BE1022191B1 - CEMENT MATERIAL FOR GROUT, MORTAR OR LIGHT CONCRETE, CEMENTITIOUS COMPOSITIONS INCLUDING SUCH A MATRIX AND THEIR USES FOR STRUCTURAL LIGHT MIXTURES - Google Patents

Abstract

Cementitious matrix comprising, in the fresh state, a cement of Blaine fineness less than 6000 cm2 / g, at least one pozzolanic addition, effective water, characterized in that it has an Eeff / L ratio of between approximately 0 , 4 and 0.7, in particular between 0.45 and 10 0.65, preferably between 0.5 and 0.6 and an Add / L ratio between 0.40 and 0.70, in particular between 0, 50 and 0.70, preferably between 0.55 and 0.65, where Eeff represents the volume in liters of effective water used in the cement matrix, Add represents the mass, in kg, of pozzolanic addition contained in said matrix, and L represents the total mass, in kg, of cement and pozzolanic addition contained in said matrix. The invention also relates to the grout, mortar and concrete compositions produced from said cementitious matrix and their uses for mortars or lightweight structural concretes.

Description

CEMENTITIOUS MATRIX FOR COULIS. MORTAR OR LIGHT CONCRETE. The present invention relates to the field of cementitious matrices, and more particularly to cementitious matrices intended for the production of grout compositions, mortars and lightweight concretes, as well as cementitious matrices for the production of grout compositions, mortars and lightweight concretes, and their use as self-placing concrete mortar and / or as mortar or structural concrete:

For several years, for better insulation of buildings, we seek to produce concretes or mortars with low thermal conductivity. However, this improvement in the thermal properties of the material must not be at the expense of their mechanical strength. Those skilled in the art know from European Patent EP2203400 concrete compositions containing air-entraining admixtures (a significant air content to increase the thermal insulating performance) and containing lightweight aggregates, such as pumice stones, clays. or expanded shales having a high porosity which gives the material an insulating character.

The French patent application FR 2 983 472 describes compositions of concrete or lightweight structural mortars based on a combination of lightweight aggregates with a cement matrix containing a significant content of effective water. Indeed, it has been found that a high effective water content makes it possible to reduce the density of the cement matrix and consequently its rigidity, and also contributes to reducing the difference in rigidity between the matrix and the light aggregates. Thus is obtained a more elastically homogeneous concrete, which may have a compressive strength greater than 25 MPa at 28 days. .

A compressive strength value greater than 25 MPa at 28 days corresponds, traditionally, to a concrete called structural concrete, or structural concrete.

However, these compositions are not interested in the thermal performance of the cement matrix.

The object of the present invention is to propose a cementitious matrix intrinsically having lightness properties, that is to say a low density, and thermal insulation properties, making it possible to obtain either a grout having, at least one dry state, low conductivity. thermal. either a light mortar or a light concrete, said mortar or said concrete having a dry density of less than 1500 kg / m3 and a low thermal conductivity. Low thermal conductivity here means a thermal conductivity of less than 0.6 W / m. K about. '

By cement matrix is meant a mixture based on binder (cement and pozzolanic additions) water and optionally adjuvants, that is to say without granulate, especially without fillers, fine aggregates or coarse aggregates.

Another object of the invention is to provide a cementitious matrix for producing a concrete composition or light mortar that can be used respectively as self-placing concrete or mortar, that is to say having a very fluid consistency. .

Another object of the invention is to provide a cementitious matrix for producing a concrete composition or structural mortar. For this purpose, the present invention relates to a cementitious matrix comprising, in the fresh state, a Blaine fineness cement of less than 6000 cm 2 / g, at least one pozzolanic addition and effective water, characterized in that it has An Eeff / L ratio of between approximately 0.4 and 0.7, in particular between 0.45 and 0.65, preferably between 0.5 and 0.6 and an Add / L ratio of between 0, 40 and 0.70, in particular between 0.50 and 0.70, preferably between 0.55 and 0.65, the ratio Add / L being between 0.60 and 0.70 when the addition pozzolanique comprises a blast-furnace slag, where Eeff represents the volume in liters of effective water implemented in the cement matrix, Add represents the weight, in kg, of pozzolanic addition contained in said matrix, and L represents the total mass in kg of cement and pozzolanic addition contained in said matrix.

"Effective water" means the internal water between the grains of the solid skeleton formed by the cement and the additions for a cement matrix, and the cement, additions and aggregates of a grout, mortar or concrete composition. . Effective water therefore represents the water necessary for the hydration of the binder and the obtaining of the consistency. This is the total water added to the solid constituents of the cement matrix or the grout composition, concrete or mortar, from which the water absorbed by the aggregates is subtracted. The water absorption of the aggregates is determined by an immersion test for 24 hours of an initially dry granulate.

By "pozzolanic addition" is meant a material, mineral or of organic origin, less than 100 microns in size, having a pozzolanic activity. The mineral pozzolanic additions may be selected from the list comprising: fly ash, blast furnace slag, silica fume, metakaolin, zeolite or a combination thereof.

By "pozzolanic addition of organic origin" is meant an addition which results from the incineration of organic matter, generally waste from biomass, and which has a silica content greater than 80%, preferably greater than 90%. , a density of less than 2.5 g / cm3, preferably less than 2.25 g / cm3 and a size of less than 50 pm, preferably less than 25 pm. Such a pozzolanic addition of organic origin may be chosen especially from the list comprising: the ashes of rice husk, the ashes of rice straw, or be a combination thereof.

The thermal conductivity of a cementitious matrix generally varies proportionally to its density. The more the cement matrix is porous and the more its density in the fresh state, and also in the cured state after setting and drying, decreases. The porosities are at the origin of the low density of the dry cement matrix and its thermal insulating properties.

The present invention can thus be considered as an improvement of the preceding techniques. By a selection of the constituents of the cement matrix, and their relative proportions, and in particular Eeff / L and Add / L ratios as defined above, the applicant has found that it is possible to improve the thermal insulating properties. materials ..cimen.tair.es all.en maintaining their mechanical strength.

By "improving the insulating properties" is meant a cementitious matrix whose thermal conductivity is less than 0.6 W / mK, especially less than 0.55 W / mK, preferably less than 0.5 W / mK, more preferably lower. at 0.45 W / m. K.

By "preserving the mechanical strength" is meant a cement matrix whose compressive strength, in the dry state, is at least 20 MPa after 28 days, preferably at least 25 MPa after 28 days and preferably another 30 MPa after 28 days.

By "cement" is meant a cement based on Portland clinker, such as CEM cements I, II, III, IV, and V, in particular a cement CEM I or II, preferably a cement CEM I.

Advantageously, the total Portland clinker mass is at least greater than 150 kg per cubic meter of said cement matrix, in particular at least greater than 200 kg per cubic meter, preferably at least greater than 250 kg per cubic meter, more preferably at least greater than 280 kg per cubic meter. m3.

Blaine fineness, or Blaine specific surface area, of cement is determined according to the air permeability method according to the NF EN 196-6 standard. The higher the Blaine fineness, the more the cement is reactive, however a cement of great fineness implies an additional cost (energy consumption, grinding time) which is not desirable in the context of the present invention.

The cement used in the present cementitious matrix advantageously has a Blaine fineness of less than 5000 cm 2 / g, preferably less than 4500 cm 2 / g.

According to a first variant of the invention, pozzolanic addition in the sense of the present invention may be a combination of one or more mineral additions and one or more additions of organic origin. .

In the case of such a combination of additions, the mineral additions represent about 50 to 95%, preferably 75 to 95%, of the total weight of the pozzolanic addition (mineral and of organic origin).

According to a second variant of the invention, pozzolanic addition within the meaning of the present invention consists entirely of one or more mineral additions.

Advantageously, the inorganic pozzolanic addition is chosen from fly ash, silica fumes, zeolites, metakaolin, and a combination of several of these additions, especially from combinations of fly ash and silica fumes, ash. flakes and zeolites, blast furnace slag and fly ash, metakaolin and blast furnace slag, metakaolin and fly ash, metakaolin and silica fumes, metakaolin and zeolites, blast furnace slag and silica fumes.

Very advantageously the mineral pozzolanic addition is a combination of fly ash and silica fumes, and the mass ratio of fly ash on silica fume is less than 10, especially less than 5, preferably less than 4.

Most advantageously, the mineral pozzolanic addition is a blast furnace slag or a combination of blast furnace slag and fly ash or a combination of metakaolin and blast furnace slag. In this case, when the pozzolanic addition comprises a blast furnace slag, the Add / L ratio is between 0.60 and 0.70.

According to a third variant of the invention, pozzolanic addition within the meaning of the present invention consists entirely of one or more additions of organic origins.

Advantageously, the mass of said pozzolanic addition is at least greater than 60 kg per cubic meter of said cement matrix, in particular at least greater than 80 kg per cubic meter, preferably at least greater than 100 kg per cubic meter, more preferably at least greater than 120 kg per cubic meter. m3.

Advantageously, the cementitious matrix according to the present invention comprises at least one viscosing agent.

"Viscosant Part" means a compound for increasing the viscosity of a fresh cementitious matrix Advantageously, the viscosing agent is chosen from cellulose ethers, in particular polysaccharides, hydroxyalkylcelluloses, hydroxyethylcelluloses, methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, ethylhydroxyethylcellulose, poly (ethylene oxides), polyvinyl alcohols, polyamides, or a mixture thereof.

Advantageously, the viscosifying agent is a hydroxyalkylcellulose, preferably a hydrophobic, non-modified hydroxyethylcellulose, preferably the viscosifying agent is a formulation comprising hydroxyethylcellulose, iattapulgite and a siliceous filler in an aqueous K 2 CO 3 solution.

In particular, the proportion of viscosifying agent represents between 0.05 and 3.0% of the total mass of the cement and the additions, particularly between 0.3 and 2.0% of the total mass of the cement and the additions, preferably between 0.degree. , 3 and 1.0% of the total mass of cement and additions.

Preferably, the cementitious matrix according to the present invention does not comprise an air entrainer, foaming agent, or other surfactant compound having the effect of causing air in the fresh matrix, or of metals capable of reacting with water to form gas bubbles (eg aluminum).

It is nevertheless important to note that any concrete or mortar, because of the simple kneading of the mix, contains small proportions of entrained air, generally less than 5% by volume.

By "superplasticizer" is meant a compound for increasing the fluidity of a cement matrix, a grout, a mortar or a concrete, in the fresh state, without the need to increase the volume of 'water. Superplasticizers generally act by deflocculation of the binder particles.

According to a first variant, the cementitious matrix according to the present invention does not contain a superplasticizer agent.

According to a second variant, the cementitious matrix according to the present invention contains a superplasticizing agent. In this case, the superplasticizing agent may be chosen from polynaphthalenesulphonates, polymelaminesulphonates, lignosulphonates and polycarboxylates, preferably a polycarboxylate derivative with polyethylene oxide side chains.

Advantageously, the superplasticizer content is less than 2.5% by weight of the cement, preferably between 0.3% and 2.5% by weight of the cement, more preferably between 0.3 and 1% by weight of the cement. .

Advantageously, the cementitious matrix according to the present invention has a real density in the fresh state of between 1300 and 2000 kg / m 3, in particular between 1400 and 1900 kg / m 3, preferably between 1500 and 1800 kg / m 3.

By "fresh state" means the moment or the cement matrix, or the cementitious composition containing the cement matrix according to the invention, such as a slurry; a mortar or concrete, contains all its final components, has just been mixed, but has not yet begun to set.

Advantageously, the cementitious matrix according to the present invention, that is to say without fillers, nor. fine aggregates or coarse aggregates, has a density in the dry state of less than 1500 kg / m3, especially less than 1450 kg / m3, preferably less than 1400 kg / m3.

By "dry state" is meant the moment when the mass of the sample hardly varies after passing through an oven at about 105 ° C. In this case, "almost more" means a maximum variation of the order of 0.05%.

Grouts, mortars and concretes differ from one another by the size of aggregates incorporated in the cement matrix.

As a result of the properties of the cementitious matrix according to the invention, a cementitious composition containing said cementitious matrix, in the form of a grout, a mortar or a concrete, has a real density in the dry state of between 1000 and 1800 kg / m3, especially between 1100 and 1700 kg / m3, preferably between 1200 and 1600 kg / m3.

"Fine aggregates" means aggregates whose particle size is greater than or equal to 150 μm and less than or equal to 4 mm.

"Coarse aggregates" means aggregates whose particle size is greater than 4 mm, particularly the size of coarse aggregates may be less than or equal to 20 mm.

By "filler" means aggregates having no pozzolanic properties and whose particle size is greater than 0 pm, especially greater than 1 pm, and is less than 150 pm.

The present invention also relates to a cementitious composition characterized in that it contains a cement matrix as defined above and fillers whose particle size is between 0 and 0.15 mm. Such a cementitious composition, when it does not contain fine aggregates or coarse aggregates and only fillers is called "grout".

The present invention also relates to a cementitious composition characterized in that it contains a cement matrix as defined above, fine aggregates whose particle size is between 0.15 mm and 4 mm, possibly fillers, and not does not contain coarse granules. ' Such a composition is referred to as a "mortar." Preferably in this mortar composition, the mass of the fine granulates is at least greater than 250 kg per m 3 of said composition, in particular at least greater than 300 kg per m 3, preferably at least greater than at 350 kg per m3, more preferably at least greater than 375 kg per m3.

The present invention also relates to a cementitious composition characterized in that it contains a cement matrix as defined above, fine aggregates whose particle size is between 0.15 mm and 4 mm and coarse aggregates whose particle size is greater than 4 mm, and possibly fillers. Such a composition is called "concrete". Preferably in this concrete composition the total mass of fine and coarse aggregates is at least greater than 550 kg per m 3 of said composition,. in particular at least greater than 600 kg per cubic meter, preferably at least greater than 650 kg per cubic meter, more preferably at least greater than 675 kg per cubic meter.

Advantageously, the minimum effective water volume is at least 180 liters per cubic meter of cementitious composition, especially at least 200 liters, preferably at least 220 liters, more preferably at least 240 liters.

Preferably, said fine granulates and / or said coarse aggregates are at least partly composed of light aggregates.

More preferably, in the case of a mortar, all the fine aggregates consist of light aggregates. **. ' * ^ .û ·,

More preferably, in the case of a concrete, all the fine and / or coarse aggregates consist of light aggregates.

"Light aggregates" means mineral particles of natural or artificial origin, chosen from pumice stones, expanded clays, expanded shales, expanded slags, or expanded pellets, expanded glasses, expanded granules made from marble , granite, slate or ceramic, or a mixture of several of these.

The light aggregates used in the cementitious compositions according to the present invention advantageously have a dry density in the dry state of between 1000 kg / m 3 and 1600 kg / m 3.

Particularly fine and light aggregates are clays or expanded shales of actual density in the dry state of between 1000 kg / m3 and 1400 kg / m3. .

In particular, light coarse aggregates are chippings of clay or expanded shale having a dry density of between 1000 and 1400 kg / m3, in particular of a maximum diameter of less than 14 mm, and crush strength at least greater than 4 N / mm 2, preferably greater than 6 N / mm 2, more preferably greater than 8 N / mm 2.

The actual density of light particles in the dry state (standard NF EN 13055-1 of December 2002 (Light Aggregates) which refers for the method of calculation to standard EN 1097-6 of June 2001 (Tests to determine the mechanical characteristics and physical aggregates)) is preferably less than 1600 kg / m3 in order to obtain a lightweight structural and insulating concrete or mortar. There are light particles with a density of between 1600 and 2000 kg / m3, but they do not sufficiently lighten the concrete or the mortar obtained to develop them. insulating properties that are sought after. Particles with densities below 800 kg / m3 are too weak (easily crushed) to obtain a structural concrete with a minimum compressive strength of 25 MPa.

The particles whose density is greater than 2000 kg / m3 are particles used in conventional concrete, too heavy to be used mainly in light concrete.

Preferably, the light, fine and / or coarse aggregates are treated with a hydrophobic compound such as a pure resin or in the form of an emulsion, or such as an organic or inorganic gel, in order to reduce the water absorption and the hydrophobicity of said aggregates.

Advantageously, the total mass of the fine and / or coarse aggregates is at least greater than 550 kg per cubic meter of said cementitious composition, in particular at least greater than 60 kg / m3, preferably at least greater than 650 kg / m3, more preferably at least greater than 675 kg per m3.

The present invention also relates to the use of a cementitious composition as described above, for the implementation of an insulating slurry, which, in the dry state, is characterized by a thermal conductivity of less than 0.6 W / mK, in particular less than 0.55 W / mK, preferentially less than 0.5 W / mK, still more preferably less than 0.45 W / mK

The cementitious composition according to the present invention may advantageously be used for the implementation of a fluid insulating grout. "Fluid" slurry means a slurry with a Marsh cone flow value of less than 30 seconds (French standard P18-358).

More particularly, the cementitious composition according to the present invention can be used for the implementation of a viscous insulating slurry having a Marsh cone flow value between 30 and 60 seconds.

In another particular embodiment, the present invention also relates to the use of a cirhedral composition as described above, for the implementation of an insulating mortar, which, when cured, in the dry state, is characterized by a compressive strength of at least 20 MPa after 28 days, preferably at least 25 MPa after 28 days and more preferably at least 30 MPa after 28 days, and a thermal conductivity of less than 0.6 W / mK, especially less than 0.55 W / mK, preferably less than 0.5 W / mK, still more preferably less than 0.45 W / mK

The use of a mortar having insulating properties can be particularly advantageous, particularly in the context of the construction of a building based on constructive elements, for example concrete blocks, especially light ones that are hollow or solid.

The food composition according to the present invention can advantageously be used for the implementation of an insulating mortar, fluid. By mortar "fluid" is meant a mortar whose spreading mini-cone is greater than 300 mm. The production of fluid mortar can be particularly advantageous especially in the context of the production of insulating screeds for floors or for roof insulation. .

In another particular embodiment, the present invention relates to the use of a cementitious composition as described above, for the implementation of an insulating concrete, which, when cured, in the dry state, is characterized by a compressive strength of at least 20 MPa after 28 days, preferably at least 25 MPa after 28 days and more preferably 30 MPa after 28 days, and a thermal conductivity of less than 0.6 W / mK, especially lower at 0.55 W / m. K, preferably less than 0.5 W / m.K, more preferably less than 0.45 W / m.K.

Advantageously, the cementitious composition according to the present invention is used for the implementation of an insulating mortar or concrete, fluid, especially a mortar or self-placing concrete.

By "fluid" concrete is meant a concrete whose subsidence according to the norm N F EN 206-1 corresponds to the classes S4 or S5, ie a slump greater than 160 mm (S4) or 220 mm (S5).

"Self-compacting" means a concrete whose subsidence according to the NF EN 206-1 standard corresponds to class S5, ie a sag greater than 220 mm.

The present invention is illustrated by the following nonlimiting examples.

Examples 1 Materials used. 1.1 Cements ·

The cirrients used originated from Toulouse de Gaurain (France).

Two types of cements were tested: CEM I 52.5 N (> 95% Portland clinker, traces of calcium sulphate), Blaine specific surface area 4000 cm2 / g. CEM 11 / A-LL 42.5 R (88% Portland clinker, 12% limestone, traces of calcium sulphate), Blaine specific surface area 4100 cm 2 / g. 1.2 Pozzolanic Additions - silico-aluminous fly ash of the Silicoline type distributed by the company of the French manufacturer of the French market, from the Carling thermal power station (density 2.27% Blaine specific surface area 3420 cm2 / g, S02 content 56.5%). and AI203 of 24.8%). densified silica of the Gondensil S95 DM type distributed by Sika (France) (density 2.29, BET specific surface area 23 m 2 / g (according to product technical sheet), 95.7% SiO 2 content ). - ground slag produced by S.R.T. Grand-Couronne, France (density 2.91 Blaine specific surface area 4560 cm -1, CaO contents 40.9% and AI203 10.2%). metakaolin obtained by calcination of a kaolin clay, distributed by Argeco under the trade name Argicem. Density 2500 kg / m3, BET specific surface 16m2 / g, Si02 + Al203 content of 93%. 1.3 Adjuvants

The superplasticizer used, with the sole exception of sample 2 of Comparative Example 1, is Cimfluid Adagio 3019, marketed by Axim (Sika). It is a superplasticizer of the polycarboxylate type. The viscosing agent used is Collaxim SF, sold by the company Axim (Sika). It is a viscosity agent based on hydroxyethylcellulose, unmodified hydrophobic. The air entrainment agent used is Cimpore AE 21, sold by the company Axim (Sika). Cimpore AE 21 contains an alkene (C14-18) of sodium sulphonate (CAS RN: 68439-57-6) and a cocoalkyl of N, N-bis (2-ethanol) of alkylamide (CAS RN: 68603 -42-9). 2 Methods 2.1 Protocol for making cement matrix samples. The cement was mixed with the addition water in a baker-type mixer (Rayneri). The mixing protocol followed the following steps: • Introduction of cement, and additions; . • Water and admixtures are pre-weighed and reserved; • Mixing 30 seconds at low speed (25 rpm); • Introduction of all the water of addition Incorporating the viscosing agent (for any viscosing agent, the time of retention in the water before incorporation in the batch must not exceed 2 minutes) in 30 seconds without stop of the kneader; . . • Introduction of the superplasticizer without stopping the mixer; • Mixing for 1 minute at low speed; • Rest for 1 minute, during which the bottom and sides of the bowl are manually scraped to break any lumps and homogenize the mixture again; • 2 minute mixing at high speed (50 rpm); • Emptying the mixer.

All the specimens necessary for the characterization of the mechanical properties of the material in the cured state were made in 4 × 4 × 16 cm prismatic molds and then cured in accordance with the NF EN 196-1 standard (April 2006).

All the specimens necessary for the characterization of the dry density and the thermal conductivity of the material were made in cubic molds of 10 cm of edge and then subjected to a cure according to the standard NF EN 196-1 (April 2006) .

The placing in the molds can be carried out by gravity if the grout or mortar are very fluid or by means of a vibrating table for grouts or mortars of firm consistency. 2.2 Characterizations

The flexural and compressive strengths are measured according to standard NF EN 196-1 (April 2006).

The density in the fresh state is measured according to standard NF EN 1015-6 (October 1999).

The fresh air content is measured according to standard NF EN 1015-7 (October 1999). The mini-cone spread is measured according to the procedure described in chapter 5 of the "Results and recommendations" of the French national project CALIBE (July 2004).

The thermal conductivity in the cured state is measured on dry material by the hot wire method according to a suitable procedure (measurement at 20 ° C only) of the NF EN 993-15 standard (September 1998). ·

The drying is carried out in a regulated enclosure at 105 ° C. ± 5 ° C. until two successive weighings do not differ by more than 0.05% between them. 3 Results

All the quantities of materials indicated in carrying out the samples of the following examples were calculated to obtain a volume of 1 m 3 of fresh cementitious matrix. In practice these quantities have been reduced to a volume of 10 liters of dough, respecting the proportions of all the elements, in order to be manipulated in the laboratory.

By "binder" is meant the sum of cement and pozzolanic additions.

Comparative Example 1 (Prior art)

Two comparative samples were made with CEM I 52.5 N cement and according to formulas described in the prior art.

Sample 1. corresponding to the cement matrix of Example 2 of the patent application FR 11 61028.

The cement represents 69.5% (by weight) of the binder and the fly ash 30.5% (by weight) of the binder. 238 liters of effective water are used. The superplasticizer represents 0.35% (by weight) relative to the cement, and the viscosity agent represents 0.5% (by weight) relative to the cement.

Sample 2 corresponding to the cement matrix of Example 4 of Patent EP 2 203 400.

The cement represents 73% (by mass) of the binder and the fly ash 27% (by mass) of the binder. 133 liters of effective water are used. The superplasticizer, Glenium 27 marketed by BASF, represents 0.96% (by weight) relative to the cement. Glenium 27 is a non-chlorinated superplasticizer, modified polycarboxylic ether type. The plasticizer, Pozzol 391 N marketed by the company BASF, represents 0.32% (by weight) relative to the cement. Pozzplith 391 N is a non-chlorinated plasticizer of lignosulphonate type.

The values of the ratios Eeff / L, Add / L and the masses of the main constituents for these two samples according to the prior art are shown in Table 1 below.

Table 1

The technical characteristics of these two samples according to the prior art are presented in Table 2.

Table 2

Example 2 Cementary Matrix Containing Fly Ash, a Superplasticizer and a Viscosity Agent

Three samples, numbered 3, 4 and 5, were made with CEM I 52.5N, and a sample numbered 6 was made with CEM II / A-LL 42.5 R. Samples 4, 5 and 6 contained fly ash, water, a superpixifier and a viscous agent. Sample 3 contains no addition, it constitutes a reference sample outside the scope of the present invention.

The proportions of cement and addition, as a percentage by weight of the binder, and the masses of the main constituents vary according to Table 3. The ratios Eeff / L and Add / L, for each sample, are also indicated in Table 3 4.

Table 3

For each of the four samples, the superplasticizer represents 0.35% (by weight) relative to the cement and the viscosity agent represents 0.5% (by weight) relative to the cement.

The technical characteristics of these samples are presented in Table 4.

Table 4

Example 3 Cementary matrix containing fly ash, a superplasticizer, without viscosity agent

Three samples, numbered 7, 8 and 9 were made with CEM I 52.5N. Sample numbered 10 was made with CEM II / A-LL 42.5 R. Samples 8, 9 and 10 contain fly ash, water, superplasticizer. Sample 7 does not contain addition, it constitutes a reference sample outside the scope of the present invention. '""

None of Samples 7, 8, 9 and 10 contain viscosifier.

For each of the four samples, the superplasticizer represents 0.35% (by weight) relative to the cement.

The proportions of cement and addition, as a percentage by weight of the binder, and the masses of the main constituents vary according to Table 5. The ratios Eeff / L and Add / L, for each sample, are also indicated in Table 5.

Table 5.

The technical characteristics of these samples are presented in Table 6.

Table 6

Example 4 Cementitious Matrix Containing an Air Trainer

Four samples, numbered 11 to 14, were made with CEM I 52.5N. Sample 15 was made with CEM II / A-LL 42.5R. All samples contain fly ash, water, superplasticizer and an air entraining agent (Cimpore AE 21).

For each of the five samples, the superplasticizer represents 0.35% (by weight) relative to the cement and the air entraining agent represents 0.2% (by weight) relative to the cement. '

The proportions of cement and addition, as a weight percentage of the binder, the ratios Eeff / L and Add / L, and the masses of the main constituents vary according to Table 7.

- laoieau i

The technical characteristics of these samples are presented in Table 8.

Table 8

There is little difference from the results obtained in Examples 2 and 3. The addition of an air entrainer does not significantly change the technical characteristics.

Example 5 Cementitious Matrix Containing a Blast Furnace Slag

Two samples, numbered 16 and 17, were made with CEM I 52.5N. Two samples, numbered 18 and 19 were made with CEM II / A-LL 42.5 R. All samples contain blast furnace slag, water, and superplasticizer.

For the four samples, the superplasticizer represents 0.35% (by weight) relative to the cement.

Samples 16 and 17 contain a viscosity agent. The viscosity agent is 0.5% (by weight) relative to the cement.

Samples 18 and 19 do not contain a viscosity agent.

The proportions of cement and addition, as a weight percentage of the binder, the ratios Eeff / L and Add / L and the masses of the main constituents vary according to Table 9.

Table 9

The technical characteristics of these samples are presented in Table 10.

Table 10

Example 6 Cementary matrix containing a mixture of two pozzolanic additions

Three samples, numbered 20, 21 and 22, were made with CEM I 52.5N. All samples contain fly ash, water, viscosity agent and superplasticizer.

For the three samples, the superplasticizer represents 0.35% (by weight) relative to the cement, and the viscosity agent represents 0.5% (by weight) relative to the cement.

Samples 20 and 21 contain silica fume in addition to fly ash. Sample 22 contains blast furnace slag in addition to fly ash.

The proportions of cement and the various additions, as a percentage by weight of the binder, the ratios Eeff / L and Add / L and the masses of the main constituents vary according to Table 11.

Table 11

The technical characteristics of these samples are presented in Table 12.

Table 12

Example 7 Cementitious Matrix Containing a Metakaolin

Two samples, numbered 23 and 24, were made with CEM I 52.5 N. Both samples contained a metakaolin, water, a viscosity agent and a superplasticizer.

For both samples, the superplasticizer represents 0.35% (by weight) relative to the cement, and the viscosity agent represents 0.5% (by weight) relative to the cement.

The proportions of cement and the various additions, in mass percentage of the binder, the ratios Eeff / L and Add / L and the masses of the main constituents vary according to Table 13.

Table 13

The technical characteristics of these samples are presented in Table 14.

Table 14

Claims (15)

1. Cementary matrix comprising, in the fresh state, a Blaine fineness cement of less than 6000 cm 2 / g, at least one pozzolanic addition, of the effective water, characterized in that it has: an Eeff / L ratio inclusive between about 0.4 and 0.7, especially between 0.45 and 0.65, preferably between 0.5 and 0.6 and an Add / L ratio of between 0.40 and 0.70, especially between 0.50 and 0.70, preferably between 0.55 and 0.65, the ratio Add / L being between 0.60 and 0.70 when the pozzolanic addition comprises a blast furnace slag, where Eeff represents the volume in liters of effective water implemented in the cement matrix, Add represents the weight, in kg, of pozzolanic addition contained in said matrix, and L represents the total mass, in kg, of cement and pozzolanic addition contained in said matrix. 2. cementitious matrix according to claim 1 characterized in that it comprises a pozzolanic addition selected from fly ash, silica fumes, blast furnace slag, zeolites, metakaolin, and a combination of several of these additions, including combinations of fly ash and silica fume, fly ash and zeolites, blast furnace slag and fly ash, metakaolin and blast furnace slag, metakaolin and fly ash, metakaolin and fumes of silica, metakaolin and zeolites, blast furnace slag and silica fumes. 3. cementitious matrix according to any one of the preceding claims characterized in that it comprises at least one viscosing agent, selected from cellulose ethers, including polysaccharides, hydroxyalkylcelluloses, hydroxyethylcelluloses, methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, ethylhydroxyethylcellulose, poly (ethylene oxide), polyvinyl alcohols, polyamides, or a mixture thereof. 4. cementitious matrix according to any one of the preceding claims characterized in that it has a dry density in the dry state of less than 1500 kg / m3, especially less than 1450 kg / m3, preferably less than 1400 kg / m3 . 5. Cementitious composition characterized in that it contains a cementitious matrix according to any one of the preceding claims, and fillers whose particle size is less than 0.15 mm. 6. Cementitious composition characterized in that it contains a cement matrix according to any one of claims 1 to 4, fine aggregates whose particle size is between 0.15 mm and 4 mm, possibly fillers, and not does not contain coarse aggregates, preferably the mass of fine aggregates being at least greater than 250 kg per cubic meter of said composition, in particular at least greater than 300 kg per cubic meter, preferably at least greater than 350 kg per cubic meter, more preferably at least greater than 375 kg per m3. 7. Cementitious composition characterized in that it contains a cementitious matrix according to any one of claims 1 to 4, fine aggregates whose particle size is between 0.15 mm and 4 mm, and coarse aggregates whose particle size is greater than 4 mm, and possibly fillers, preferably the total mass of the fine and coarse aggregates being at least greater than 550 kg per m 3 of said composition, in particular at least greater than 600 kg per m 3, preferably at least greater than 650 kg per m3, still more preferably at least greater than 675 kg per m3. 8. Cementitious composition according to any one of the preceding claims, characterized in that the effective volume of water is at least 180 liters per m3 of cementitious composition, especially at least 200 liters, preferably at least 220 liters. still more preferably at least 240 liters. 9. Cementitious composition according to any one of claims 7 or 8, characterized in that said fine aggregates and / or said coarse aggregates are at least partly composed of light aggregates. 10. Composition according to claim 9 characterized in that the lightweight aggregates are selected from pumice stones, expanded clays, expanded shales, expanded or expanded slags bouletés, expanded glasses, expanded granules based marble, granite, slate or ceramic, or a mixture of several of these. 11. Composition according to any one of claims 9 or 10 characterized in that the fine aggregates, fine and / or coarse, are treated with a hydrophobic compound, such as a pure resin or in the form of an emulsion, or such as an organic or inorganic gel; to reduce the water absorption and hydrophobicity of said aggregates. 12. Use of the cementitious composition according to claim 5 for the implementation of an insulating slurry, which, in the dry state, is characterized by a thermal conductivity of less than 0.6 W / mK, especially less than 0, 55 W / mK, preferentially less than 0.5 W / mK, still preferably less than 0.45 W / mK 13. Use of the cementitious composition according to any one of claims 6 or 8 to 11 for the implementation of an insulating mortar, which, cured, in the dry state, is characterized by a compressive strength of at least 20 MPa after 28 days, preferably at least 25 MPa after 28 days and more preferably at least 30 MPa after 28 days, and a thermal conductivity of less than 0.6 W / mK, especially less than 0, 55 W / mK, preferentially less than 0.5 W / mK, still preferably less than 0.45 W / mK 14. Use of the cementitious composition according to any one of claims 7 to 11 for the implementation of an insulating concrete, which, cured, in the dry state, is characterized by a compressive strength of at least 20 MPa after 28 days, preferably at least 25 MPa after 28 days and more preferably at least 30 MPa after 28 days, and a thermal conductivity of less than 0.6 W / mK, especially less than 0.55 W / mK, preferably less than 0.5 W / mK, still more preferably less than 0.45 W / mK 15. Use according to claims 13 or 14 for the implementation of a mortar or concrete insulation, fluid, including a mortar or self-placing concrete.