Title of Invention

HYDRAULIC BINDER

Abstract In a hydraulic binder containing slags, aluminium-silicates and calcium sulphate, slag, in particular furnace slag, in amounts below 50% (w/w) as well as aluminium-silicates different from furnace slag, as for example flue-ash and natural aluminium-silicates, as for example basalt or andesite, in amounts of 5 to 75% (w/w) respectively related to the entire blend with the requirement that the sum of slag and aluminium- silicates is between 82 and 95,9% (w/w) and as one of the activators CaSO4 in amounts between 4 and 15% (w/w) as essential components are present. Additionally alkali activators, in particular alkali hydroxides and/or —carbonates of Na and/or K in amounts from 0,1 to 3% (w/w) are deployed.
Full Text Hydraulic binder
The invention relates to a hydraulic binder containing slags,
aluminium-silicates and calcium-sulphate.
The composition and production of super sulphated
metallurgical cements is based on the addition of calcium-
sulphate to the cement. According to the international
organisation for standardisation (ISO) super sulphated cement
is defined as a blend of at least 75% (w/w) hackled,
granulated furnace slag, large additives of calcium-sulphate
(> 5% (w/w) SO,) and at most 5% (w/w) slacked lime, portland-
cement clinker or Portland-cement.
For the production of super sulphated cement the granulated
slag according to the German norm has to contain at least 13%
(w/w) Al2O3 and has to correspond to the formula (CaO + MgO +
Al2O3)/SiO2 > 1,6. According to Keil an amount of 15 to 20%
alumina slag with a minimal modulus of (CaO + CaS + 0,5 MgO +
Al2O3)/(SiO2 + MnO) > 1,8 is preferred. According to Blondiau
the CaO/Si02 ratio has to be between 1,45 and 1,54 and the
Al2Oa/SiO2 ratio has to be between 1,8 and 1,9.
Lime, clinker or cement are added in order to increase the ph-
value in the cement-paste and to enhance the solubility of
alumina soil in the liquid phase during the hydratisation of
the cement. The hardening of super sulphated metallurgical
cement can take place without chemical additives or a specific
formation treatment.
The US 5 626 665 discloses a mixed puzzolana for use with
Portland-cement for the production of a cement like system.
The mixed puzzolana contains burned clay and at least one
component chosen from the group consisting of at about 2% to
at about 30% hard plaster, at about 0% to at about 25%
hydrated kiln dust, at about 0% to at about 20% hydrated lime,
at about 0% to at about 20% hydrated lime kiln dust, at about
0% to at about 50% flue-ash and at about 0% to at about 5%
organic plastif icator. The burned lime is present in
sufficient amounts in order to yield a mixed puzzolana with a
final total weight of 1001. The mixed puzzolana is mixed with
Portland-cement in a weight-ratio of at about 1:20 to at about
1:1, preferably at about 1:2 to at about 1:3.
In normal Portland-cements and metallurgical cements, in which
the hydratisation takes place in the liquid phase free of
solubilized alumina, the content of calcium-sulphate is
restricted to a minor percentage in order to avoid a potential
inner decay due to the formation of calcium-sulfo-aluminate
(candlot bacilli) as a consequence of the non-solubilized
alumina. In these cements the main influence of calcium-
sulphate consists in the retarding action, which it excerpts
on the setting time. The basicity of the hydrated calcium
aluminates as well as the insolubility of the alumina
contained in the aluminates depends on the lime concentration
in the liquid phase of the cement and this independently from
whether the hydrated calcium aluminates in the hardened cement
are present in the crystalline form or in the amorphous form.
The lime concentration in the liquid phase determines the kind
of influence of the calcium-sulphate on the setting time of
the cement and the maximal calcium-sulphate amount, which the
cement can contain without resulting into inner decay to
retarded formation of ettringite.
In super sulphated metallurgical cements the lime
concentration in the liquid phase is below the limit of
unsolubility of the alumina. Larger additions of calcium-
sulphate for the activation of reactions of furnace slag
determine the formation of tricalcium-sulfo-aluminate with
higher hydraulic activity on the basis of the solubilized lime
and the solubilized alumina without resulting in potential
decay. The addition of calcium-sulphate to granulated furnace
slag does not create expansion-cement but acts as accelerating
agent in the formation of hydrated compounds. In super
sulphated cement larger portions of calcium-sulphate are not
to be considered as troublesome. The tricalcium-sulfo-
aluminate, in which they result, in fact rather contribute to
an increase of the hydraulic activity instead of causing
decay, as it is the case for Portland-cement and normal
metallurgical cement.
The initial setting and hardening of super sulphated cement
goes along with the formation of the high sulphate form of
calcium-sulfo-aluminate from the slag components and the added
calcium-sulphate. The addition of Portland-cement to cement is
required for the adjustment of the adequate alkalinity in
order to allow for the formation of ettringite. The most
important products of hydratisation are the mono- and
trisulfo-aluminate-tobermorite-like phase and alumina.
Super sulphated cement in the course of the hydratisation
binds to more water than Portland-cement. It fulfils all
requirements of the norm of cement as to the grinding
fineness. It is considered as cement with low calorific value.
As any portland- or metallurgical cement it can be used in
form of concrete, setting mortar or groove mortar. The
conditions to be considered for the use of super sulphated
cement are identical with those that are decisive for the
mixing and the application of other cements.
For the improvement of alumino silicate-binders it has already
been suggested to activate them with alkali and in particular
soda-brine or potassium hydroxide brine.
Alkali activated alumino silicate-binders (AAAS) are cement-
like materials which are formed by reaction of fine silica-
und alumina solids with an alkali- or alkali-salt solution for
the production of gels and crystalline compounds. The
technology of alkali activation was originally developed by
Purdon from 1930 to 1940 who discovered that the addition of
alkali to slag yields a rapidly hardening binder.
ln contrary to super sulphated cement a large variety of materials (natural or
burned lime, slag, flue-ash, belite alluvia, milled stone etc.) can be used as a
source for alumino silicate-materials. Different alkali solutions can be used for the
production of hardening reactions (alkali hydroxide, silicate, sulphate and
carbonate etc.). That means that the sources for AAAS-binders are practically
unlimited.
During the alkali activation a high concentration of OH-ions acts on the mixture of
the alumino silicates. While in Portland- or super sulphated cement-paste a pH >
12 is generated due to the solubility of calcium hydroxide, the pH- value in the
AAAS-system is beyond 13.5. The amount of alkali, which is in general between
2 to 25% (w/w) alkali (> 3% Na2O), depends on the alkalinity of the alumino
silicates.
The reactivity of an AAAS-binder depends on its chemical and mineral
composition, the degree of vitrification and the grinding fineness. In general,
AAAS-binders can begin to set within 15 min and on the long run offer a quick
hardening and a considerable increase in strength. The setting reaction and the
process of hardening are still not completely understood. They go along with the
initial leaching of alkali and the formation of slight crystalline calcium
hydrosilicates of the tobermorite-group. Calcium-alumino silicates begin to
crystallize to form zeolite-like products and consequently alkali-zeolite.
The strength values in the AAAS-system are contributed to the intense
crystallization contact between zeolites and calcium hydrosilicates. The hydraulic
activity is improved by an increase of the alkali doses. The relation between the
hydraulic activity and the amount of alkali as well as the presence of zeolite in the
hydrated product has revealed that alkali not only act as simple catalyst but also
participate in reactions in the same way as lime and hard plaster and feature
a relatively high strength due to a considerable influence of
cations.
In numerous studies concerning the activity of silico
aluminate materials with alkali and their salts have been
reported.
In the WO 00/00447 a super sulphated hydraulic binder has
already been suggested in which calcium-sulphate in amounts of
more than 5% (w/w) has been deployed. Along with aluminium-
silicates under which in the definition of the WO 00/00447
also furnace slag has been subsumed, it was essential in the
prior embodiment of the hydraulic binder that the cement kiln
dust was added in amounts from 3 to 10% (w/w) as the
activator. Additionally it was essential in this prior
embodiment that at least 35% (w/w) furnace slag were deployed
in order to be able to safeguard adequate strength values at
an early stage. Over all, however, a relatively low strength
at an early stage resulted with decreasing content of furnace
slag, whereby at the same time due to the addition of cement
kiln dust the water/cement factor rose and the hazard of
shrinking and hence formation of cracks increased.
The invention thus aims to replace higher amounts of furnace
slag by aluminium-silicates different from furnace slag as for
example flue-ash and at the same time to achieve an improved
strength at an early stage and an improved shrinking
performance with a reduced tendency to the formation of
cracks.
To solve this object the hydraulic binder according to the
present invention generally consists in that slag and in
particular furnace slag in amounts from 7 to 50% (w/w) as well
as aluminium-silicates different from furnace slag, preferably
flu-ash and natural aluminium-silicates, preferably basalt or
andesite, in amounts from 5 to 75% (w/w) with the requirement
that the sum of slag and aluminium-silicates is between 82 and
95, 9% (w/w) and CaSO4 in amounts between 4 and 15% (w/w) are
present and that additionally alkali activators and in
particular alkali hydroxide and/or -carbonate of Na and/or K
in amounts of 0,1 to 3 % (w/w) are deployed. According to the
invention the addition of cement kiln dust can be totally
abandoned which is why the water/cement factor can be reduced
and the risk of the formation of cracks can be minimized. A
respectively smaller addition of an alkali activator leads to
acutely favourable strength values at an early stage, whereby
in the case of the use of cement kiln dust as alkali activator
as well as in the case of other alkali activators the amount
here is explicity confined to values under 3% (w/w) in order
not to deteriorate the positive shrinking performance.
As setting accelerator advantageously also Portland-cement
clinker in amounts between 0,1 and 5% (w/w) can be deployed.
Over all it is feasible with the hydraulic binder according to
the invention to essentially abandon CaO, so that the
production of the binder becomes more environment-friendly
because of the CO, emission being reduced by the abandonment
of the burning of limestone. In a particularly advantageous
manner, however, the mixture can contain limestone and/or
sands or quartzes with the requirement that the Al2O3-content
of the mixture is s 5% (w/w).
Super liquefier or plastification agents respectively can be
added for the improvement of the processability and/or for the
reduction of the water/cement ratio in a conventional manner
whereby preferably plastification agent and/or super liquefier
is added to the binder in amounts from 0,1 to 1% (w/w) related
to the dry substance for the reduction of the water/cement
ratio.
Over all, by the feasibility to replace further furnace slag
by aluminium-silicates different from furnace slag without
abandonment of strength at an early stage, the possibility is
opened up to improve the shrinking performance at an early-
stage and to reduce the water demand. The consequence is a
reduced permeability and higher fatigue endurance.
In the following the invention will be explained by means of
exemplary embodiments as listed in table 1. Table 1 at the
same time shows also the respective strength values (CS) after
one day, after two days and after 28 days.
In fig. 1 the shrinking performance of the binder according to
the invention with at least partial replacement of the furnace
slag by flu-ash can be seen and the resulting improvement is
pointed out.
WE CLAIM:
1. Hydraulic binder containing slags, aluminium-silicates and calcium
sulphate, characterized in that slag, in particular furnace slag, in amounts
from 7 to 50% (w/w) as well as aluminosilicates different from furnace
slag, namely natural aluminosilicates, preferably basalt, andesite, or fly
ash, in amounts of 5 to 75% (w/w) with the requirement that the sum of
slag and aluminium-silicates is between 82 and 95.9% (w/w) and CaSO4
in amounts between 4 and 15% (w/w) is present and that in addition alkali
activators, in particular alkali hydroxides and/or -carbonates of Na and/or
K in amounts from 0.1 to 3% (w/w) are deployed.
2. Hydraulic binder as claimed in claim 1, wherein furnace slag in amounts
between 20 and 35% (w/w) are deployed.
3. Hydraulic binder as claimed in claim 1 or 2, wherein the mixture
additionally contains limestone and/or quartzes with the requirement that
the Al2O3 contents of the mixture is = 5% (w/w).
4. Hydraulic binder as claimed in claims 1, 2 or 3, wherein plastification
agent and/or super liquefier in amounts from 0.1 to 1% (w/w) related to the
dry substance are added.
5. Hydraulic binder as claimed in any one of claims 1 to 4, wherein portland-
cement clinker in amounts between 0.1 and 5% (w/w) as setting
accelerator is deployed.

In a hydraulic binder containing slags, aluminium-silicates
and calcium sulphate, slag, in particular furnace slag, in
amounts below 50% (w/w) as well as aluminium-silicates different
from furnace slag, as for example flue-ash and natural
aluminium-silicates, as for example basalt or andesite, in
amounts of 5 to 75% (w/w) respectively related to the entire
blend with the requirement that the sum of slag and aluminium-
silicates is between 82 and 95,9% (w/w) and as one of the
activators CaSO4 in amounts between 4 and 15% (w/w) as essential
components are present. Additionally alkali activators, in
particular alkali hydroxides and/or —carbonates of Na and/or K
in amounts from 0,1 to 3% (w/w) are deployed.

Documents:

03092-kolnp-2006-abstract.pdf

03092-kolnp-2006-claims.pdf

03092-kolnp-2006-correspondence others-1.1.pdf

03092-kolnp-2006-correspondence others.pdf

03092-kolnp-2006-correspondence-1.2.pdf

03092-kolnp-2006-description(complete).pdf

03092-kolnp-2006-form-18.pdf

03092-kolnp-2006-form-26.pdf

03092-kolnp-2006-form1.pdf

03092-kolnp-2006-form2.pdf

03092-kolnp-2006-form3.pdf

03092-kolnp-2006-form5.pdf

03092-kolnp-2006-international publication.pdf

03092-kolnp-2006-international search authority report.pdf

03092-kolnp-2006-pct form.pdf

03092-kolnp-2006-priority document.pdf

3092-KOLNP-2006-(03-01-2012)-FORM-27.pdf

3092-KOLNP-2006-(29-08-2012)-FORM-27.pdf

3092-KOLNP-2006-ASSIGNMENT.pdf

3092-KOLNP-2006-CORRESPONDENCE 1.1.pdf

3092-kolnp-2006-correspondence.pdf

3092-kolnp-2006-examination report.pdf

3092-KOLNP-2006-FORM 1 1.1.pdf

3092-kolnp-2006-form 18.pdf

3092-KOLNP-2006-FORM 2 1.1.pdf

3092-kolnp-2006-form 26.pdf

3092-KOLNP-2006-FORM 3 1.1.pdf

3092-kolnp-2006-form 3.pdf

3092-KOLNP-2006-FORM 5 1.1.pdf

3092-kolnp-2006-form 5.pdf

3092-KOLNP-2006-FORM 6.pdf

3092-KOLNP-2006-GPA 1.1.pdf

3092-kolnp-2006-gpa.pdf

3092-kolnp-2006-granted-abstract.pdf

3092-kolnp-2006-granted-claims.pdf

3092-kolnp-2006-granted-description (complete).pdf

3092-kolnp-2006-granted-form 1.pdf

3092-kolnp-2006-granted-form 2.pdf

3092-kolnp-2006-granted-specification.pdf

3092-kolnp-2006-others.pdf

3092-kolnp-2006-reply to examination report.pdf


Patent Number 247810
Indian Patent Application Number 3092/KOLNP/2006
PG Journal Number 21/2011
Publication Date 27-May-2011
Grant Date 24-May-2011
Date of Filing 25-Oct-2006
Name of Patentee HOLCIM TECHNOLOGY LTD
Applicant Address ZURCHERSTRASSE 156, CH-8645 JONA
Inventors:
# Inventor's Name Inventor's Address
1 GEBAUER, JURAJ HUBEIWEG 2, CH-5106 VEITHEIM
2 KO,SUZ-CHUNG UNTERER HALDENWEG 21A, CH-5600 LENZBURG
3 ADLER, MICHAEL STEINISWEG 29, CH-3034 MURZELEN
PCT International Classification Number C04B7/21
PCT International Application Number PCT/IB2005/000877
PCT International Filing date 2005-04-05
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 A 600/2004 2004-04-05 Austria