Ettringite binder for dense mortar, comprising calcium sulphates and a mineral compound of calcium aluminates

CA 02484045 2004-10-22 WO 03/091179 PCT / FR03 / 01304 1 Ettringite binder for dense mortar, comprising calcium sulphates and an inorganic compound of calcium aluminates.

The present invention relates to an ettringite binder for mortar, in particular for dense mortar, preferably having a water / solids weight ratio of less than 0.5, said binder comprising an inorganic compound of calcium aluminates and calcium sulfate.

By ettringite binder is meant a hydraulic binder whose components lo, during hydration under normal conditions of use, give ettringite as the main hydrate, which is a calcium trisulphoaluminate corresponding to the formula 3CaO, A1203.3CaS04 .32H20.

By solids is meant all of the dry constituents of the mortar.

The invention also relates to a dry mortar formulated from this ettringite binder comprising the inorganic compound of calcium aluminates and calcium sulfate.

The invention also relates to a wet mortar obtained by 2o mixing the dry mortar as defined above, with water in an amount such that the water / solids weight ratio is less than 0.5.

The invention finally relates to the use of an inorganic compound of calcium aluminates for the formulation of an ettringite binder, of a dry mortar or of a wet mortar as defined above.

2s The ettringitic binder comprising an inorganic compound of calcium aluminates and calcium sulphate is intended for use in construction mortars and concretes for which rapid return to service of the structure is expected.

In particular, it makes it possible to constitute repair and preparation products for floors such as, for example, screeds, smoothing plasters, tile adhesives.

The rapid return to service of structures requires reaching, depending on the applications, a minimum level of mechanical resistance at a given time, and / or a recovery time defined by the residual moisture in the material.

The products which can be put back into service quickly are CA 02484045 2004-10-22 WO 03/091179 PCT / FR03 / 01304 2 conventionally constituted from a binder whose hydration leads to the formation of ettringite.

In the application of smoothing plaster for example, according to the specifications of the Scientific and Technical Center for Building s ("Products and systems for the preparation of interior floors for the laying of thin floor coverings" - Technical guide for technical advice and classification P.

CSTB Cahiers, n ° 2893 - Delivery 370 of June 1996), the products must meet both mechanical performance criteria, adhesion performance, and suitability criteria for use (homogeneity of the paste , fluidity (spreading diameter of the paste previously poured into a ring 30 mm high and 50 mm in diameter) and gelation time).

In addition to the values ​​imposed by CSTB, the rapid leveling plasters must meet at least the following criteria under normal temperature and humidity conditions - spread of 150 mm at intervals of 7 and 20 min;

- mechanical compressive strengths greater than 4 MPa at 4:00 a.m.

- 24 hour recovery time (3% residual moisture in 20 ~ the material for application thicknesses less than 10 mm);

- mechanical compressive strengths greater than 25 MPa at 28 days.

The chemical reaction of ettringite formation is as follows 2s 6Ca2 + + 2A1 (OH) 4 + 3S042 ~ + 40H '+ 26H20 ~ 3Ca0A1203.3CaS04.32H20 The solubility product of ettringite at equilibrium is: Kett = 4.9 x 30 104.

The rate of ettringite formation (rate of nucleation and growth of ettringite crystals) is dependent on several parameters, including the supersaturation coefficient (3, related to the energy available for the formation of nuclei 3s ~ 3 = ( a ~ a2 +) 6 * (aAl (OH ~ _) 2 * (aS042-) 3 * (aOH-) 4 ~ Kett CA 02484045 2004-10-22 WO 03/091179 PCT / FR03 / 01304 3 where a; represents the ion activities i.

Ettringite can be obtained by the hydration of compositions comprising calcium aluminates and a source of sulphate, and optionally s Portland cement and / or lime which bring in solution the ions necessary for carrying out this chemical reaction.

Calcium aluminates are combinations of aluminum oxide AI203, represented by A in the cement notation, and of calcium oxide CaO, represented by C in this same cement notation, these oxides being crystallized in particular in the form C3A , C12A7 and CA.

In practice today, the formulations of quick-hardening and drying mortars include a combination of calcium aluminates, calcium sulphate and Portland cement, is with proportions of each of the constituents which are difficult to define because it is necessary to be able to control the hydration in the form of ettringite, so as to achieve the best compromise between the quantity of ettringite formed which guarantees the drying capacity of the product (quantity of mixing water crystallized in the form of significant hydrates) and the morphology of this 2o ettringite, which, for a density of given crystals, guarantees the level of mechanical resistance and the control of dimensional variations throughout the hardening process until long term.

This compromise is all the more difficult to achieve since the levels of speed of acquisition of the resistances which it is desired to reach 2s must be compatible with the characteristics of expected implementation, in particular the workability maintenance time.

This compromise is not obtained satisfactorily in the mortars of the prior art.

Thus, for example, US Pat. No. 4,350,533 describes 3o ettringite cement compositions based on calcium aluminate cements, calcium sulfate, in particular in the form of gypsum, and optionally. lime fed separately and Portland cement.

However, the kinetics of the development of mechanical strengths is much lower than that sought in the context of the present invention.

CA 02484045 2004-10-22 WO 03/091179 PCT / FR03 / 01304 4 It is known, for so-called “mine packing” applications (where one seeks to fill the cavities which appear in underground structures), of use ettringite mixtures of calcium aluminates and calcium sulphate.

But the constraints of the system are very different from the “dense mortars” applications of the invention: the product must be pumpable, set quickly, but with a water / solids ratio of the order of 5 (the important point in this application. being to make a lot of volume), the mechanical compressive strengths at 24 hours do not exceed 5 MPa.

Likewise, the durability of the system is not a key criterion, nor is the dimensional variations.

The existing constraints in “dense mortar” applications are such that it is not possible to use these “mine packing” solutions directly, they must be reformulated and adapted to the constraints of dense systems.

The aim of the invention is therefore to remedy the drawbacks of the state of the art by proposing an ettringite binder comprising calcium sulphate and an inorganic compound of calcium aluminates, making it possible to achieve the best possible compromise in dense media. between the workability maintenance time and 2o kinetics of acquisition of mechanical strengths.

Another advantage of the invention is that it allows structures to be put back into service quickly, while retaining workability equivalent to that obtained with the mortars of the prior art.

For formulations containing binders having the same alumina content, the same level of binder, and an identical Blaine fineness of the calcium aluminate, the acquisition of mechanical strengths is thus much faster and the recirculation time. pedestrian is twice as short with the mortars produced with the binder according to the invention than with the mortars produced with a binder according to the prior art.

3o The invention therefore aims to provide an ettringite binder for dense mortar, said mortar preferably having at the time of mixing with water a water / solids weight ratio of less than 0.5, said binder comprising calcium sulphates and a mineral compound of calcium aluminates, the aluminates and the sulphates and their 3s concentration in the binder being such that the calcium ions CA 02484045 2004-10-22 WO 03/091179 PCT / FR03 / 01304 and aluminum respectively are released in optimal proportions simultaneously and regularly throughout the hydration process, leading to the formation of ettringite without the early blocking at the anhydrous grain-water interfaces, which interferes with the dissolution of anhydrous grains and consequently decreases the yield of ettringite formation.

In fact, the formation of ettringite results directly from the relative dissolution rates of the soluble constituents which will determine the proportions between the calcium, aluminum and sulfate ions in the solution.

The calcium ion concentration acts in the first order Io on the formation kinetics of ettringite; when it is high, the formation of ettringite can be extremely rapid, or even flash, and therefore occur instantaneously around the anhydrous phases containing the other necessary ions, that is to say the sulphates or the aluminates as the case may be.

This phenomenon of blocking reaction interfaces is particularly critical in dense media, and when there are large differences between the release rates of calcium ions from the different soluble species and / or large differences between the release rates of calcium ions. , aluminum and sulphates.

In order to obtain the desired performance for mortars, and in particular for dense mortars, it is necessary to avoid the 2o early and very rapid formation of tringite around the less soluble grains, which then prevents the normal progress of hydration and leads a dense mortar that does not meet the specifications, particularly in terms of short-term mechanical performance.

This phenomenon of blocking of the reaction interfaces is one of the reasons explaining that the solutions used in diluted medium cannot be transposed to dense media: in fact, in diluted medium, the dissolution of the various soluble phases is greatly facilitated, which decreases the probability of ettringite formation on contact with the grains.

3o In the same way, conventional ettringite binders, comprising Portland cement and / or lime, calcium sulphate and aluminous cements, do not give the best yields of hardening kinetics.

Indeed, Portland cement comprises sources of calcium of very different mineralogical nature and solubility, such as free lime, C3S, C2S, sulphates of CA 02484045 2004-10-22 WO 03/091179 PCT / FR03 / 01304 6 calcium, as well as minor species, such as alkali sulphates, extremely soluble which significantly modify the solubilization of the phases containing calcium.

This therefore does not allow a constant supply of calcium throughout the hydration process.

s With regard to lime, its too rapid dissolution limits the solubilization of the phases containing aluminates.

An excess of lime also has strong consequences on dimensional variations (very strong expansion) and on the morphology of the ettringite formed, which becomes more massive, and therefore less structuring (mechanical strengths are reduced).

Its rate of introduction into the mixture is therefore limited, which accordingly limits the production yield of ettringite for a given sulfate or aluminate content, and therefore the performance of hardening and rapid drying.

Likewise, an excess of calcium sulphate with respect to the phases containing calcium aluminates leads to the same effects as lime, that is to say to lower mechanical strengths and to strong dimensional variations.

This is partly explained by the fact that the solubilization of calcium sulphates releases large amounts of calcium in the aqueous phase.

Also, compositions comprising the 2o phases calcium aluminates and calcium sulphate in stoichiometric proportions (molar ratio of calcium sulphate / aluminum oxide A equal to 3) cannot allow the production of dense mortars with good hardening properties and controlled dimensional variability.

2s The control of the hydration of the mortar therefore requires first of all the control of the rate of calcium supply relative to the other ionic species, and in particular aluminum.

The invention therefore relates to an ettringite binder for dense mortar comprising calcium sulphates and an inorganic compound of calcium aluminates 3o, said inorganic compound of calcium aluminates comprising oxides of calcium C and aluminum A, soluble and combined. in one or more crystallized and / or amorphous mineralogical phases, in proportions such that - the useful C / A molar ratio of the mineral compound 3s of calcium aluminates is between 1.2 and 2.7;

CA 02484045 2004-10-22 WO 03/091179 PCT / FR03 / 01304 7 - the sum by weight of the useful phases (C + A) represents at least 30% of the total weight of the mineral compound.

Preferably, the weight ratio of inorganic compound of calcium aluminates / calcium sulphate is between 0.5 and 4, better still between 1.5 s and 3.

More preferably, the calcium sulphate / aluminum oxide A molar ratio in the ettringite binder is between 0.5 and 2.

According to a preferred embodiment, the useful C / A molar ratio of the inorganic compound of calcium aluminates is between 1.3 and 2.5, better still between 1.6 and 2.

Furthermore, advantageously, the calcium sulfate / aluminum oxide A molar ratio in the ettringite binder is between 0.6 and 1.8, preferably between 0.8 and 1.7.

ls The term "useful oxides C and A" means oxides C and A which, when they are dissolved, mixed with the other constituents chosen from the composition of the mortar, including calcium sulphate, give a supersaturation coefficient ~ i> 1.

The term “useful phase” is understood to mean a phase which releases useful oxides C and A 2o.

Thus, the C2AS phases, the ferrites, are not useful phases (they are called "inert phases"). Conversely, phases C12A7, C3A, glasses, C4A3 $ (where $ represents S03 in cement notation), CA, for example, are useful phases.

2s The useful C / A molar ratio of the inorganic calcium aluminate compound is therefore the molar ratio of all of the C and A oxides of the inorganic calcium aluminate compound which are found in the useful phases.

Likewise, the sum by weight of the phases (C + A) useful is the sum by weight of the phases comprising the oxides C and A and which are 3o useful phases.

The supply of calcium and aluminum ions in solution thus takes place throughout the reaction in the proportions determined by the useful C / A molar ratio of the inorganic compound of calcium aluminates.

CA 02484045 2004-10-22 WO 03/091179 PCT / FR03 / 01304 8 According to a preferred embodiment, the dense mortar comprising the ettringite binder has at the time of mixing with water a water / solids weight ratio of less than 0, 5.

The ettringite binder according to the invention makes it possible to obtain excellent ettringite formation yields and therefore good hardening kinetics without requiring, for the formulation of the mortar, a complementary source of calcium ions.

Another advantage in dispensing with this complementary source of calcium, which can be either lime or Portland cement, is that one obtains lo ~ mortar compositions that are more regular in performance on the important criteria of the application, Portland cement in particular having a very variable content of minor species, the impact of which on the formation of ettringite is decisive.

Thus, preferably, the mortars comprising the ettringite binder according to the invention do not include Portland cement or hydraulic lime.

They can nevertheless tolerate a small percentage of hydraulic lime and / or Portland cement, within a limit of 3.5% by weight relative to the total weight of the dry mortar.

According to a preferred embodiment, the sum by weight of the useful 2o phases (C + A) represents at least 50% by weight of the weight. total of the mineral compound of calcium aluminates.

The mineral compound of calcium aluminates included in the binder used to formulate the mortar can be obtained by firing materials rich in aluminum oxide A, including bauxites, and limestone, in a second oven at a temperature above 1100 ° C. It can be obtained in the form of one or more molten or sintered clinkers which can contain crystalline phases or amorphous phases or result from a mixture of different mineral compounds comprising calcium aluminates, themselves obtained by firing or not.

The furnace used can 3o be any type of furnace conventionally used for the formation of clinkers, such as reverberation furnaces, tunnel furnaces, rotary furnaces or electric, induction or electric arc furnaces.

The mineral compound of calcium aluminates may be in a crystalline mineralogical phase chosen from CA, C12A7, C3A, C4A3 $ 3s or in an amorphous phase, or in the form of a mixture of at least CA 02484045 2004-10- 22 WO 03/091179 PCT / FR03 / 01304 9 one of said crystallized mineralogical phases and of an amorphous phase.

Preferably, the mineral compound comprises at least 30% by weight of C12A7, more preferably at least 50% by weight of C12A7, better still from 50% to 85% by weight of C12A7, relative to the total weight of the mineral compound.

The mineral compound of calcium aluminates can also comprise at least one crystalline mineralogical phase chosen from C2A (1-x) Fx, C2S, C2AS, C3S and their mixtures, where F and S represent respectively Fe203 and Si02 in cement notation, and where x is an integer lo belonging to] 0; 1].

The inorganic calcium aluminate compound can be ground and can then have a Blaine specific surface area greater than or equal to 1500 cm2 / g, preferably between 2000 and 5000 cm2 / g.

Calcium sulphate suitable for the binder can be obtained from anhydrites, gypsum, hemihydrates and mixtures thereof.

The binder comprising the mineral compound of calcium aluminates according to the invention makes it possible to obtain, after addition of aggregates and additives, a dry mortar.

The dry mortar according to the invention comprises 20 - binder according to the invention: from 15% to 75% by weight relative to the total weight of the dry mortar, limestone fillers or siliceous sands: from 25 to 85% by weight relative to the weight total of the dry mortar, 2s - lime and / or Portland cement: from 0% to 3.5% by weight relative to the total weight of the dry mortar, - polymers in redispersible powder: from 0% to 8% by weight relative to total weight of dry mortar, and / or: polymers in solid-liquid dispersion: from 0% to 20% by weight relative to the total weight of the dry mortar, - rheology additives and / or setting regulator additives.

Preferably, the dry mortar according to the invention comprises - binder according to the invention: from 20% to 50% by weight relative to the total weight of the dry mortar, CA 02484045 2004-10-22 WO 03/091179 PCT / FR03 / 01304 - limestone or siliceous sands fillers: from 50 to 80% by weight relative to the total weight of the dry mortar, - lime and / or Portland cement: from 0% to 0.5% by weight relative to the total weight of the mortar dry, s - redispersible powder polymers: from 0% to 5% by weight relative to the total weight of the dry mortar, and / or: polymers in solid-liquid dispersion: from 0% to 15% by weight relative to the total weight of the dry mortar, - rheology additives and / or setting regulator additives.

The powdered polymers can be chosen from copolymers of vinyl acetate, vinyl versatates and ethylene, available for example from the companies Wacker or Elotex, and polyvinyl alcohols.

The polymers in solid-liquid dispersion can be chosen from styrene-butadiene, acrylic styrene, acrylic, vinyl acetates and vinyl and ethylene versatate dispersions, available for example from the company Rohm & Haas.

The rheology additives are conventional constituents of 2o mortars which aim to improve the initial rheology of the mixed mortar.

Among these rheology additives, mention may be made of casein, sulfonated formaldehyde melamines, polyoxyethylene phosphonates (POE), polyethylene oxide (PCP) polycarbonates, and mixtures thereof.

These additives are commercially available products. By way of example, mention may be made of the products OPTIMA 100 ~ and PREMIA 150 °, marketed by the company CHRYSO, or MELMENT F10 ~, MELFLUX PP100F ~ marketed by the company SKW.

The rheology additives preferably represent from 0.1 to 0.5% of the total weight of the dry mortar.

They are often associated with water-soluble polymers, the function of which is to limit segregation, such as cellulose ethers, but also welan gums and polysaccharides.

The setting regulating additives can be 3s setting accelerators or setting retarders.

They preferably represent 0.1 to 0.5% of the total weight of the dry mortar from CA 02484045 2004-10-22 WO 03/091179 PCT / FR03 / 01304 11.

Preferably, tartaric acid can be used in combination with sodium gluconate as a setting retarder.

The dry mortar according to the invention makes it possible to obtain, by mixing s with water, a wet mortar.

Preferably, the amount of water is such that the water / solids weight ratio is less than 0.5.

A subject of the invention is also the use of an inorganic compound of calcium aluminates for the formulation of an ettringite binder according to the invention.

A subject of the invention is also the use of an inorganic compound of calcium aluminates for the formulation of a dry mortar according to the invention.

Finally, a subject of the invention is the use of an inorganic compound of calcium aluminates for the formulation of a wet mortar according to the invention.

The invention is illustrated and detailed by the following examples.

In all the examples, the useful C / A ratio is a molar ratio; the useful percentage (C + A) is expressed by weight relative to the total weight of the inorganic compound; the calcium sulfate / Al2O3 ratio is a 2o molar ratio; the ~ quantity of mixing water is given as a percentage by weight relative to the total weight of the dry constituents of the mortar.

Example 1- Comparisons 2,3,4,5 2s A mortar according to the invention is produced, comprising a binder according to the invention (test No. 1). By way of comparison, mortars are produced from binders belonging to the state of the art (tests No. 2,3,4,5).

Table 1 shows the composition of the binders.

CA 02484045 2004-10-22 WO 03/091179 PCT / FR03 / 01304 12 Table 1 N test 1 2 3 4 5 Mineral compound of calcium aluminates (SSB = 3000 cm2 / g) - C / A useful 1.77 1 1 1 1 - (C + A) useful (%) 87 55. 55 55 55 - majority phases C12 CA CA CA CA - quantity (% by weight) A7 54 65 63 63 65 Calcium sulphate * (% by weight) 35 36 35 33.5 33.5 Calcium sulphate / AI203 (ratio 0.85 - - - molar) Additional source of calcium ions - natural ** - quantity (% by weight) - P / C - CP - 5 - 3.5 3.5 / 5 * Calcium sulphate: 95% hemihydrate of purity s ** P = Portland cement CEM I 52.5 CP2; C = Lime Table 2 shows the composition of the mortars comprising the binders from Table 1.

Table 2 AFNOR 1350 Sand Binder 675 Sodium Gluconate 2.025 Li2CO3 2.025 Water 270g Table 3 shows the rheological and mechanical characteristics of the mortars obtained.

CA 02484045 2004-10-22 WO 03/091179 PCT / FR03 / 01304 13 Table 3 N Test 1 2 3 4 5 PD * Vicat 20 min 12 min 45 45 min 50 min min Rc ** 3h (MPa) 30 4.0 5 2 8.5 Rc 24h (Mpa) 46 3.5 28 2 31.5 Rc 28d (Mpa) 60 11.5 47.5 15.5 50 Observations RAS Cracks 28 days RAS RAS RAS * DP Vicat: start of setting measured according to the "Vicat" method s ** Rc - Compressive strengths, measured on specimens of dimension 4x4x16cm.

These tests show that the mortars according to the invention have very good short-term mechanical compressive strengths, while having a sufficiently long setting time which can be adjusted by the choice of the retarder dosage.

It can also be seen that the mortars according to the prior art, comprising usual aluminous cements (majority CA phase) and an additional contribution of Portland cement and / or lime, do not make it possible, for equivalent setting times, to obtain satisfactory short-term mechanical strengths (4 to 8 MPa, to be compared with 30 MPa for the mortar according to the invention).

Likewise, in certain cases in the presence of lime, the long-term resistance remains at a very low level.

2o Example 6 - Comparisons 7, 8 A mortar according to the invention is produced with a binder according to the invention (No. 6), and two mortars of the prior art, for comparison, made with a binder of the prior art (No. 7, 8), Zs The compositions of the mortars and their rheological and mechanical characteristics are shown in Table 4.

CA 02484045 2004-10-22 WO 03/091179 PCT / FR03 / 01304 14 Table 4 N Test 6 7 8 Mineral compound of calcium aluminates (SSB: 3000cmz / g) 1.77 1 1 - C / A useful - (C + A) useful (%) 87 70 70 - majority phases C12A7 CA CA uantit% by weight 19 22.5 19 Calcium sulphate (% by weight) 11 7.5 11 Calcium Sulphate / Al203 (0.92 - molar ratio) Slag (% by weight) 20 20 20 Silica sand (% by weight) 47.25 47.25 47.25 RE523Z (% by weight) 2 2 2 Lifetech 115 (% by weight) 0.1 0.1 0.1 Trisodium citrate (% by weight) 0.1 0.1 0.1 Melment F10 (% by weight) 0.3 0.3 0.3 Sodium Gluconate (% by weight) 0.05 0.05 0.05 MT400PFV (% by weight) weight) 0.05 0.05 0.05 Dehydran 1922 (% by weight) 0.15 0.15 0.15 Water 20 20 20 DP Vicat (min) 105 60 65 Rc 4h (MPa) 14.5 9.5 11 Rc 24h (MPa) 25.5 20.5 21 Rc 7 days (MPa) 41 28.5 28.5 Shrinkage 7 days (mm / m) -0.6 -1.6 -1.05 Ettringite form 7 days (J / g) 135 70 110 Residual anhydrite 7 days 315 280 500 Calcium sulphate is anhydrite at 95% purity.

s The slag is a blast furnace slag.

The siliceous sand comes from the company Sifraco, it is marketed under the name Sable NE14, its particle size is less than 500Nm (d50 = 210 μm).

RE523Z is a resin marketed by the Wacker company.

lo It is a copolymer of vinyl acetate and ethylene.

CA 02484045 2004-10-22 WO 03/091179 PCT / FR03 / 01304 Lifetech 115: it is lithium carbonate, marketed by FMC.

Melment F10: sulfonated formaldehyde melamine marketed by SKW.

s Sodium gluconate: marketed by Roquettes Frères.

MT400PFV: cellulose ether marketed by Wolf Walsrode.

Dehydran 1922: antifoam marketed by Rhodia.

The amount of residual anhydrite (given in an arbitrary unit) is measured by the height of the peak obtained by X-diffraction.

The amount of ettringite formed is measured by the heat flow released in DSC (Differential Scanning Calorimetry).

The shrinkage is measured at 7 days, on 2 × 2 × 16 cm test pieces stored at 20 ° C. and 50% relative humidity.

The mechanical strengths are measured on 2 is × 2 × 16 cm test pieces, stored at 20 ° C. and 70% hygrometry.

It can be seen that the inorganic calcium aluminate compound according to the invention makes it possible to obtain a much better compromise in performance - the kinetics of acquisition of mechanical strengths are 2o much better than with mortars formulated with mineral compounds of the prior art, - the control of dimensional variations is also better, - there is a better yield of ettringite formation as evidenced by the larger amount of ettringite formed, and the least amount of residual anhydrite.

Examples 9. 10 and comparative 11 3o Repair mortars according to the invention are produced (Tests 9 and 10), and a comparative mortar of the prior art (test 11).

Their compositions are given in Table 5.

CA 02484045 2004-10-22 WO 03/091179 PCT / FR03 / 01304 16 Table 5 N Test 9 10 11 Mineral compound of calcium aluminates (SSB: 3000cmZ / g) - C / A useful 1.77 1.77 1 - (C + A) useful (%) 87 87 70 - majority phases C12A7 C12A7 CA - quantity (% by weight) 28 30 33 Calcium sulphate (%) by weight) 15 13 10 Calcium sulphate / A1203 (ratio 0.85 0.69 molar) Silica sand Palvadeau 0 - 315pm19 19 19 (% by weight) Silica sand Palvadeau 315Nm 19 19 19 - 1 mm (% by weight) Sand siliceous Palvadeau 1- 4 mm 19 19 19 (% by weight) Sodium gluconate (% by weight) 0.1 0.1 0.1 Tartaric acid (% by weight) - 0.15 Li2CO3 (% by weight) 0.1 0.05 0.1 TOTAL 100 100 100 Water 17.2 17.2 17.2 Calcium sulphate: hemihydrate at 95% purity The rheological and mechanical characteristics of the mortar are given in Table 6.

CA 02484045 2004-10-22 WO 03/091179 PCT / FR03 / 01304 17 Table 6 N Test 9 10 11 DP Vicat 15 min 48 min 35 min FP Vicat 22 min 62 min 45 min Rc 4h (MPa) 37 33 14 Rc 24h (MPa) 51 45 40 Rc 28j (MPa) 61 52 55 FP Vicat: End of Vicat setting s The mechanical strengths are measured on 4 x 4 x 16 cm specimens, stored at 20 ° C and 70% hygrometry.

It can be seen that the mortars according to the invention have much better kinetics of resistance acquisition (resistances at 4 hours) and this for equivalent setting times.

lo Example 12 An adhesive mortar according to the invention is produced.

Its composition is given in Table 7.

is CA 02484045 2004-10-22 WO 03/091179 PCT / FR03 / 01304 18 Table 7 N Test 12 Composite of calcium aluminates (SSB 1.77 3000cm2 / g) - C / A useful 87 - (C + A) useful (%) C12A7 - majority phases 26.5 - quantity (% by weight) Calcium sulphate (% by weight) 13.5 Calcium sulphate / Al203 (0.81 molar ratio) Durcal 15 (% by weight) 9 Sand siliceous Sifraco NE14 (% 48.65 by weight) RE530Z (% by weight) 1.5 Tylose MH3001 P6 (% by weight) 0.35 Trisodium citrate (% by weight) 0.2 Sodium bicarbonate (% by weight) weight) 0.2 Li2CO3 (wt%) 0.1.

TOTAL 100 Water 25.5 Calcium sulphate: hemihydrate at 95% purity s Durcal 15: calcium carbonate marketed by OMYA having a grain size d50 of 15 μm, with 1% of the grains having a size greater than 100 μm .

RE530Z is a resin marketed by the Wacker company.

It is a copolymer of vinyl acetate and ethylene.

io Tylose MH3001 P6: cellulose ether marketed by Clariant.

The mechanical properties are shown in Table 8.

CA 02484045 2004-10-22 WO 03/091179 PCT / FR03 / 01304 19 Table 8 N Test 12 Open time over 20 min Vicat DP slab 45 min Adhrence 4h (MPa) 0.5 Adhrence 24h (MPa) 1.2 Adhrence 28d (MPa) 2.1 s The adhesion is measured with a SATTEC dynamometer according to the operating mode described in the Technical Specifications Booklet "Interior and exterior floor coverings in ceramic tiles or the like glued using adhesive mortars" Notebooks of CSTB 3267.

A product is obtained with an open time of 20 minutes and good mechanical properties.

Example 13 A rapid fluid screed is produced with an inorganic calcium aluminate compound according to the invention and gypsum (test 13).

The composition and the rheological and mechanical results are collated in Table 9.

CA 02484045 2004-10-22 WO 03/091179 PCT / FR03 / 01304 Table 9 N Test 13 Composite of calcium aluminates (SSB = 1.77 2010 cm2 / g) - Useful C / A 87 - (C + A) useful (%) C12A7 - majority phases 14.3 - quantity (% by weight) Calcium sulphate (% by weight) 7.2 Calcium sulphate / Al203 (0.80 molar ratio) Additional source of calcium ions - nature C - quantity (% by weight) 0.2 Silica sand 1- 4 mm (% by weight) 49.4 Silica sand 0 - 315 Nm (% in 15.3 weight) E10 (% by weight) 8.0 D130 (% in weight) 3.9 RE523Z (% by weight) 1 Dehydran 1922 (% by weight) 0.1 Cellulose ether (% by weight) 0.07 Li2CO3 (% by weight) 0.05 Casine (% by weight) 0.3 K2S04 (% by weight) 0.2 Sodium gluconate (% by weight) 0.06 Tartaric Acid (% by weight) 0.12 TOTAL 100 Water 14 Auto Spread 7 min (mm) 260 Auto Spread 20 min (mm) 260 Time open (min) 95 DP Vicat (min) 115 FP Vicat (min) 145 Rc 5h (MPa) 15.8 Rc 24h (MPa) 20.3 CA 02484045 2004-10-22 WO 03/091179 PCT / FR03 / 01304 21 VS : Lime, marketed by Balthazar & Cotte Calcium sulphate: gypsum at 95% purity Siliceous sand: Palvadeau E10 sand: Sifraco siliceous sand with grain size d50 = 21 Nm.

s D130: Durcal 130, limestone marketed by OMYA, 76% of the grains having a size greater than 100 Nm, and 0.2% of the grains having a size less than 500 μm.

Casein: marketed by Unilait.

Self-spreading is measured with an ASTM ~ o frustoconical cone (described in ASTM C230).

The open time corresponds to the time after which the dough has lost its ability to flow by itself.

The mechanical strengths are measured on 4 x 4 x 16 cm test pieces, stored at 20 ° C. and 70% hygrometry.

is The rheological properties (spreading) of the screed are good, and even with a very long open time (1 h 30), the hardening kinetics remain very fast, despite the absence of Portland cement and ~ Ine low specific surface Blaine of the mineral compound of calcium aluminates according to the invention.

Examples 14, 15 - Comparisons 16, 17, 18 and 19 Smoothing coatings are produced with inorganic compounds of calcium aluminates and of calcium sulphate according to the invention (tests 2s 14, 15) which are compared with control mixtures based on inorganic calcium aluminate compounds of the prior art and Portland cement (tests 16, 17, 18, 19).

The compositions are collated in Table 10.

To facilitate the comparison of the performance between the mortars 3o of the prior art and the mortars of the invention, the total amount, by weight, of alumina in the binder is shown in Table 10.

CA 02484045 2004-10-22 WO 03/091179 PCT / FR03 / 01304 22 Table 10 Invention Prior art N Test 14 15 16 17 18 19 Composite of aluminates of 1.77 1.77 1 1 1 1 calcium (SSB: 3000cm2 / g) - C / A useful 87 87 55 70 55 70 - (C + A) useful (%) C12A7 C12A7 CA CA CA CA CA - majority phases 18 17 20 20 20 20 - quantity (% by weight) Additional source d 'ions - CPPP / CP / C calcium - 0.4 4 4 6 / 0.2 6 / 0.2 - nature - amount (% by weight) of total alumina 7.4 7 8 10.6 8.1 10 , 7 Calcium sulphate (% 9 7 7 7 7 7 by weight) Sulphate of 0.79 0.65 - - - Calcium / Al203 (molar ratio) Durcal 15 (% by weight) 23 27 19 19 18 18 Durcal 130 ( % by weight) 9 10 9 9 10 10 NE14 (% by weight) 37.8 36 37.8 37.8 36 36 RE523Z (% by weight) 2 2.5 2 2 2.5 2.5 Li2C03 (% by weight) 0.05 0.05 0.1 0.1 0.05 0.05 Citric acid (% in - - 0.02 0.02 - weight) Tartaric acid (% in 0.075 0.1 0 0 0.07 0.07 by weight) Melflux PP100F (% in 0.2 - 0.2 0.2 - weight) Cellulose ether MT400PFV0.06 0.06 0.05 0.07 0.06 0.06 (% by weight) Dehydran 1922 (% in 0.1 0.1 0.1 0.1 0.1 0 , 1 weight) K2S04 (% by weight) - 0.2 - - 0.2 0.2 Casin (% by weight) - 0.4 - - 0.4 0.4 Sodium gluconate - 0.06 - - 0 0.03 0.03 (wt%) Water 24 24 24 24 24 24 CA 02484045 2004-10-22 WO 03/091179 PCT / FR03 / 01304 23 Calcium sulphate: hemihydrate at 95% purity.

P: Portland cement CPA CEM I 52.5 CP2; C = Lime.

Durcal 15: limestone marketed by OMYA.

Durcal 130: limestone marketed by OMYA.

s The mechanical and rheological properties are collated in Table 11.

Table 11 Invention Prior Art N Test 14 15 16 17 18 19 Self-spreading 7 min 144 148 150 151 143 149 (mm) Self-spreading 20 145 146 150 120 145 144 min (mm) Sliding time 29 42 30 26 50 45 (min) DP Vicat (min) 35 55 80 35 120 95 FP Vicat (min) 40 65 90 40 140 120 Recirculation '1 h 30 1 h 30 3 h 2 h 30 3 h 3 h Rc 2 h (MPa) 5 10 1.5 3 1 0 , 5 Rc 4h (MPa) 17.5 12.5 4 7.5 6.5 6.5 Rc 24h (MPa) 24.5 18 18 24 15.5 17.5 Rc 28j (MPa) 38 29 28 35 28 , 5 29 Debt collection period 212h 12h 24h 24h 24h 24h Ettringite 4h3 - 140 - - 100 110 Ettringite 24h4 - 160 - - 140 150 Adhrences - 2.8 - - 2.3 Withdrawals - 0.8 - - 1 1.

Recirculation: time after which the mechanical resistance in compression of the smoothing coating reaches 3Mpa.

io 2. Recovery time: time after which the smoothing plaster exhibits residual moisture (measured according to the calcium carbide method (release of acetylene by contacting the moisture of the material) using the CM Tester from Riedel & Haën) less than 3%, measured in thickness of 9mm on a concrete slab at 23 ° C and is 50% hygrometry.

CA 02484045 2004-10-22 WO 03/091179 PCT / FR03 / 01304 24 3.

Ettringite 4h: Quantity of mixing water crystallized in the form of ettringite, in g / kg of formulated product, at t = 4h00, measured according to the calcium carbide method (release of acetylene by contact with humidity material) using Riedel's CM Tester &

s Haën.

4.

Ettringite 24 h: Quantity of mixing water crystallized in the form of ettringite, in g / kg of formulated product, at t = 24 h.

5.

Adhesion: measured with a Sattec dynanometer according to the operating protocol described in the technical guide for the io technical opinion and the P classification.

CSTB notebooks , n ° 2893, on concrete support at 28 days, without bonding primer, in Mpa.

6.

Shrinkage: drying shrinkage, measured at 28 days, on 2x2x16cm specimens, stored at 20 ° C - 70% relative humidity, in mm / m.

The gelation time and the self-spreading are measured according to the operating protocol described in the technical guide for the technical opinion and the classification P.

CSTB Notebooks, n ° 2893.

The mechanical strengths are measured on 2 x 2 x 16 cm test pieces, stored at 20 ° C. and 70% hygrometry.

FIG. 1 shows the thermal flux curves of tests 15 20 (curve 2) according to the invention and 18 (curve 1) according to the prior art, obtained by isothermal microcalorimetry.

The amount of ettringite formed in the short term is visualized by the heat flow released by the reaction.

The rheological properties (spreading) are good with the 2s smoothing coatings of the invention and those of the prior art, but the mechanical properties (compressive strength) are markedly improved with the binder according to the invention.

As illustrated in Figure 1, ettringite is formed in the mortar formulated with the binder of the invention, in a much shorter time 3o than with the mortar formulated with the binder according to the prior art and in a single step, unlike the mortar formulated with the binder according to the prior art.

In addition, the mineral compound of calcium aluminates according to the invention allows, without additional addition of portland cement in CA 02484045 2004-10-22 WO 03/091179 PCT / FR03 / 01304 the binder and with a total alumina content in the weaker composition, to have a return time twice as fast.

Finally, the performance over time, whether in terms of drying shrinkage, compressive strength or adhesion to the substrate, is also at a higher level.

Examples 20, 21 and 22 Three clinkers (A, B and C) according to the invention, of different mineralogy, are produced.

Clinkers A and B are made by melting from bauxite and limestone in a refractory crucible at a temperature of 1400 ° C.

Clinker C is made by sintering from bauxite, limestone and anhydrite in a refractory crucible at a temperature of 1300 ° C is for 2 hours.

The mineralogical compositions (expressed as a percentage by weight relative to the total weight of the clinker) of these clinkers are given in Table 12 below 2o Table 12 ABC Useful phases CA 5 C12A7 45 65 45 C3A 5 C4A3 $ 40 Phases 50 30 15 inert SSB 3010 2000 2900 C / A useful 1.61 1.8 1.53 C + A useful 50% 70% 85 The composition of the mortars obtained from these clinkers and their mechanical and rheological characteristics are grouped together in Table 13.

CA 02484045 2004-10-22 WO 03/091179 PCT / FR03 / 01304 26 Table 13 N Test 20 21 22 Calcium aluminate compound 20 20 20 (% by weight) Calcium sulphate (% by weight) 9 9 7 Sulphate Calcium / Al203 (ratio 1.21 0.91 0.73 molar) Durcal 15 (% by weight) 22 22 24 Durcal 130 (% by weight) 8 8 8 NE14 (% by weight) 38.6 38.6 38, 6 RE523Z (% by weight) 2 2 2 Li2C03 (% by weight) 0.05 0.05 0.05 Tartaric acid (% by weight) 0.06 0.04 0.05 Melflux PP100F (% by weight) 0, 15 0.1 0.15 Cellulose ether MT400PFV 0.06 0.06 0.06 (% by weight) Dehydran 1922 (% by weight) 0.08 0.08 0.08 Water 24% 24% 24% Self-spreading 7 min (mm) 150 148 148 Self-spreading 20 min (mm) 138 144 140 Gliding time (min) 23 30 35 DP Vicat (min) 32 40 42 FP Vicat (min) 35 55 52 Rc 2h (MPa) 3.5 5 3 Rc 4h (MPa) 4.5 7 10.5 Rc 24h (MPa) 17 17.5 20.5 Rc 28j (MPa) 26.5 22.5 30.5 Calcium sulphate: hemihydrate at 95% purity The mechanical strengths are measured on 2 x 2 x 10 cm test pieces, stored at 20 ° C. and 70% hygrometry.

The binders according to the invention make it possible to obtain mortars having good compromises in both rheological and mechanical behavior.