MINERAL HEAT-INSULATION MATERIAL

MATERIAU MINERAL D'ISOLATION THERMIQUE

English Abstract

The method for applying a heat insulation layer to an area is characterized in
that
alpha-hemihydrate or beta-gypsum or lime-alpha-hemihydrate or a mixture
thereof is
mixed as hydraulic binder with a pore former consisting of aluminum powder,
mixed
with ground limestone, and citric acid with addition of water and is cast in
liquid or pasty
form onto the area. The mixture has a pH of 11.8 or more. The constituents are

preferably mixed on site, namely in such a consistency that the mixture is
self-leveling.
Placement on the laying site can e.g. be carried out by means of a floor
screed pump.
The material expands to the desired total thickness, yielding a homogeneous
insulation
layer of uniform thickness and quality and of high strength that will reach
its high final
strength after about 24 hours. The material can also be applied in a pasty
consistency
to a wall.

French Abstract

La méthode dapplication dune couche disolation thermique à une aire est caractérisée en ce quun alpha-hémihydrate, un bêta-gypse ou un lime-alpha-hémihydrate ou un mélange de ceux-ci est mélangé comme un liant hydraulique avec un agent porogène constitué daluminium en poudre, mélangé à de la chaux broyée, et de lacide citrique avec ajout deau, pour ensuite être coulé sous forme dun liquide ou dune pâte sur laire. Le mélange a un pH de 11,8 ou plus. Les constituants sont de préférence mélangés sur place, à une consistance telle que le mélange sautonivelle. Le placement sur le site de couchage peut, par exemple, être réalisé au moins dune pompe à chapes. Le matériau sétend à lépaisseur totale souhaitée, produisant une couche disolation homogène dune épaisseur uniforme et dune qualité et dune résistance élevée, dont la résistance finale élevée sera atteinte après environ 24 heures. Le matériau peut également être appliqué à la consistance dune pâte sur un mur.

Claims

6

Claims

1. A method of applying a heat insulation layer to a surface, comprising:
providing a mixture containing:
a hydraulic bonding agent comprising 80-90 wt % of total solid
materials of the mixture, the hydraulic bonding agent containing
alpha-hemihydrate, beta-gypsum, or a mixture of alpha-hemihydrate and
beta gypsum,
an aluminum powder-limestone flour mixture comprising 5-14.95 wt
% of the total solid materials, the aluminum powder-limestone flour
mixture having a ratio of about 90% limestone flour to about 10%
aluminum powder,
lime comprising 0.5-5.0 wt % of the total solid materials,
citric acid comprising about 0.05 wt % of the total solid materials,
and
water,
wherein the mixture has a pH of 11.8 or more; and
applying the mixture in liquid or paste form onto the surface, wherein a
water/bonding agent factor is about 0.35-0.65%.
2. The method according to claim 1, wherein the surface is a floor surface.
3. The method according to claim 1, wherein the surface is a wall surface
and that
the mixture is of a pasty consistency.
4. The method according to claim 1 or 2, wherein the providing comprises
mixing
the mixture at a place of installation.
5. The method according to claim 1 or 2, wherein the provided mixture is of
such a
consistency that it is self-leveling.


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6. The method according to any one of claims 1-5, wherein the applied
mixture
introduces a heat insulation layer to the surface, and wherein the introduced
heat
insulation layer hardens to reach its final strength after about 24 hours.
7. The method according to claim 6, wherein the final strength in the
applied
mixture is maintained after hardening.
8. The method according to any one of claims 1-7, wherein the mixture is
100%
recyclable.
9. The method according to any one of claims 1-8, wherein the heat
insulation layer
includes a highly uniform pore structure; and wherein the heat insulation
layer is
open to vapor diffusion.
10. The method according to any one of claims 1-9, wherein after applying
the
mixture, the aluminum powder reacts to form aluminate and hydrogen, wherein
heat is developed; and wherein the heat development creates water vapor, the
water vapor loosening a solid structure of the mixture and leaving pores in
the
solid structure, the pores being filled with air.
11. A method of providing a heat insulation layer for a surface,
comprising:
mixing a bonding agent, a pore former, lime, and citric acid with an
addition of water to provide a mixture having a pH of 11.8 or more, the
bonding
agent comprising 80-90 wt. % of total solid materials, the pore former
comprising
5-14.95 wt % of the total solid materials, the lime comprising 0.5-5.0 wt % of
the
total solid materials, and the citric acid comprising about 0.05 wt % of the
total
solid materials; and
applying the mixture in liquid or paste form onto the surface to provide the
heat insulation layer, wherein a water/bonding agent factor is about 0.35-
0.65%;
wherein the hydraulic bonding agent contains alpha-hemihydrate,


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beta-gypsum, or a mixture of alpha-hemihydrate and beta gypsum; and
wherein the pore former comprises blended aluminum powder and
limestone flour having a ratio of about 90% limestone flour to about 10%
aluminum powder.
12. The method according to claim 11, wherein said mixing takes place at a
place of
use.
13. The method according to claim 11 or 12, further comprising:
allowing the heat insulation layer to harden, wherein the heat insulation
layer hardens to its final strength after about 24 hours.
14. The method according to any one of claims 11-13, wherein the surface is
a floor
surface.
15. The method according to any one of claims 11-13, wherein the surface is
a wall
surface.

Description

CA 02696553 2014-11-20
1
Mineral heat-insulation material
The present invention relates to a mineral heat-insulation material which is
e.g.
usable as an interior wall insulation, roof insulation, floor insulation,
façade insulation,
as an insulation for passages leading, for example, to basement garages, and
for filling
cavities with heat-insulating effect, and to the formation of a load-bearing
heat
insulation underneath concrete constructions in building and civil
engineering.
It is known that a mixture is prepared from calcium silicate hydrates, lime,
sand,
cement, water and pore formers, the mixture being cast into large blocks,
heated to
about 190 C. and cut into stone slabs after cooling by means of autoclaves.
This
requires a considerable amount of energy and also has the drawback that with
many
applications it is not possible to cover the whole area prone to heat loss by
laying
heat-insulating panels because some parts of the area are often concealed, for
instance, by vent channels or cable/pipes, etc. In the case of a reinforced
concrete floor
it is normally only about 85% of the area that is adapted to be covered by
heat
insulating panels.
EP 0 490 160 Al discloses a process for manufacturing gypsum building
materials, in which alpha-hemihydrate with a Blaine specific surface area is
mixed with
beta-hemihydrate and a prefabricated surfactant foam is added to said mixture,
which
foam is prepared by means of a foam gun at a specific water/surfactant/air
ratio and
with a defined foaming length, which is meant to yield a substantially uniform
pore size.
The suspension is then subjected to a forming process, particularly in the
form of wall
panels that are then introduced into an autoclave where they are exposed to a
saturated vapor treatment and to a temperature of up to 200 C.
The present invention may provide a better solution for these problems.

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2
Broadly stated, the invention provides a method of applying a heat insulation
layer to a surface. The method includes providing a mixture containing:
a hydraulic bonding agent comprising 80-90 wt % of total solid materials of
the
mixture, the hydraulic bonding agent containing alpha-hemihydrate, beta-
gypsum, or a
mixture of alpha-hemihydrate and beta gypsum,
an aluminum powder-limestone flour mixture comprising 5-14.95 wt % of the
total
solid materials, the aluminum powder-limestone flour mixture having a ratio of
about
90% limestone flour to about 10% aluminum powder,
lime comprising 0.5-5.0 wt (3/0 of the total solid materials,
citric acid comprising about 0.05 wt (3/0 of the total solid materials, and
water, wherein the mixture has a pH of 11.8 or more, and
applying the mixture in liquid or paste form onto the surface, wherein a
water/bonding agent factor is about 0.35-0.65%.
The invention also broadly provides a method of providing a heat insulation
layer
for a surface. The method includes:
mixing a bonding agent, a pore former, lime, and citric acid with an addition
of
water to provide a mixture having a pH of 11.8 or more, the bonding agent
comprising
80-90 wt. % of total solid materials, the pore former comprising 5-14.95 wt %
of the total
solid materials, the lime comprising 0.5-5.0 wt % of the total solid
materials, and the
citric acid comprising about 0.05 wt % of the total solid materials; and
applying the mixture in liquid or paste form onto the surface to provide the
heat
insulation layer, wherein a water/bonding agent factor is about 0.35-0.65%;
wherein the hydraulic bonding agent contains alpha-hemihydrate, beta-gypsum,
or a mixture of alpha-hemihydrate and beta gypsum; and
wherein the pore former comprises blended aluminum powder and limestone
flour having a ratio of about 90% limestone flour to about 10% aluminum
powder.
According to the invention the heat insulation layer contains the constituents
alpha-hemihydrate or beta-gypsum or lime-alpha-hemihydrate or a mixture of two
or

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three of said constituents as hydraulic binder, pore formers of aluminum
powder and
ground limestone, which are blended with one another, lime and a retarding
agent such
as citric acid. Like the other constituents, the citric acid is added in a
ground state.
The lime is added in such an amount that according to the invention the
finished
mixture has a pH of 11.8 or more. Without lime the pH would normally be 8 to
10. Due
to the alkaline environment the aluminum powder reacts to form aluminate and
hydrogen, which loosens the binder mass, and the resulting heat development
creates
water vapor which will then loosen the solid structure and leave the pores.
The pore
structure is very uniform. The heat insulation material is thus open to vapor
diffusion.
The citric acid in combination with the other constituents has the advantage
that
the compressive strength is not decreasing, but always remains the same. By
contrast,
in conventional mineral heat-insulation materials the compressive strength is
decreasing by about 5-8%. The compressive strength is maintained in the
mixture
according to the invention.
The constituents of the mixture are preferably composed as follows:
Binder 80-90% by wt. of the total solids content
Aluminum-limestone powder in
the mixture of 90% limestone
powder + 10% aluminum 5-14.95% by wt. of the total solids
content
Lime 0.5-5.0% by wt. of the total solids
content
Citric acid about 0.05% by wt. of the total solids content
The water/binder factor is preferably 0.35-0.65%.
The constituents of the mineral heat-insulation materials are preferably mixed
on
site with addition of water and are cast in liquid (or paste-like) form onto
the substrate.

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The mixture is preferably of such a consistency that it is self-leveling.
The heat-insulation material mixture is preferably cast at a thickness of
between
1 cm and 2 cm onto the substrate, in which process the introduced mixture does
not
require any considerable leveling and screeding work. Placement on the laying
site can
e.g. be carried out with floor screed pumps. The material will then expand at
the
above-indicated thickness of 2 cm of the base material to a total thickness of
about 51
mm, thereby yielding a homogeneous insulation layer of equal thickness and
quality
and of high strength.
The cast insulation material will be hard enough to be walked on after about
60
min and will reach its high final strength after about 24 hours.
The energy input for forming the thermal insulation layer is only about 1% of
the
energy input required e.g. by porous concrete stones.
The chemical process in the heat insulation material according to the
invention is
as follows: the aluminum expands at a pH of 11.8 or more and generates pores
while
forming hydrogen, the pores being present in the structure in a stable state
after drying.
These pores are filled with air so that a highly efficiently heat insulation
material is
obtained because air is one of the poorest heat conductors. The finished
insulation
layer does not evaporate and is non-combustible (Fuel Class Al).
Moreover, the heat insulation material according to the invention is 100%
recyclable. If the material has to be removed again, it can be remixed with
water after
renewed grinding with an amount of hydraulic binder and with addition of pore
formers,
resulting in the same product again.
The mineral insulating material according to the invention can be cast in the
retrofitting of existing buildings onto wooden floors that statically require
a small weight.

CA 02696553 2014-11-20
It is also highly suited as impact sound insulation material e.g. in the case
of joist
ceilings having a low weight of their own. As a liquid, self-leveling
insulation, each spot
of the floor area to be insulated can be reached. The invention also provides
for a fast
and easy insulation of a wall area. While a wall is being insulated, one can
proceed
5 section wise from the bottom to the top with a pasty base material for
instance in strips
of a height of 1.5 m.
It is also possible to prefabricate panels of any desired dimension as façade
insulation panels for direct adhesive bonding by means of a commercially
available
adhesive. This façade insulation has the advantage that a good insulation is
achieved.
The insulating system permits the passage of solar energy into the massive
building
material and is simultaneously open to vapor diffusion for the possible
transportation of
moisture. This prevents the formation of mold within the building. Thus the
temperature
equalization between indoor air and outdoor temperature is also called
instationary
U-value, which ensures a balanced room climate while guaranteeing good heat
insulation. Contrary to the Energy Saving Directive, it is possible with this
system to
include the solar gains in the loss and profit calculation.
It should be noted that the invention is not limited to the above-described
embodiments. Rather, all of the disclosed features can be combined
individually with
one another in any desired way.