connection to any other elements, but it can
also be already installed, e.g., in a section of a building,
perhaps as an outer wall installation casing for a window, for
example, or for a door.
[0026] In the installed state as a casing, perhaps as an outer wall
installation casing, the second side surface of the support element
forms the inside surface of the casing facing the window frame.
Thus, in a fire, the exterior area of this side surface is exposed
to the flames to a pronounced degree, especially above the window
opening, from which, in a fire, flames can spread. A
fire-inhibiting or fire-retardant surface at this point, which
comes about through the intumescent action of the material, e.g.,
the expansion of the expandable graphite, can thus prevent the
flames from spreading to material located above the window opening,
e.g., combustible insulating material of a composite outer wall
insulation system, or can at least significantly delay such spread.
Even in the case of a fire which spreads within the composite outer
wall insulation system, the support element thus offers an
effective barrier, which can prevent or significantly delay any
further upward propagation.
[0027] On the side facing the window frame, the expansion of the
expandable graphite also effectively prevents a sealing tape, which
is usually attached between the casing and the window frame, from
having a fire-promoting effect. Any gaps which may form are sealed
off by the expansion.
[0028] If, alternatively or in addition, the layer comprising the
intumescent material parallel to the second side surface of the
support element is not the second side surface itself, then the
side surface in question will be the side surface facing away from
the window opening in the installed state, which therefore means
that the surface in question is the bottom surface of the casing,
for example, which also represents an effective horizontal barrier
against the upward spread of a fire in or on a building.
[0029] Other locations critical with respect to the spread of fire
are the joints which can be present between the casing and an
optional outer wall present in the building. Combustible insulating
materials located between the main wall and the outer wall can
ignite rapidly in the event of a fire, wherein the fire, if no
additional structural measures have been taken, can spread upward
very quickly through this intermediate space. For example, because
of different distances between the main wall and the outer wall or
because of the need for a gap to ensure the rear ventilation of the
outer wall, joints are often present in a building between the
casing and the outer wall, which can often have a width of some
millimeters, e.g., 10-200 mm. The vertical spread of a fire through
these joints can be prevented or at least significantly delayed.
The penetration of smoke through such joints can also be
minimized.
[0030] According to an aspect of the invention, the support element
can comprise intumescent material on at least one surface which
represents a third side surface extending in the longitudinal
direction, this third surface being adjacent to the second side
surface on the side opposite the first side surface. The third side
surface is preferably parallel to the first side surface, e.g., in
the case that the support element is in the form of an L. In the
installed state, this side can thus be facing the outer wall. When
the expandable graphite on this side surface expands, a joint
potentially located there is advantageously sealed off, so that the
spread of flames through the joint can be prevented. This advantage
is also offered by a support element with a triangular shape,
although to a lesser extent, depending on the angle.
[0031] Substantially all surfaces (e.g., at least 90% of the
surface area) or all surfaces of the support element comprise the
intumescent material. Optionally, the first side surface, which can
serve to rest against a wall, comprises no intumescent material,
because the wall usually does not consist of a combustible
material.
[0032] The intumescent material can be present in a thickness of at
least 10 mm, approximately in a thickness of 11-50 mm, 12-40 mm,
15-30 mm, or 10-20 mm. Then the amount of expandable graphite is
preferably in the range between 5 and 20%.
[0033] Alternatively, the intumescent material can be present in a
thickness of between 0.25 mm and 10 mm, preferably between 0.5 mm
and 5 mm, more preferably between 1 mm and 3 mm. In this case, the
amount of expandable graphite is between 20 and 70%, preferably
between 30 and 60%.
[0034] Preferably at least all surfaces of the support element
except for the first side surface comprise the intumescent
material, or all surfaces of the support element comprise it.
[0035] As the inventors have been able to show, however, it is not
mandatory that intumescent material also be present in the interior
of the element. The support element can therefore comprise a
layered type of structure. In one embodiment, the support element
comprises at least one layer with a load-bearing property which
exceeds the load-bearing property of the material on the surface
comprising the intumescent material. An interior layer of this type
capable of bearing heavy loads can, for example, comprise a
compressive stress at 10% compression of 2 to 15 MPa, preferably of
4-8 MPa, or especially preferably 6 to 8 MPa, according to DIN EN
826. It can comprise fibrous material, for example, such as carbon
fibers and/or glass fibers. The interior material can,
alternatively, comprise substantially the same load-bearing
capacity as the outer material. Optionally, the interior material
consists of the same material as the outer layer(s) except for the
intumescent material. In this case, the layered structure leads in
particular to a cost reduction, because less intumescent material
is required.
[0036] A layered construction can be produced by connecting the
various layers together (e.g., by bonding them together with an
adhesive or by screwing them together). It is also possible,
however, to produce a layered construction in that the different
layers of comminuted rigid PUR and/or PIR foam, i.e., outside
layers with intumescent material (e.g. expandable graphite) and
inside layers with no intumescent material, are mixed with a binder
such as PUR and/or PIR liquid or paste, and, as part of the
production process, pressed together under pressure and optionally
at elevated temperature in a pressing direction P, which is
perpendicular to the direction of the layers. The outer layers with
intumescent material comprise a thickness of at least 10 mm. The
support elements can be produced from panels formed in this
way.
[0037] The support element is made of a load-bearing material; that
is, it comprises overall a load-bearing property or a compressive
strength which is at least sufficient to support a window. The
compressive stress at 10% compression is preferably 2-15 MPa,
especially 4-8 MPa, or 6-8 MPa according to DIN EN 826.
[0038] As the inventors discovered, the pressing direction P during
the production of the raw material for the support element has an
influence on the structure of the raw material and thus also on the
properties of the support element on exposure to fire. Various
orientations attributable to production conditions are possible
both for support elements made of a homogeneous material and for
those with a layered structure. In particular, the support element
can be configured in such a way that the pressing direction P used
during production is perpendicular to the first side surface of the
support element, or so that the pressing direction P relevant to
production is perpendicular to the second side surface of the
support element.
[0039] It was discovered that the expansion of the intumescent
material on a surface perpendicular to the pressing direction P
leads to greater dimensional increase during a fire than it does on
a surface parallel to the pressing direction P. As described
herein, 30 minutes of exposure to flame causes an approximately
1-cm-thick layer of expandable graphite on a surface perpendicular
to the pressing direction P to expand into an approximately
8-cm-thick insulating layer of expanded graphite. In contrast, 30
minutes of exposure to flame, as described herein, causes an
approximately 1-cm-thick layer on the surface parallel to the
pressing direction P to form an insulating layer of expanded
graphite only about 4 cm thick.
[0040] The support element is preferably configured so that the
pressing direction P is perpendicular to the second side surface of
the support element. The support element can in particular comprise
rigid polyurethane foam, preferably with 5-10% of expandable
graphite, obtainable by pressing a starting material in which
expandable graphite flakes in a polyurethane and/or polyisocyanate
matrix are pressed in a pressing direction P to obtain a bulk
density of 500-600 kg/m.sup.3, wherein the pressing direction P is
perpendicular to the second side surface of the support element.
During a fire, this offers two essential advantages:
[0041] First, an especially thick insulating layer of expanded
graphite is formed on the surface of the support element which is
parallel to the second surface of the support element, namely, on
the surface which is especially important for fire control, as
described herein, especially for the prevention of the upward
spread of flames. As a result, a burn-through is prevented or at
least significantly delayed.
[0042] Second, expansion occurs toward the main wall and toward the
outer wall; this expansion is sufficient to seal off any joints
which may be present. Nevertheless, the expansion and thus also the
pressure on the main wall or outer wall are weaker than they would
be if the orientation of the support element were reversed. As a
result, a lighter load is exerted on the structural integrity of
the adjacent construction elements. During a fire, there is less
movement in the body of the building. The formation of cracks in
the outer wall, which could allow the fire to spread or parts of
the building to fall down, is minimized.
[0043] An alternative embodiment is the application of a thin outer
layer with intumescent material in a thickness of between 0.25 mm
and 10 mm, preferably between 0.5 mm and 5 mm, more preferably
between 1 mm and 3 mm, to a surface of the support element. For
this purpose, the outer layer is attached to the layer without
intumescent material, preferably adhesively bonded. The outer layer
is preferably in the form of strips. The outer layer can but does
not necessarily have to cover the entire surface area of this side
of the support element. In these cases, the intumescent material
must comprise expandable graphite in an amount of 20 to 70%,
preferably of 30 to 60%.
[0044] Because the support element is itself a good thermal
insulator, it can be used without any additional insulating
materials. The support element, however, is preferably used
together with an insulating part, which can be bonded to the
support element to improve the thermal insulating capacity. The
insulating part is preferably made of foam or mineral wool,
preferably of hard flexible foam. This foam should preferably be
self-supporting. Thermal insulation materials such as polystyrene,
Styropor, Styrofoam, or Neopur, for example, can be considered. The
insulating part can be made of flexible foam such as hard flexible
foam.
[0045] To facilitate the on-site installation work, at least one
through-hole is introduced in advance through a first web of the
support element, proceeding from the inner side surface to the
first side surface, to accept a fastening element for attaching the
support element to the wall. The installer therefore does not have
to produce the through-hole at the installation site.
[0046] A geometry which is especially preferred is present when the
cross section of the support element has substantially the shape of
an "L". This ensures that the support element has no slanted edges,
which would make it difficult to handle the support element when
producing the through-holes or when inserting fastening elements
into the through-holes.
[0047] In one variant, the support element can also have a
cross-section in the form of a "T", or it could also be a
rectangular.
[0048] The second web usually comprises the second side surface,
and the first and second side surfaces also intersect at the same
angle at that by which the second web projects from the first web.
This pertains in particular to the configuration of the support
element with an L-shaped cross section.
[0049] It is also possible, however, that the first web could also
comprise the second side surface, which would then be arranged
adjacent to the first side surface. This configuration is
unavoidable in the case of a T-shaped cross section, but it can
also be present in an L-shaped support element.
[0050] In one embodiment, a casing, such as an outer wall
installation casing, is provided which comprises several support
elements, each of which comprises a surface comprising intumescent
material. The casing can be part of a section of a building.
[0051] According to another aspect of the invention, a section of a
building with a wall is provided, with at least one support element
arranged laterally from the wall, which support element is attached
to the wall by means of at least one fastening element, so that the
first side surface of the support element rests against the wall;
and with a window frame, at least part of which is supported on the
second side surface of the support element.
[0052] A building section equipped with the support elements
usually comprises a main wall, an outer wall, and a gap between the
main wall and the outer wall. The support elements are usually
arranged in the gap between the main wall and the outer wall and
are attached to the main wall by fastening elements. A window frame
is arranged adjacent to the gap and rests against the second side
surfaces of the support elements. It is possible for only one
support element to be present, which is arranged under the window
frame and thus bears the load of the window. As an alternative to
the outer wall, a layer of thermal insulation attached to the main
wall can be provided, which has an opening for the window. The
support element then projects into this layer of thermal
insulation. The building section can comprise a composite thermal
insulation system, a rear-vented facade, or a double-shell masonry
wall.
[0053] The building preferably comprises a building section and a
composite thermal insulation system, a rear-vented facade, or a
double-shell masonry wall and usually at least one window.
[0054] A building section or a building can also comprise a
plurality of support elements. In one embodiment of the building
section, support elements can advantageously be configured as a
continuous row of horizontal elements in that, for example, they
abut one another directly. Thus at least one surface of the support
element forms a continuous horizontal fire control barrier. This
can be achieved in that a substantially continuous horizontal
window facade is formed, which is installed with the support
elements. Alternatively, it is also possible to provide only a
single continuous support element.
[0055] Alternatively, the support elements can be a certain
distance apart, wherein a fire-retardant layer is introduced
horizontally between the support elements, wherein the layer can
comprise mineral wool or some other material of low
flammability.
[0056] Such fire control barriers can be provided in every story,
for example, or in every second story of the building.
[0057] Another aspect of the invention is the use of a strip-shaped
support element or building section to make a building
fire-retardant. In one embodiment, this use serves to prevent or at
least significantly to delay the upward spread of flames and/or
smoke gas, especially in a composite thermal insulation systems, a
rear-vented facade, or a double-shell masonry wall.
[0058] In another embodiment, this use serves to minimize the
increase in temperature on a side of the support element facing
away from a fire. As described in the example section, it was found
that the temperature increase on a side of the support element
facing away from a fire is considerably smaller than that for a
support element according to the prior art, especially at butt
joints. The support elements can thus be used so that, on exposure
to flames (e.g., at 180.degree. C. according to DIN 1366-4), the
temperature increase on the side facing away from the flames is
minimized at butt joints between adjacent support elements, wherein
the increase is preferably less than 55.degree. C. after 25
minutes.
BRIEF DESCRIPTION OF THE DRAWINGS
[0059] The patent or application file contains at least one drawing
executed in color. Copies of this patent or patent application
publication with color drawings) will be provided by the Office
upon request and payment of the necessary fee.
[0060] FIG. 1 shows cross-sectional views of a first embodiment of
a support element according to the invention, wherein the lower
diagram represents an insulating part during the pivoting
procedure;
[0061] FIG. 2 shows a schematic, cross-sectional view of a building
section, which shows a support element according to FIG. 1 in the
installed state;
[0062] FIGS. 3a-3h show views of alternative support elements
according to the invention;
[0063] FIGS. 4a and 4b show, from the side (above, in the figure),
embodiments of support elements according to the invention with
homogeneously distributed expandable graphite exposed to flames for
30 minutes;
[0064] FIGS. 5a, 5b, and 5c show the results of the flame-exposure
experiments with embodiments of support elements according to the
invention with homogeneously distributed expandable graphite with
an expanded graphite layer on the flame-exposed side;
[0065] FIG. 5d shows the layout of the flame-exposure experiments,
wherein the arrows indicate the direction of the flames in the
various experiments; and
[0066] FIGS. 6a and 6b show the different ways in which insulating
layers are formed during the expansion of the graphite from a
support element according to the invention as a function of the
orientation of the pressing direction.
DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS
[0067] FIG. 1 shows a first embodiment of the support element
according to the invention for supporting a window frame. The cross
section of the support element 2 has the shape of an angle. An
insulating part 4 with a rectangular cross section can be connected
to the support element 2. The insulating part 4 can also have a
different shape, however, or it can be omitted entirely.
[0068] The support element 2 extends primarily in a longitudinal
direction. The length of a support element 2 in the longitudinal
direction can be freely selected and is preferably between 10 and
150 cm. The support element 2 can be a one-piece unit, or it can
consist of two pieces bonded permanently to each other. In the
embodiment shown, the support element 2 has an L-shaped cross
section. The shape of the support element 2 can also be rectangular
or comprise a beveled surface. The support element 2 is made of a
load-bearing material, which is adapted to bearing the load of the
window fame without itself undergoing deformation.
[0069] It is preferred that the material of the support element 2
have a compressive stress at 10% compression according to DIN EN
826 in the range from 2 to 15 MPa, especially in the range from 4
to 8 MPa. The bulk density of the material should be in the range
from 100 to 1,200 kg/m.sup.3, preferably between 350 and 800
kg/m.sup.3. The thermal conductivity of the rigid foam material
should be in the range from 0.05 to 0.2 W/mK, preferably in the
range from 0.06 to 0.15 W/mK. The material is dimensionally stable
and compressively stable under the load of the window.
[0070] The support element 2 comprises a first side surface 6
extending in the longitudinal direction, which serves to rest
against a wall 8 (FIG. 2). The first side surface 6 is part of a
first web 10 of the support element 2. The support element 2 also
comprises a second longitudinally extending side surface 12, which
is substantially perpendicular to the first side surface 6 and
which serves to support a window frame 34 (FIG. 2). In the
exemplary embodiment shown here, the second side surface 12 is part
of a second web 16 of the support element 2, which is connected to
the first web 10 and projects at an angle from the first web 10. In
the example shown here, the angle is 90.degree.. The first side
surface 6 and the second side surface 12 meet along one edge and
also intersect at the same angle as the two webs 10, 16, i.e.,
therefore at 90.degree. in this case. The second side surface 12
and the third side surface 45 also meet along an edge and intersect
at an angle of 90.degree. in the preferred embodiment
illustrated.
[0071] In the first web 10, one or preferably several through-holes
18 can be provided, which allow the passage of one or more
fastening elements 20 (FIG. 2) such as screws. Each through-hole 18
therefore passes through the first web 10 of the support element 2
from an inner side surface 22, which is opposite the first side
surface 6, to the first side surface 6. As can be derived from FIG.
2, each fastening element 20 serves to fasten the support element 2
to the wall 8.
[0072] It is also possible not to provide any through-holes 18 in
the first web 10 of the support element in advance. Instead, the
through-holes are introduced into the support element 2 by the
installer only after it has arrived at the installation site.
[0073] The insulating part 4 is arranged in the area of the inner
side surface 22 of the first web 10 of the support element 2. It is
preferably made of foam or mineral wool, especially preferably of
hard flexible foam. Such foams are usually self-supporting but
cannot bear any load. Examples of materials of this type include
polystyrene, Styrodur, Styropor, Styrofoam, or Neopur, with bulk
densities of <100 kg/m.sup.3, preferably <50 kg/m.sup.3,
which are known as thermal insulation materials. The compressive
strength of such insulating materials is preferably at most 50% of
the compressive strength of the load-bearing rigid foam used for
the support element 2, usually less than 20% of that strength.
[0074] The insulating part 4 is pivotably connected to an outer
edge area of the first web 10 of the support element 2. It could
also be pivotably connected to an outer edge area of the second web
16 of the support element 2. At the top of FIG. 1, the insulating
part 4 can be seen in its insulating position, in which the
insulating part 4 covers at least most of the inner side surface 22
of the first web 10 of the support element 2; in the present case,
it covers that surface completely. In this position, the insulating
part 4 rests preferably against both the first web 10 and the
second web 16 of the support element 2. It is especially preferred
that the support element 2 and the insulating part 4 fit together
in such a way that they form a rectangular cross section. The
combination of the support element 2 and insulating part 4 is
preferably also transported in this insulating position.
[0075] The lower part of FIG. 1 shows the insulating part 4 as it
is being pivoted; it is on its way into a working position, in
which it exposes at least most of the inner side surface 22 of the
first web 10 of the support element 2. In this working position of
the insulating part 4, the fastening elements 20 can be introduced
into the through-holes 18 without hindrance. If no through-holes 18
are present in the support element 2, the installer has free access
to the first web 10 of the support element 2 when the insulating
part 4 is in this working position and can produce the
through-holes 18 there before he introduces the fastening elements
20 through the through-holes 18 and into the wall 8. The pivot
angle between the working position and the insulating position of
the insulating part 4 is usually between 60.degree. and
120.degree., but there are no limitations. The pivotable connection
between the insulating part 4 and the support element 2 is
preferably achieved by a flexible adhesive strip 24, which is
adhered both to the insulating part 4 and to the support element 2.
In the embodiment shown in FIG. 1, the adhesive strip 24 is
configured as a flat, straight covering over the butt joint between
the support element 2 and the insulating part 4. Many other
arrangements of the adhesive strip 24, however, can also be
envisioned.
[0076] The skilled person can also conceive of many other possible
ways of realizing the pivoting connection between the insulating
part 4 and the support element 2 besides the adhesive strip 24. For
example, the insulating part 4 and the support element 2 could be
connected to each other by a different type of element such as an
elastic element; a small area of the insulating part 4 could also
be laminated directly to the support element 2; or some other
mechanical pivoting connection could be realized between the
insulating part 4 and the support element 2.
[0077] In the embodiment shown in FIG. 1, furthermore, a second
adhesive strip 26 is provided, which connects the edge area of the
second web 16 of the support element 2 to the insulating part 4.
This adhesive strip 26 should be easily detachable at least from
the support element 2, because it must be removed from the support
element 2 before the insulating part 4 can be pivoted into the
working position (FIG. 1, below). The adhesive strip 26 is
preferably reusable, so that, after the support element 2 has been
fastened to the wall 8 and the insulating part 4 has been pivoted
back into the insulating position, it can be reattached to the
support element 2. Instead of the second adhesive strip 26, the
detachable connection between the insulating part 4 and the second
web 16 of the support element 2 can also be realized in some other
way.
[0078] If the pivotable connection is created between the second
web 16 of the support element 2 and the insulating part 4, then
logically the detachable adhesive connection between the insulating
part 4 and support element 2 will be between the insulating part 4
and the first web 10 of the support element 2.
[0079] In principle, however, the pivotable connection between the
insulating part 4 and the support element 2 can also be the only
connection between these two components. The insulating part 4
should then remain in the insulating position without any external
influence; for example, as a result of an appropriate selection of
the size and shape of the support element 2 and of the insulating
part 4, the insulating part can wedge itself detachably between the
inner side of the support element 2 perpendicular to the inner side
surface 22 and the pivoting connection.
[0080] The insulating part 4 can also be configured in such a way
that the surface of the insulating part 4 arranged adjacent to the
inner side surface 22 of the support element 2 leaves enough free
space to accommodate the portions of the fastening elements 20
which may be projecting from the inner side surface 22 (not shown
in the drawing).
[0081] FIG. 2 sketches the installation situation of a support
element 2 according to the invention, wherein the orientation of
the support element 2 represents the situation in which the element
is installed below the window opening. On the other three sides of
the window opening, the support element 2 must be rotated as
appropriate. In addition to the wall 8, to which the support
element 2 is fastened by means of the fastening elements 20, the
illustrated building section 28 usually also comprises an outer
wall 30, which is usually made of a thermally insulating material.
This outer wall is rear-vented, and the support element 2 is
arranged in the intermediate space 32 between the main wall 8 and
the outer wall 30. The outer wall 30 is usually connected to the
main wall 8 by struts, projections, or pins. The window frame 34 is
usually arranged adjacent to the intermediate space 32 and is
supported on the second side surface 12 of the support element 2.
Sealing elements 36 made of PUR foam, for example, can also be
inserted between the window frame 34 and the support element 2.
Sealing elements 38 made of PUR foam, for example, can also be
arranged between the window frame 34 and a projecting part of the
outer wall 30, i.e., a part which projects beyond the height of the
support element 2.
[0082] The strip-shaped support elements are usually arranged
around the entire window opening. It is also possible to install
one or more support elements only underneath the window opening,
because here is where most of the weight of the window is
supported.
[0083] In cases where the window frame 34 is surrounded on all
sides by support elements, the one or more support elements on the
bottom of the window opening are usually connected to the wall 8 by
screws or the like. At this point, but especially on the other
sides of the window opening, it is possible under certain
circumstances that an adhesive bond between the support element 2
and the wall 8 can also be sufficient. The adhesive bond can also
be advantageous when fastening is achieved by means of the
fastening elements 20. The adhesive can preferably serve
simultaneously as a diffusion barrier as well.
[0084] The length of a support element usually corresponds exactly
to the corresponding length or width of the window opening.
Nevertheless, it is also possible to arrange several support
elements in a row along each side of the window opening. The
individual support elements are usually mitered and either butt up
against each other or are preferably attached to each other,
especially by means of an adhesive.
[0085] FIGS. 3a-3h show additional alternatives of the support
elements according to the invention.
[0086] The support element 2 in FIG. 3a corresponds to the support
element of FIG. 1 with the difference that there is no insulating
part here. It is provided intumescent material continuously
throughout. An insulating part is also absent from the other
embodiments described below, but it could just as well be present
in each of them.
[0087] The support element 2 of FIG. 3b corresponds to the support
element of FIG. 3a with the difference that it does not have an
L-shaped cross section; it has instead a wedge shape, with a bevel
on a side facing away from the first side surface 6. The form of
the bevel can be varied in any way desired. It is also conceivable
that the support element 2 could have a rectangular cross
section.
[0088] The support element 2 in FIG. 3c corresponds to the support
element of FIG. 3a with the difference that not the entire support
element is provided with intumescent material but rather only a
layer 47 with intumescent material is provided on the second side
surface 12. The rest of the layer 46 has no intumescent material.
It preferred in this case that the layer 47 be at least 10 mm
thick. If the intumescent material is expandable graphite, it is
preferred that this make up 5-20% of the layer 47. In this
embodiment, it is guaranteed that there will an especially
pronounced upward expansion of the intumescent material in the
direction toward the window frame in the event of a fire.
[0089] The support element 2 of FIG. 3d corresponds to the support
element of FIG. 3c with the difference that the layer 47 with
intumescent material is arranged on the third side surface 45,
i.e., the side facing away from the first side surface 6.
Otherwise, the same parameters as those described for FIG. 3c apply
to the layer 47 here also. In this embodiment, it is guaranteed
that there will be an especially pronounced expansion of the
intumescent material toward the side (toward the right in the
figure) in the direction toward the outer wall.
[0090] The support element 2 of FIG. 3e corresponds to the support
element of FIG. 3c with the difference that an additional layer 47
with intumescent material is arranged on the side facing away from
the second side surface 12.
[0091] The support element 2 of FIG. 3f corresponds to the support
element of FIG. 3c with the difference that the layer 47 with
intumescent material is thinner; it preferably has a thickness of
between 0.25 mm and 10 mm, more preferably between 0.5 mm and 5 mm,
even more preferably between 1 mm and 3 mm. If the intumescent
material is expandable graphite, it preferably makes up 20-70%,
more preferably 30-60% of the layer 47.
[0092] The strip-shaped layer 47 with intumescent material in FIG.
3f is fabric-like, film-like, or paper-like. The layer 47 in the
original state is preferably in the form of a roll of material,
which is unwound and adhered to the layer 46. In the embodiment
according to FIG. 3f, it is guaranteed that, in the event of a
fire, there will be an especially pronounced upward expansion of
the intumescent material in the direction toward the window
frame.
[0093] The support element 2 of FIG. 3g corresponds to the support
element of FIG. 3f with the difference that the layer 47 with
intumescent material is arranged on the third side surface 45,
i.e., the side surface facing away from the first side surface 6.
Otherwise, the same parameters as those described for FIG. 3f apply
to the layer 47 also. In this embodiment, it is guaranteed that, in
the event of a fire, there will be an especially pronounced
expansion of the intumescent material toward the side (toward the
right in the figure) in the direction of the outer wall.
[0094] The support element 2 of FIG. 3h corresponds to the support
element of FIG. 3f with the difference that the layer 47 with
intumescent material covers only part of the second side surface
12.
[0095] The layer 47 of the embodiment of FIG. 3d can also be
combined with the layers 47 of the embodiment of FIG. 3c or 3e. The
thin layer 47 of the embodiment of FIG. 3g can also be combined
with the thin layer 47 of the embodiment of FIG. 3f or 3h. In
addition, various thin layers 47 with various thicknesses of the
layer 47 can be combined. For example, the thin layer 47 of FIG. 3g
can be combined with the thick layer 47 of FIG. 3c.
[0096] In principle, all of the side surfaces or any desired
selection of side surfaces can be completely or partially covered
by a layer 47 with intumescent material.
[0097] The geometries of the support element 2 described on the
basis of FIG. 3b can also be used in all of these embodiments.
[0098] In all of the previously described variants, one or more
layers 47 can also extend over only a part of the associated side
surface.
PRODUCTION EXAMPLES
Example 1A: Support Element with Waterglass
[0099] Inert sodium or potassium silicate (10-20%) is mixed to form
a homogeneous mass with the base material, e.g., a rigid PUR foam
or a rigid PUR/PIR foam, and optionally with one or more additives
such as a curing agent. The mixture is pressed in a mold and cured
by heat. Panels can be cut and processed into strip-shaped support
elements.
Example 1B: Support Element with Expandable Graphite
[0100] Rigid PUR and/or PIR foam which originates from production
residues and/or recycled material, e.g., old insulating panels, and
which has been ground to a maximum particle size of approximately 5
mm, preferably of approximately 1 mm, is mixed with 5-10%,
preferably 7.5%, of expandable graphite (average particle size,
approximately 1 mm) and binder material, e.g., in liquid form, in a
ratio of 1:5, calculated on the basis of the weight of the ground
rigid foam. The mixture is introduced into a panel mold and treated
by heat and pressure in a pressing direction P perpendicular to the
surface of the panels, so that a rigid foam material with a bulk
density of approximately 550 kg/m.sup.3 is obtained. The thickness
of the panels is preferably 2-7 cm.
[0101] Alternatively, comminuted rigid foam pieces, expandable
graphite flakes, and binder material can be introduced layer by
layer in alternation (e.g., by interspersing) and then pressed.
[0102] Cured panels resulting from the pressing operation are cut
into strip-shaped parts, and L-shaped support elements 2 according
to FIG. 3a are produced by bonding a wider and a narrower element
together, wherein, for both elements, the pressing direction P is
preferably perpendicular to the second surface 12, which is
intended to rest against the window frame 24 (see FIG. 1). The
bonding is achieved by the use of an adhesive and/or by mechanical
fastening with nails, screws, or metal clamps.
Example 1C: Support Element with an Expandable Graphite-Containing
Layer
[0103] In the alternative embodiment shown in FIG. 3c, the upper
layer 47 of the produced panel (i.e., a surface perpendicular to
the pressing direction P) has a thickness of at least 10 mm,
preferably of 15 mm, and has been combined with expandable
graphite, wherein the remainder of the support element has not been
combined with expandable graphite.
[0104] The strip-shaped support elements are produced as described
in Example 1B.
Fire Tests
[0105] According to the test criteria of DIN 1366-5, support
elements 2 of rigid PUR/PIR foam with expandable graphite, produced
according to Example 1B with a thickness of 30 mm or 50 mm, were
exposed to flames at 180.degree. C. (see test layout in FIG. 5d),
during which procedure the increase in temperature was measured on
the opposite side after 5, 15, and 25 minutes in comparison to
corresponding rigid foam without expandable graphite.
[0106] On the side facing away from the flames, the temperatures
were measured directly on the material after 5, 15, and 25 minutes
for experimental applications on a ceiling (Tables 1-4) and a wall
(Tables 5-6). The measured temperature increases (in degrees
Kelvin; starting temperature, 23.degree. C.) are reproduced in the
following tables (Tables 1, 3, 5: measurement on surface of the
elements; Tables 2, 4, 6: measurement at the butt joint).
Ceiling
TABLE-US-00001 [0107] TABLE 1 30 mm, surface. test site material
without expandable graphite material with expandable graphite 3.29
4.03 4.10 4.14 3.01 3.07 3.08 3.14 5 min 1 0 1 0 1 1 1 7 15 min 15
23 26 2 22 21 24 29 25 min 52 52 52 20 43 43 48 53
TABLE-US-00002 TABLE 2 30 mm, butt joint. no graphite with graphite
test site 3.32 4.07 3.04 3.11 5 min 4 2 2 10 15 min 30 32 17 35 25
min 117 158 45 56
TABLE-US-00003 TABLE 3 50 mm, surface. test site material without
expandable graphite material with expandable graphite 4.11 4.17
4.18 4.24 3.15 3.21 3.22 3.28 5 min 0 0 0 0 0 0 3 3 15 min 1 3 2 2
2 3 4 4 25 min 11 11 17 11 9 9 12 12
TABLE-US-00004 TABLE 4 50 mm, butt joint. no graphite with graphite
test site 4.14 4.21 3.18 3.25 5 min 1 2 0 3 15 min 2 4 3 4 25 min
20 18 12 12
Wall:
TABLE-US-00005 [0108] TABLE 5 30 mm, surface. test site material
without expandable graphite material with expandable graphite 1.15
1.21 1.22 1.28 1.29 7.07 7.08 7.14 5 min 8 0 5 1 8 1 8 5 15 min 19
22 30 20 33 25 30 30 25 min 57 50 52 49 57 44 49 50
TABLE-US-00006 TABLE 6 30 mm, butt joint. no graphite with graphite
test site 1.18 1.25 1.32 7.11 5 min 2 1 2 3 15 min 30 22 30 25 25
min 80 67 50 45
[0109] Through the use of expandable graphite in the support
elements 2 used both on ceilings and walls, the increase in
temperature, especially at the butt joints, is considerably
reduced. Thus, in the case of the rigid foam on the ceiling without
expandable graphite, the temperature in the joint increased by, on
average, 137.5.degree. C. after 25 minutes; in the case of material
with expandable graphite, it increased by only 50.5.degree. C. on
average. On the wall, the temperature of the rigid foam without
expandable graphite increased in the joint by 73.5.degree. C. on
average; and in the case of the material with expandable graphite,
it increased by only 47.5.degree. C. on average. The increase in
temperature, especially at the joints, was therefore significantly
reduced by the use of support elements with expandable
graphite.
[0110] FIGS. 4a and 4b show support elements with homogeneously
distributed expandable graphite with an original thickness of 3 cm
after exposure to flame on one side for 30 minutes (at the top in
the figure). A graphite layer approximately 8 cm thick developed
from 1 cm of material used.
[0111] FIGS. 5a-5c show top views of the flame-exposed side of
support elements with homogeneously distributed expandable graphite
with an expanded graphite layer on the flame-exposed side. In FIGS.
5a-5c, the arrows indicate the butt joints between adjacent
components. FIG. 5d shows the layout of the flame exposure
experiment. In FIG. 5d, the arrows indicate the direction of the
flames in the various experiments. Depending on the arrangement
(compare FIG. 5d, schematic diagram in the cross-sectional plane),
the expanded graphite layer projects clearly beyond the plane of
the concrete elements between the support elements, whereas the
element, prior to exposure to flame, is on the same level with them
(see especially FIG. 5b).
[0112] On the left, FIG. 6a shows part of a 30-mm-thick support
element partially sawn through after 30 minutes of exposure to
flame; the pressing direction P, indicated by the arrow, extends
horizontally. The expansion in the direction of the pressing
direction P is approximately twice as great (about 8 cm) as the
expansion on the side perpendicular to the pressing direction, here
the flame-exposed side on the right (approximately 4 cm). FIG. 6b
shows the test piece after rotation by 90.degree.. It was thus
determined that the expansion of the intumescent material on a
surface perpendicular to the pressing direction P leads to greater
expansion in the event of a fire than on a surface parallel to the
pressing direction P.
* * * * *