HYDRAULIC BINDER
The present invention relates to a hydraulic binder comprising a low quantity of
Portland clinker and several different mineral additions, a hydraulic composition
comprising said hydraulic binder, a shaped object comprising said hydraulic composition
and a process to increase the compressive mechanical strengths of a hydraulic
composition comprising a low quantity of Portland clinker.
The main problem for hydraulic compositions comprising a mineral addition which
partially replaces the Portland clinker is the decrease of compressive mechanical
strengths, for example 7 days or 28 days after mixing. This decrease is in particular due
to the decrease of the quantity of clinker relative to the total quantity of binder, given that
the binder generally comprises clinker and mineral additions.
Several solutions exist to improve the compressive mechanical strengths of
hydraulic compositions comprising a low quantity of clinker, but generally these solutions
only improve the compressive mechanical strengths for one time period, for example
28 days after mixing.
Other solutions exist but require adding admixtures, which is to say organic
materials in a mineral material.
In order to meet user requirements, it has become necessary to find a new means
to improve compressive mechanical strengths of hydraulic compositions comprising a
low quantity of Portland clinker, whatever the time period beyond 2 days after mixing,
preferably from 7 days after mixing.
Therefore, the problem which the invention seeks to solve is to provide a means to
improve the compressive mechanical strengths of hydraulic compositions comprising a
low quantity of Portland clinker, whatever the time period beyond 2 days after mixing,
preferably from 7 days after mixing.
Unexpectedly, the inventors have shown that it is possible to combine three
different mineral additions to improve the compressive mechanical strengths of hydraulic
compositions comprising a low quantity of Portland clinker, whatever the time period
beyond 2 days after mixing, preferably from 7 days after mixing.
The present invention relates to a hydraulic binder comprising:
25 to 60 % by mass of Portland clinker;
5 to 15 % by mass of a first mineral addition selected from:
o mineral additions reacting with at least 400 mg/g of CaO according to the
method at 90°C described in the NF P 18-513 Standard of December 30,
201 1, in Appendix A, and
o latent hydraulic materials;
a second mineral addition reacting with less than 400 mg/g of CaO according to
the method described herein above; and
either a third mineral addition with a base of calcium carbonate or calcium
sulphate, or both;
the hydraulic binder comprising at least 1 %, preferably 1 to 10 %, more preferably
1 to 8 % by mass of reactive aluminium, which is to say, that contributes to the
development of strengths.
Within the NF P 18-513 Standard of December 30, 201 1, in Appendix A paragraph
A.4.1 page 17 line 19, it is specified that when the procedure is conducted at 90°C, the
temperature of the reaction medium is controlled to be at 85±5°C.
The reactive aluminium may be provided by the Portland clinker, by the first
mineral addition and/or by the second mineral addition. In the case of Portland clinker,
the reactive aluminium is provided by the C3A mineral phase.
Advantageously, the hydraulic composition according to the present invention
makes it possible to obtain a compressive mechanical strength of at least 35 MPa,
preferably at least 45 MPa 28 days after mixing. Certain optimised formulae according to
the present invention make it even possible to obtain a compressive mechanical
strength 28 days after mixing of at least 55 MPa.
Advantageously, the hydraulic composition according to the present invention
makes it possible to obtain a compressive mechanical strength of at least 10 MPa,
preferably at least 15 MPa 2 days after mixing. Certain optimised formulae according to
the present invention make it even possible to obtain a compressive mechanical
strength of at least 20 MPa 2 days after mixing.
Advantageously, the rheology of the hydraulic composition according to the
present invention is such that it can be used as an ordinary hydraulic composition.
Advantageously, the addition of only 5 to 15 % by mass of a first mineral addition
relative to the mass of binder (the binder comprising the Portland clinker, the mineral
additions and optionally calcium sulphate), for example blast furnace slag, silica fume,
metakaolin, a diatomite or biomass ash, in combination with a second mineral addition
and either a third mineral addition with a base of calcium carbonate or calcium sulphate
or both, makes it possible to improve the compressive strength of a hydraulic
composition comprising 25 to 60 % by mass of Portland clinker, relative to the mass of
binder.
As illustrated in the examples herein after, it was observed that the addition of
more than 10%, preferably more than 5 % by mass of a third mineral addition with a
base of calcium carbonate, relative to the mass of binder (the binder comprising the
Portland clinker, mineral additions and optionally calcium sulphate) does not make it
possible to substantially increase the compressive strength. It is thus possible to add
more than 10 %, preferably more than 5 % by mass of the third mineral addition, but
there is no advantage linked to this higher quantity.
A Portland clinker is obtained by clinkering at high temperature a mix comprising
limestone and, for example clay. For example, a Portland clinker is a clinker as defined
in the NF EN 197-1 Standard of February 2001 .
Preferably, the quantity of Portland clinker in the hydraulic binder according to the
present invention is from 45 to 55 % by mass relative to the mass of binder.
Preferably, the Blaine specific surface of the Portland clinker is from 3000 to
9000 cm2/g, more preferably from 3200 to 6500 cm2/g.
Mineral additions are generally for example slags (for example as defined in the
"Cement" NF EN 197-1 Standard of February 2001 , paragraph 5.2.2), natural or artificial
pozzolans (for example as defined in the "Cement" NF EN 197-1 Standard of February
2001 , paragraph 5.2.3), fly ash (for example as defined in the "Cement" NF EN 197-1
Standard of February 2001 , paragraph 5.2.4), calcined shales (as defined in the
« Cement » NF EN 197-1 Standard, paragraph 5.2.5), mineral additions with a base of
calcium carbonate, for example limestone (for example as defined in the" Cement" NF
EN 197-1 Standard paragraph 5.2.6) silica fume (for example as defined in the
"Cement" NF EN 197-1 Standard of February 2001 , paragraph 5.2.7), metakaolins, ash
obtained from biomass (for example rice husk ash) or mixtures thereof.
A first mineral addition is either:
- a mineral addition reacting with at least 400 mg/g of CaO according to the
modified Chapelle test at 90°C, described in the NF P 18-513 Standard of
December 30, 201 1, in particular in Appendix A. This mineral addition is a
pozzolanic material; or
- a latent hydraulic material, for example a blast furnace slag. A latent hydraulic
material is a material which, by the effect of alkali activation, can develop
mechanical strengths by itself in water. A latent hydraulic material does not
react by itself in water without alkali activation.
Preferably, the latent hydraulic material used according to the present invention is
a blast furnace slag.
Preferably, the first mineral addition is selected from blast furnace slags, silica
fume, metakaolins, biomass ash (for example rice husk ash, rice straw, sugar cane,
maize, wheat sorghum or bread fruit), sedimentary pozzolans (for example diatomites),
weathered pozzolans (for example, zeolites) and mixtures thereof.
Preferably, the first mineral addition is selected from blast furnace slags, silica
fume, metakaolins, biomass ash and mixtures thereof.
Silica fume generally comprises more than 80 % of silicon dioxide.
Preferably, if the first mineral addition is siliceous (for example a silica fume or
biomass ash), its content in the hydraulic binder according to the present invention is
from 10 to 15 % by mass.
Preferably, if the first mineral addition is a blast furnace slag, it comprises a
content of amorphous phase greater than 70 % by mass and/or it has a Blaine specific
surface greater than 4500 cm2/g, preferably greater than 6000 cm2/g. The content of the
amorphous phase may be determined according to the method described herein after
before the examples.
Preferably, if the first mineral addition is a silica fume it has a Blaine specific
surface greater than 20000 cm2/g.
Preferably, if the first mineral addition is a metakaolin, it is obtained at a
temperature of 500 to 700°C, more preferably from 600 to 700°C.
Preferably, if the first mineral addition is a metakaolin, it comprises more than
15 % by mass of reactive aluminium.
In the case of a pozzolanic material, the reactive aluminium is generally aluminium
that reacts with calcium hydroxide during the pozzolanic reaction to form hydrates and
participate in the development of strengths of a binder comprising the said pozzolanic
material. In this case, the content of reactive aluminium may be determined according to
the method described herein after before the examples.
In the case of a latent hydraulic material or clinker, the reactive aluminium is the
aluminium which participates in the formation of hydrates and in the development of
strengths of a binder comprising said latent hydraulic material or said clinker. In the case
of a latent hydraulic material, the content of reactive aluminium may be determined by
dosing the content of Al20 3 in the material. In the case of clinker, the content of reactive
aluminium may be determined by the sum of the cubic and orthorhombic C3A phases
and by X-ray diffraction and Rietveld analyses. The C3A phases are mineral phases of
clinkers known by the person skilled in the art.
Preferably, if the first mineral addition is a metakaolin, it comprises a content of
aluminium less than or equal to 50 % by mass.
Biomass ash is generally obtained from plant waste comprising silica with a
content of Si0 2 greater than 70 % by mass. Biomass, which may be used according to
the present invention, makes it possible to obtain 10 to 20 % by mass of ash relative to
the mass of plant waste before calcination.
Preferably, if the first mineral addition is biomass ash, it is obtained at a
temperature of 500 to 700°C, preferably 600 to 700°C.
A second mineral addition is a mineral addition reacting with less than 400 mg/g of
CaO according to the modified Chapelle test at 90°C described in the NF P 18-513
Standard of December 30, 201 1, in particular Appendix A.
Preferably, the second mineral addition used according to the present invention
comprises less than 15 % by mass of reactive aluminium, determined according to the
method described herein after before the examples.
Preferably, the second mineral addition is present in such a quantity that it
completes up to 100 % the quantity of the other components of the binder.
Preferably, the quantity of the second mineral addition is at least 23 % by mass
relative to the mass of binder.
Preferably, the second mineral addition is selected from pozzolans of volcanic
origin, fly ash, quartz and mixtures thereof.
A pozzolan is described in Lea's Chemistry of Cement and Concrete, 4th edition,
published by Arnold, as an inorganic material, natural or synthetic, which hardens in
water when mixed with calcium hydroxide (lime) or with a material which can release
calcium hydroxide (such as Portland cement clinker). This hardening capacity is called
pozzolanic activity. A pozzolan is generally a siliceous or siliceous and aluminous
material which, alone, possesses little or no cementitious value but which is capable, in
the presence of moisture, of reacting chemically with calcium hydroxide at ambient
temperature to form compounds having cementitious properties
Fly ash is generally pulverulent particles contained in the fume in thermal power
plants fed with coal. It is generally obtained by electrostatic or mechanical precipitation.
The chemical composition of a fly ash mainly depends on the chemical
composition of the unburned carbon and on the process used in the thermal power plant
from where it came. The same can be said for its mineralogical composition.
Preferably, the third mineral addition with a base of calcium carbonate is present in
the hydraulic binder according to the present invention.
Preferably, the quantity of the third mineral addition with a base of calcium
carbonate is at most 10 %, preferably at most 6 %, more preferably at most 5 % by
mass relative to the mass of binder. According to an embodiment, the quantity of the
third mineral addition with a base of calcium carbonate is from 2 to 10 % by mass
relative to the mass of binder.
Preferably, the mass ratio of the first mineral addition to the third mineral addition
with a base of calcium carbonate is from 1 to 15, more preferably from 1 to 10, most
preferably from 1 to 5, for example 1.5.
A Portland clinker is generally co-ground with calcium sulphate to produce cement.
The calcium sulphate includes gypsum (calcium sulphate dihydrate, CaS0 4.2H20),
hemi-hydrate (CaS0 4.1/2H20), anhydrite (anhydrous calcium sulphate, CaS0 4) or a
mixture thereof. The gypsum and anhydrite exist in the natural state. It is also possible
to use a calcium sulphate which is a by-product of certain industrial processes.
Preferably, the content of calcium sulphate is from 0 to 7 % by mass relative to the
mass of binder.
Preferably, the third mineral addition with a base of calcium carbonate and/or
calcium sulphate is present in the hydraulic binder according to the present invention.
A hydraulic binder is a material which sets and hardens by hydration, for example
a cement. A cement generally comprises a clinker and calcium sulphate.
For example, the cement may be:
- a Portland cement, which is generally a cement of type CEM I according to the
NF EN 197-1 Standard of February 2001 (see Table 1 page 12 in the standard);
- a pozzolanic cement, which is generally a cement of type CEM IV according to
the NF EN 197-1 Standard of February 2001 (see Table 1 page 12 in the standard); or
- a blended cement, which is generally a cement of type CEM II, CEM III or CEM V
according to the NF EN 197-1 Standard of February 2001 (see Table 1 page 12 in the
standard).
It is to be understood that by replacing part of the clinker with a mineral addition it
is possible to reduce emissions of carbon dioxide (produced during the production of the
clinker) by reducing the content of clinker, whilst still obtaining the same mechanical
strengths.
The present invention also relates to a process for production of the hydraulic
binder according to the present invention, comprising a step of mixing the different
constituents. According to an embodiment of the present invention, at least two of the
different constituents of the binder are co-ground.
The present invention also relates to a hydraulic composition comprising the
hydraulic binder according to the present invention and water.
A hydraulic composition generally comprises a hydraulic binder and water,
optionally aggregates and optionally admixtures. Hydraulic compositions include both
fresh compositions and hardened compositions, for example, a cement slurry, a mortar
or a concrete. The hydraulic composition may be used directly on a jobsite in the fresh
state and poured into formwork adapted to a given application; it may be used in a pre
cast plant or as coating on a solid support.
A hydraulic composition generally comprises different types of water, in particular
the total water and the effective water. The total water is the water added during the
mixing of the hydraulic composition.
The effective water is the water required to hydrate the hydraulic binder and to
provide fluidity of a fresh hydraulic composition. The total water represents the totality of
the water present in the mix (at the time of mixing) and comprises the effective water
and the water absorbed by the aggregates. Effective water and its calculation are
discussed in the EN 206-1 standard of October 2005, page 17, paragraph 3.1 .30.
The quantity of absorbable water is deduced from the coefficient of absorption of
the aggregates measured according to the NF EN 1097-6 Standard of June 2001 , page
6 paragraph 3.6 and the associated Appendix B. The absorption coefficient of water is
the ratio of the increase in mass of a sample of aggregates, relative to its dry mass, the
sample being initially dried then submerged for 24 hours in water. The increase of mass
is due to the water penetrating in the pores of the aggregates accessible to the water.
The quantity of water is preferably such that the effective water/binder ratio is from
0.2 to 0.7, more preferably from 0.4 to 0.6, the binder being the hydraulic binder
according to the present invention.
The aggregates include sand (whose particles generally have a maximum size
(Dmax) of less than or equal to 4 mm), and gravel (whose particles generally have a
minimum size (Dmin) greater than 4 mm and preferably a Dmax less than or equal to
20 mm).
The aggregates include calcareous, siliceous, and silico-calcareous materials.
They include natural, artificial, waste and recycled materials. The aggregates may also
comprise, for example, wood.
The hydraulic composition may also comprise an admixture, for example one
described in the EN 934-2 Standard of September 2002, the EN 934-3 Standard of
November 2009 or the EN 934-4 Standard of August 2009. Preferably the hydraulic
composition also comprises an admixture for hydraulic compositions, for example an
accelerator, an air-entraining agent, a viscosity-modifying agent, a retarder, a clayinerting
agent, a plasticizer and/or a superplasticizer. In particular, it is useful to include
a polycarboxylate superplasticizer, in particular from 0.05 to 1.5%, preferably from 0.1 to
0.8%, by mass relative to the mass of binder.
Clay inerting agents are compounds which permit the reduction or prevention of
the harmful effect of clays on the properties of hydraulic binders. Clay inerting agents
include those described in WO 2006/032785 and WO 2006/032786.
The term superplasticizer as used in the present description and the
accompanying claims is to be understood as including both water reducers and
superplasticizers as described in the Concrete Admixtures Handbook, Properties
Science and Technology, V.S. Ramachandran, Noyes Publications, 1984.
A water reducer is defined as an admixture which reduces the amount of mixing
water of concrete for a given workability by typically 10 - 15%. Water reducers include,
for example lignosulphonates, hydroxycarboxylic acids, glucides, and other specialized
organic compounds, for example glycerol, polyvinyl alcohol, sodium alumino-methylsiliconate,
sulfanilic acid and casein.
Superplasticizers belong to a new class of water reducers, chemically different
from typical water reducers and capable of reducing water contents by about 30%. The
superplasticizers have been broadly classified into four groups: sulphonated
naphthalene formaldehyde condensate (SNF) (generally a sodium salt); sulphonated
melamine formaldehyde condensate (SMF); modified lignosulfonates (MLS); and others.
More recent superplasticizers include polycarboxylic compounds such as
polycarboxylates, for example polyacrylates. The superplasticizer is preferably a new
generation superplasticizer, for example a copolymer containing polyethylene glycol as
graft chain and carboxylic functions in the main chain such as a polycarboxylic ether.
Sodium polycarboxylate-polysulphonates and sodium polyacrylates may also be used.
Phosphonic acid derivatives may also be used. The amount of superplasticizer required
generally depends on the reactivity of the cement. The lower the reactivity, the lower the
amount of superplasticizer required. In order to reduce the total alkaline metal salt
content the superplasticizer may be used as a calcium rather than a sodium salt.
The present invention also relates to a process for production of the hydraulic
composition according to the present invention, comprising a step of mixing the
hydraulic binder according to the present invention and water.
The mixing of the hydraulic composition may be carried out, for example,
according to known methods.
According to an embodiment of the invention, the binder is prepared during a first
step and the optional aggregates and the water are added during a second step.
The hydraulic composition according to the present invention may be shaped to
produce, after hydration and hardening a shaped article for the construction field. The
invention also relates to such a shaped object, which comprises a hydraulic composition
according to the present invention. Shaped articles for the construction field include, for
example, a floor, a screed, a foundation, a wall, a partition wall, a ceiling, a beam, a
work top, a pillar, a bridge pier, a masonry block of concrete, a conduit, a post, a stair, a
panel, a cornice, a mould, a road system component (for example a border of a
pavement), a roof tile, surfacing (for example of a road or a wall), or an insulating
component (acoustic and/or thermal).
The present invention also relates to a use of at least three different mineral
additions to improve the compressive mechanical strength of a hydraulic composition
comprising 25 to 60 % of Portland clinker by mass relative to the mass of binder,
whatever the time period beyond 2 days after mixing, preferably from 7 days after
mixing, (the binder comprising the Portland clinker, the mineral additions and the
optional calcium sulphate), said at least three different mineral additions being:
- from 5 to 15 % of a first mineral addition as described herein above;
- a second mineral addition as described herein above; and
- either a third mineral addition with a base of calcium carbonate or calcium
sulphate, or both.
Preferably, the third mineral addition with a base of calcium carbonate is present in
the use according to the present invention.
Preferably, the third mineral addition with a base of calcium carbonate and the
calcium sulphate calcium are both present in the use according to the present invention.
The characteristics of the different constituents of the binder according to the
present invention apply to all the objects according to the present invention.
The Dv90 is the 90th percentile of the size distribution of the particles, by volume;
that is, 90% of the particles have a size that is less than or equal to Dv90 and 10% of
the particles have a size that is greater than Dv90. The Dv50 is defined in a similar
manner.
Particle size distributions and particle sizes less than about 200 m h are measured
using a Malvern MS2000 laser granulometer. Measurement is carried out in ethanol.
The light source consists of a red He-Ne laser (632 nm) and a blue diode (466 nm). The
optical model is that of Mie and the calculation matrix is of the polydisperse type.
The apparatus is calibrated before each working session by means of a standard
sample (Sifraco C10 silica) for which the particle size distribution is known.
Measurement is carried out with the following parameters: pump speed: 2300 rpm
and stirrer speed: 800 rpm. The sample is introduced in order to establish an
obscuration from 10 to 20%. Measurement is carried out after stabilisation of the
obscuration. Ultrasound at 80% is applied for 1 minute to ensure the de-agglomeration
of the sample. After approximately 30 seconds (for possible air bubbles to clear), a
measurement is carried out for 15 seconds (15000 analysed images). The measurement
is repeated at least twice without emptying the cell to verify the stability of the result and
elimination of possible bubbles.
All values given in the description and the specified ranges correspond to average
values obtained with ultrasound.
Particle sizes greater than 200mhi are generally determined by sieving.
The Blaine specific surface is measured at 20°C with relative humidity not
exceeding 65 % using a Blaine Euromatest Sintco apparatus in accordance with the
European EN 196-6 Standard of August 1990. Prior to the measurement of the specific
surface, the humid samples are dried in a drying oven until obtaining a constant mass at
a temperature of 50 to 150°C (the dried product is then ground to produce a powder, all
of which has a maximum particle size less than or equal to 80 m h ) .
In the present description including the accompanying claims, percentages, unless
otherwise specified, are by mass.
Determination of the content of reactive aluminium for mineral additions as defined
herein above
The quantity of reactive aluminium can be determined according to the protocol
herein below:
- introduce 1 gram of the material to be analyzed into a test tube;
- add 10 mL of concentrated nitric acid (solution at 69.5 % dry extract);
- plug the test tube and shake manually;
- place the test tube in a low-boiling water bath for 4 hours;
- leave to cool to room temperature;
- transfer the contents of the test tube into a 100 mL flask;
- add 2 mL of potassium chloride (solution at 5 % dry extract);
- add a sufficient quantity of distilled water to reach 100 mL;
- shake manually and filter (filter: 45 m h ) ;
- analyze the filtrate by an appropriate analysis method, for example using an
inducted plasma spectrometer (ICP);
- determine the mass percentage of reactive aluminium.
Determination of the content of reactive silica
The quantity of reactive silica (in the form of silicon dioxide according to the
EN 197-1 Standard of February 2001 ) , can be determined according to the protocol
described in the EN 196-2 Standard of April 2006, paragraph 10.
Reactive silica can be assimilated to the proportion of silicon dioxide which
dissolves after an attack by hydrochloric acid (dilution to 1/10 of a solution of HCI at
37 % dry extract), or when it is boiled in a solution of potassium hydroxide (solution of
KOH at 25 % dry extract). The dosage of the reactive silica can be determined by the
difference between the total silica of the material to be analyzed, determined by X-ray
fluorescence, and the silica of the insoluble residue obtained after the attack by
hydrochloric acid, followed by potash, also determined by X-ray fluorescence.
Determination of the level of amorphous phase in a material
A mix is made (generally 50/50 by mass) with the material to be analyzed and a
completely crystallized reference compound for which the composition is known (for
example, rutile, alumina or zircon). The mix should be completely homogenized and the
relative proportions of the material to be analyzed and the reference compound should
be known with precision. The selected reference compound is preferably different to the
crystals which can be found in the material to be analyzed. In all cases, in order to not
distort the quantitative measurement, a reference compound is selected which is close
to the crystals present in the material to be analyzed, in terms of intensity of the
response, as known in the domain of X-ray diffraction.
A quantitative measurement of the mix is carried out, for example using the
quantitative X-ray diffraction method (refer to the publication Quantitative X-Ray
Diffraction Analysis, L.E. Copeland and R.H. Bragg, Analytical Chemistry, p.196).
The nature and quantity of crystals present in the mix is obtained. The amorphous
phase does not diffract X rays and therefore does not appear in the results of the
quantitative measurement. The level of amorphous phase (AP) in mass percentage
relative to the mass of the material to be analyzed can be determined according to
Formula (I):
AP = 100 x [100 (100 - Xo)] x [ 1 - (Xo Xm)]
Formula (I)
wherein X0 represents the mass percentage of the reference compound in the mix
(material to be analyzed + reference compound);
Xm represents the mass percentage of the reference compound
determined by the quantitative measurement.
In the case where the reference material is a crystalline phase also present in the
material to be analyzed, the quantitative measurement is first applied separately to the
material to be analyzed and to the reference material, in order to determine the quantity
of said crystalline phase in the material to be analyzed. Thus, by knowing the quantity of
the crystalline phase in the material to be analyzed and the relative proportion of the
material to be analyzed and the reference material, it is possible to determine Xm. It is
then possible to apply Formula (I).
The following non-limiting examples illustrate embodiments of the invention.
EXAMPLES
The tested hydraulic composition in Examples 1 to 6 was a mortar, the formulation
of which is described in the following tables.
The standardized sand was a siliceous sand according to the EN 196-1 Standard
of April 2006, the supplier being Societe Nouvelle du Littoral.
The cement was a CEM I 52.5 N cement from the Lafarge Saint Pierre La Cour
cement plant, having a Blaine specific surface of approximately 3000 cm2/g. The cement
comprised 95.2 % by mass of Portland clinker, 2.8 % of hemi-hydrate, 1. 1 % of gypsum
and 0.9 % of calcite.
The first mineral addition was either:
a blast furnace slag from Dunkerque in France, having approximately 98 % by
mass of amorphous phase, a Blaine specific surface of approximately
8000 cm2/g, a Dv50 of approximately 5 m h and a Dv90 of approximately 9 mhi ;
- or a metakaolin having 40 to 60 % by mass of amorphous phase, a Blaine
specific surface of approximately 7000 cm2/g, a Dv50 of approximately 4 1 m h
and a Dv90 of approximately 135 m h , which is sold under the brand name of
Argicem by Mallet (MK1), or a metakaolin having 60 to 80 % by mass of
amorphous phase, a Blaine specific surface of approximately 35000 cm2/g, a
Dv50 of approximately 6 m h and a Dv90 of approximately 17 m h , which is sold
under the brand name of Argical M 1200S by AGS (MK2);
or silica fume having 80 to 100 % by mass of amorphous phase, a Blaine
specific surface of approximately 28000 cm2/g, a Dv50 of approximately 3 m h
and a Dv90 of approximately 16 m h , which is sold under the brand name of
Deng Feng by Saint-Gobain Ceramic Materials;
or rice husk ash having 80 to 100 % by mass of amorphous phase, a Blaine
specific surface of approximately 10400 cm2/g, a Dv50 of approximately 20 m h
and a Dv90 of approximately 5 1 m h , which is sold under the brand name of
Silpozz 4 by NK Enterprises.
The second mineral addition was either:
- quartz having a Blaine specific surface of approximately 6500 cm2/g and a Dv50
of approximately 12 m h , which is sold under the brand name of C400 (Quartz C400 -
Supplier: Sibelco);
- or pozzolans from Voutre in France having a Blaine specific surface of
approximately 6800 cm2/g and a Dv50 of approximately 14 m h (Pozz. Voutre),
pozzolans from Thueyts in France having a Blaine specific surface of approximately
5500 cm2/g and a Dv50 of approximately 10 m h (Pozz. Thueyts) or pozzolans from
Villaluenga in Spain having a Blaine specific surface of approximately 7400 cm2/g and a
Dv50 of approximately 8 m h (Pozz. Villaluenga).
In the preceding raw materials, the quantities of reactive aluminium and reactive
silica, and to the results of the modified Chapelle test as described herein above are
recorded in Table 1 herein after:
Tablel :
The third mineral addition with a base of calcium carbonate was a limestone sold
under the brand name of BL200 (Supplier: Omya).
The calcium sulphate was anhydrite from eastern France, comprising
approximately 53 % by mass of S0 3, added in order to obtain 3.5 % of S0 3 in the
binder.
The mortar was produced according to the protocol described in the EN 196-1
Standard of April 2006, paragraph 6.
Measurement of the compressive mechanical strengths was carried out on
samples of hardened mortar in the shape of bricks with a dimension of 40 mm x 40 mm
x 160 mm.
The samples of mortar were moulded immediately after preparation of the mortar.
The mould was fastened to a shock table. The mortar was introduced into the mould in
two layers (each layer of mortar weighing approximately 300 g). The first layer of mortar,
then the second layer of mortar were poured, then submitted to 60 shocks on the shock
table. The mould was removed from the shock table and levelled to remove the excess
mortar. A glass plate: 210 mm x 185 mm and thickness: 6 mm was placed on the mould.
The mould covered by the glass plate was placed in a humid enclosure. The mould was
removed from the enclosure and the sample of hardened mortar was de-moulded
24 hours after mixing, then it was submerged in water at 20°C ± 1°C. The sample of
hardened mortar was removed from the water 15 minutes maximum before
measurement of the compressive mechanical strength. The sample of hardened mortar
was dried, then covered with a damp cloth until the compressive strength measurement.
For the measurement of the compressive mechanical strength, an increasing load
was applied on the lateral sides of the sample of hardened mortar at a speed of
2 400 N/s ± 200 N/s, until rupture of the sample.
Each of the formulations tested in Examples 1 to 6 herein after comprised one part
by mass of binder and 3 parts by mass of standardized sand and had a water/binder
ratio of 0.5. 450 grams of binder were used, given that the binder comprised:
- 55 % by mass of cement (52.4 % of clinker, 1.5 % of hemi-hydrate, 0.6 % of
gypsum and 0.5 % of calcite); and
- 45 % of an addition (a first mineral addition, a second mineral addition, a third
mineral addition with a base of calcium carbonate and/or calcium sulphate).
Example 1: Hydraulic compositions comprising rice husk ash as a first mineral
addition
Different formulae comprising a rice husk ash as the first mineral addition were
tested for their compressive mechanical strengths at different time periods. Table 2
below presents the obtained results.
Table 2 : Compositions and results obtained for Example 1
The percentages are mass percentages
MA1 : first mineral addition; when present in the formulae, the quantity was
approximately 15% by mass
MA2: second mineral addition
MA3: third mineral addition with a base of calcium carbonate
According to Table 2 herein above, the mortars according to the present invention
(Mortars 1 to 10) had better compressive strengths (at 7 days, 28 days and 90 days
after mixing) than the controls, even those which had a first mineral addition (Controls 1
to 5).
Example 2 : Hydraulic compositions comprising silica fume as a first mineral
addition
Different formulae comprising silica fume as a first mineral addition were tested for
their compressive strengths at different time periods. Table 3 below presents the
obtained results.
Table 3 : Compositions and results obtained for Example 2
Al20 3 Compressive strength [MPa)
% % % % MA1 MA2 MA2 mass MA3 CaS0 4 1 2 7 28 90
/binder day days days days days
CCo4n0tr0ol None QCu4a0r0tz 45 1.4 0 0 9 .1 - 2 1.8 29.9 33. 1
Control Silica Quartz
6 fume C400 30 1.4 0 0 9.0 - 22.3 38.9 53.5
Mortar Silica Quartz
11 fume C400 20 1.4 10 0 7.5 - 26.0 45.3 58.7
Control Pozz.
Voutre Voutre 45 2.6 0 0 - 13.0 18.9
Control Pozz.
7 None Voutre 30 2.2 0 0 - 13.5 2 1.5 35.0
Mortar Silica Pozz.
12 fume Voutre 25 2 .1 5 0 - 14.7 25.9 43. 1
Mortar Silica Pozz.
13 fume Voutre 2 1 2.0 5 4.44 - 13.2 25.8 43.5
Control Silica Pozz.
Villa. fume Villaluenga 45 4.8 0 0 8.5 - 25.4 34.5 42.5
Control Pozz.
8 Villaluenga 30 3.7 0 0 9.7 - 25.5 4 1.9 57.6
Mortar Pozz.
None 30 3.7 0 3 .11 9.5 - 29.0 14 Villaluenga 49. 1 64.8
Control Silica Pozz.
Thueyts fume Thueyts 45 4.6 0 0 - 15.0 22.9
Control Silica Pozz.
9 fume Thueyts 30 3.6 0.0 0.0 - 13.5 2 1.6 37. 1
Mortar Pozz.
15 Thueyts 25.6 3.2 0.0 4.4 - 12.2 25.8 42.6
Mo1r6tar None TPhuoezyzt.s 25 3.2 5 0 - 15.2 27.8 46. 1
Mortar Silica Pozz.
17 fume Thueyts 20.6 2.9 5 4.4 - 11.8 25.8 43.6
The percentages are mass percentages
MA1 : first mineral addition; when present in the formulae, the quantity was
approximately 15% by mass
MA2: second mineral addition
MA3: third mineral addition with a base of calcium carbonate
According to Table 3 herein above, the mortars according to the present invention
(Mortars 11 to 1 ) had better compressive strengths (at 7 days, 28 days and 90 days
after mixing) than the controls, even those which had a first mineral addition (Controls 6
to 9).
Example 3 : Hydraulic compositions comprising a metakaolin as a first mineral
addition
Different formulae comprising silica fume as a first mineral addition were tested for
their compressive strengths at different time periods. Table 4 below presents the
obtained results.
Table 4 : Compositions and results obtained for Example 3
Al20 3 Compressive strength (MPa)
% % % % MA1 MA2 MA2 mass MA3 CaS0 4 1 2 7 28 90
/binder day days days days days
Control Quartz
C400 None C400 45 1.4 0 0 9 .1 - 2 1.8 29.9 33. 1
Control Quartz
10 MK1 C400 30 4.3 0 0 8 .1 - 22.6 33.0 37.3
Mortar Quartz
18 MK1 C400 30 4.3 0 3 .11 7.9 - 27.42 36.61 42.39
Mortar Quartz
MK1 20 4.3 10 0 8.0 - 30.4 40.7 46.9
19 C400
Control Quartz
11 MK2 C400 30 7.0 0 0 9.4 - 29.6 40.5 45.3
Mortar Quartz
MK2 30 70 0 3 .11 13.2 - 38.2 47. 1 5 1.9 20 C400
Mortar Quartz
MK2 20 4.3 10 0 9.4 - 37.9 50.0 53. 1 2 1 C400
Control Pozz.
Voutre Voutre 45 2.6 0 0 - 13.0 18.9
Control Pozz.
12 None Voutre 30 7.8 0 0 - 15.4 29.7 38.3
Mortar Pozz.
22 MK2 Voutre 25 7.7 5 0 - 19.5 40,9 48,7
Mortar Pozz.
MK2 2 1 7.6 5 4.44 - 24.7 45,3 53,2 23 Voutre
Control Pozz.
MK2 45 4.8 0 0 8.5 - Villa. Villaluenga 25,4 34.5 42.5
Control Pozz.
13 Villaluenga 30 6.5 0 0 7.9 - 25,9 35.9 45.5
Mortar Pozz.
24 None Villaluenga 30 6.5 0 3 .11 9.2 - 28,8 42.4 49.7
Control Pozz.
14 MK1 Villaluenga 30 9.3 0 0 11.3 - 32,4 43.5 49.7
Mortar Pozz.
25 MK1 Villaluenga 30 9.3 0 3 .11 14.5 - 39,4 49. 1 55.3
Control Pozz.
Thueyts MK2 Thueyts 45 4.6 0 0 - 15.0 22.9
Control Pozz.
15 MK2 Thueyts 30 9.2 0 0 - 15.5 28.8 38.9
Mortar Pozz.
25.6 8.8 0 4,4 - 23.9 39.0 47.2 26 Thueyts
Mortar Pozz.
27 None Thueyts 25 8.8 5 0 - 18.0 39.7 49.3
Mortar Pozz.
28 MK2 Thueyts 20.6 8.5 5 4,4 - 2 1.6 42.5 50.3
he percentages are mass percentages
MA1 : first mineral addition; when present in the formulae, the quantity was
approximately 15% by mass
MA2: second mineral addition
MA3: third mineral addition with a base of calcium carbonate
According to Table 4 herein above, the mortars according to the present invention
(Mortars 18 to 28) had better compressive strengths (at 7 days, 28 days and 90 days
after mixing) than the controls, even those which had a first mineral addition (Controls
10 to 15).
Advantageously, the mortars according to the present invention comprising MK2
(Mortars 22, 23 and 26 to 28) also had a better compressive strength 2 days after mixing
than those of the corresponding controls (controls Voutre, 12, Thueyts and 15).
Example 4 : Hydraulic compositions comprising different quantities of metakaolin
as a first mineral addition
Different formulae comprising a metakaolin as a first mineral addition in different
quantities were tested for their compressive strengths at different time periods. The aim
was to verify whether the compositions according to the present invention satisfied the
criteria of the EN 197-1 Standard of February 2001 in Table 2, in terms of compressive
strength and determine in which categories they could be classed according to this
standard. The classes as defined according to the standard given herein above are, in
particular, the following:
32.5 R: compressive strength greater than or equal to 10 MPa 2 days after
mixing and greater than or equal to 32.5 MPa 28 days after mixing;
42.5 N: compressive strength greater than or equal to 10 MPa 2 days after
mixing and greater than or equal to 42.5 MPa 28 days after mixing; and
52.5 N: compressive strength greater than or equal to 20 MPa days after
mixing and greater than or equal to 52.5 MPa 28 days after mixing.
Table 5 below presents the obtained results.
Table 5 : Compositions and results obtained for Example 4
The percentages are mass percentages
MA1 : first mineral addition; when present in the formulae, the quantity was
approximately 15% by mass
MA2: second mineral addition
MA3: third mineral addition with a base of calcium carbonate
According to Table 5 herein above, the mortars according to the present invention
(Mortars 29 to 31) had sufficient compressive strength to satisfy the criteria of the EN
197-1 Standard of February 2001 , Table 2.
Example 5 : Hydraulic compositions comprising a metakaolin as a first mineral
addition and different guantities of limestone
Different formulae comprising a metakaolin as a first mineral addition and different
quantities of limestone were tested for their compressive strength at different time
periods. Table 6 herein after presents the obtained results.
Table 6 : Compositions and results obtained for Example 5
The percentages are mass percentages
MA1 : first mineral addition; when present in the formulae, the quantity was
approximately 15% by mass
MA2: second mineral addition
MA3: third mineral addition with a base of calcium carbonate
According to Table 6 below, the addition of 5 % of limestone was sufficient to
obtain better compressive strengths (at 7 days and 28 days after mixing) compared to
the controls (Controls C400 and 16). A supplementary addition of limestone did not
significantly improve the compressive strengths (Mortars 33, 34, 37 and 38) compared
to Mortars 32 and 35.
Advantageously, better compressive strengths were obtained for the mortars
comprising both anhydrite and limestone (Mortars 36 to 38).
Example 6 : Hydraulic compositions comprising a blast furnace slag as a first
mineral addition
Different formulae comprising a blast furnace slag as a first mineral addition were
tested for their compressive strengths at different time periods. Table 7 below presents
the obtained results.
Table 7: Compositions and results obtained for Example 6
The percentages are mass percentages
MA1 : first mineral addition; when present in the formulae, the quantity was
approximately 15% by mass
MA2: second mineral addition
MA3: third mineral addition with a base of calcium carbonate
According to Table 7 herein above, the mortars according to the present invention
(Mortars 39 to 46) had better compressive strengths (at 7 days, 28 days and 90 days
after mixing) than the controls, even those which had a first mineral addition (Controls
17 to 20).
Example 7: Production of concretes
Concretes were produced from the hydraulic binders according to the present
invention. The aim was to verify that at least 25/30 MPa was indeed obtained 28 days
after mixing. It was also possible to compare it with a concrete comprising 100 % of
CEM I 52.5 N Portland cement.
In addition to the raw materials described for the previous examples, the following
raw materials were used:
Aggregates: each aggregate was characterised by two numbers: the first
corresponds to « d » as defined in the XPP 18-545 Standard and the second
corresponds to « D » as defined in the XPP 18-545 Standard of February 2004:
- Sand 1 was a 0/1 river silico-calcareous sand from the Lafarge quarry of St
Bonnet;
- Sand 2 was a 1/5 river silico-calcareous sand from the Lafarge quarry of St
Bonnet;
- Sand 3 was a 5/10 river silico-calcareous sand from the Lafarge quarry of St
Bonnet;
- the coarse gravel was 10/20 river silico-calcareous coarse gravel from the
Lafarge quarry of St Bonnet.
The superplasticizers were the following:
SP: polycarboxylate superplasticizer in solution (20 % dry extract) (Supplier:
CHRYSO; commercial brand name: Optima 203);
The concrete was produced according to the procedure described below:
1) introduce the sands and aggregates in the bowl of a Perrier mixer;
2) from 0 to 30 seconds: begin mixing at low speed (140 rpm) and introduce the
pre-wetting water in 30 seconds;
3) from 30 seconds to 1 minute: mix the aggregates and pre-wetting water for 30
seconds;
4) from 1 minute to 5 minutes: leave to rest for 4 minutes;
5) from 5 minutes to 6 minutes: introduce the clinker, the mineral additions, the
limestone and the anhydrite; this is TO for the mixing, from which time the
measurement time periods of the mechanical strengths are determined;
6) from 6 minutes to 7 minutes: mix for 1 minute at low speed;
7) from 7 minutes to 7 minutes and 30 seconds: introduce the mixing water and
the SP whilst mixing at low speed;
8) from 7 minutes and 30 seconds to 9 minutes and 30 seconds: mix for 2
minutes at high speed (280 rpm).
The concretes studied in the present example were submitted to spread
measurements 10 minutes after mixing. The spread measurement procedure is given
herein below.
Spread measurement
The spread of the concretes was measured using a mini Abrams cone, the volume
of which was 800 ml_. The dimensions of the cone were the following:
- top diameter: 50 +/- 0.5 mm;
- bottom diameter: 100 +/- 0.5 mm;
- height: 150 +/- 0.5 mm.
The cone was placed on a plate of dried glass and filled with fresh concrete or
fresh mortar. It was then levelled. When the cone was lifted there was a slump of the
concrete or mortar on the plate of glass. The diameter of the obtained disk of concrete
or mortar was measured in millimetres +/- 5 mm. This diameter corresponded to the
spread of the concrete or mortar.
The concretes were also submitted to compressive strength measurements. The
measurement procedure is given below.
Measurement of the compressive strength
Measurement of the compressive mechanical strength was carried out on
cylindrical samples of hardened concrete with the following dimensions: diameter: 110
mm and height: 220 mm.
The samples of hardened concrete were moulded immediately after preparing the
concrete. The concrete was introduced into the mould in two equal layers. Each layer of
concrete was poured into the mould separately. A steel tamping rod (diameter: 20 mm
and height: 500 mm) was introduced in each layer of fresh concrete to manually tamp
the layer of concrete 30 times. The filled mould was levelled to remove the excess
concrete. The filled moulds were covered with a plastic cover. Then, the mould covered
with the cover was placed in a humid chamber at 20°C. The mould was removed from
the chamber and the specimen of hardened concrete was demoulded at the selected
time period for the compressive strength test, up to 24 hours after mixing.
For the time periods above 24 hours after mixing, the specimens were demoulded
24 hours after mixing, and then submerged in water at 20°C ± 1°C. The specimens of
hardened concrete were removed from the water 15 minutes maximum before the
measurement of the compressive strength. Then, the specimens of hardened concrete
were wiped and then covered with a damp cloth until the compressive strengths
measurement.
An increasing load was applied on the flat sides of the specimen of hardened
concrete to measure the compressive strength, at a speed of 2 400 N/s ± 200 N/s, until
rupture of the specimen.
Table 8 below presents the formulations and the obtained results. The figures are
expressed in kilograms for 22 litres, unless otherwise specified. Generally, the produced
concretes comprised: 280 kg/m3 of binder (clinker + mineral additions); 549 kg/m3 of
Sand 1; 279 kg/m3 of Sand 2; 298 kg/m3 of Sand 3; 737 kg/m3 of coarse aggregates;
185.4 kg/m3 of total water (including 168 kg/m3 of effective water) and 1.288 kg/m3 of
superplasticizer.
Table 8 : Formulations and results obtained for Example 7
* : concrete produced using the same cement as the other concretes in the example, but having a
higher Blaine specific surface of 5880 cm2/g
According to Table 8 herein above, the concretes according to the present
invention (Concretes 1 to 3) had better spread and compressive strengths (at 1 day and
28 days after mixing) than those of the Controls (cement + C400) and (cement + Pozz.),
and were approximately within the same order of magnitude as those of the control
cement, in particular Concrete 3.

CLAIMS
1.A hydraulic binder comprising:
25 to 60 % by mass of Portland clinker;
5 to 15 % by mass of a first mineral addition selected from:
o mineral additions reacting with at least 400 mg/g of CaO according to the
method at 90°C described in the NF P 18-513 Standard of December 30,
201 1, in Appendix A, and
o latent hydraulic materials;
a second mineral addition reacting with less than 400 mg/g of CaO according to
the method described herein above; and
either a third mineral addition with a base of calcium carbonate or calcium
sulphate, or both;
2.the hydraulic binder comprising at least 1% by mass of reactive aluminium , which
is to say that contributes to the development of strengths.
2- The hydraulic binder according to claim 1, wherein the first mineral addition is
selected from blast furnace slags, silica fume, metakaolins, biomass ash,
sedimentary pozzolans, weathered pozzolans and mixtures thereof.
3- The hydraulic binder according to claim 1 or claim 2, wherein the content of the
second mineral addition is at least 23 % by mass relative to the mass of binder.
4- The hydraulic binder according to any one of claims 1 to 3, wherein the second
mineral addition is selected from pozzolans of volcanic origin, fly ash, quartz and
mixtures thereof.
5- The hydraulic binder according to any one of claims 1 to 4, wherein the content of
the third mineral addition with a base of calcium carbonate is at most 10 %, by
mass relative to the mass of binder.
6- The hydraulic binder according to any one of claims 1 to 5, wherein the content of
calcium sulphate is from 0 to 7 % by mass relative to the mass of binder.
7- A process for production of the hydraulic binder according to any one of claims 1
to 6, comprising a step of mixing the different constituents.
A hydraulic composition comprising the hydraulic binder according to any
claims 1 to 6 and water.
A process for production of the hydraulic composition according to claim 8,
comprising a step of mixing the hydraulic binder according to any one of claims 1
to 6 with water.
An object shaped for the construction field comprising a hydraulic composition
according to claim 8.
A use of at least three different mineral additions to improve the compressive
mechanical strength of a hydraulic composition, whatever the time period beyond
2 days after mixing, said hydraulic composition comprising, by mass relative to the
mass of binder, from 25 to 60 % of Portland clinker, said at least three different
mineral additions being:
- from 5 to 15 % of a first mineral addition as described herein above;
- a second mineral addition as described in claim 1; and
- either a third mineral addition with a base of calcium carbonate or calcium
sulphate, or both.