Dense mortar based on binary ettringite binder, comprising at least one poly(alkylene oxide) comb polymer and at least one structuring organic resin

1. A dense mortar which comprises: (i) an ettringite binder comprising both calcium sulphate and a calcium aluminate mineral compound, the calcium aluminate mineral compound comprising oxides of calcium C and of aluminium A, which are soluble and combined in one or several crystallized and/or amorphous mineralogical phases in such proportions that:

the useful C/A molar ratio of the calcium aluminates mineral compound is in the range of 1.2 to 2.7;

the sum in weight of the useful C+A phases represents at least 30% of the total weight of the mineral compound,

(ii) at least one poly(alkylene oxide) comb polymer and,

(iii) at least one organic resin, wherein the mortar contains less than 2% by weight of said organic resin.

2. The dense mortar according to claim 1 , wherein the mortar comprises at least 0.3% by weight of organic resin, based on the weight of the mortar.

3. The dense mortar according to claim 1 , characterised in that wherein the mortar comprises 0.05% to 0.3% of poly(alkylene oxide) comb polymer based on the weight of the mortar.

4. The dense mortar according to claim 1 , wherein said organic resin account for 1% by weight of the mortar, or less.

5. The dense mortar according to claim 1 , wherein the poly(alkylene oxide) comb polymer is selected from the group consisting of the copolymers of carboxylic acids and carboxylic esters of poly(alkylene glycol), copolymers of carboxylic acids and poly(alkylene glycol) amide, copolymers of carboxylic acids and poly(alkylene glycol) imide, copolymers of carboxylic acids and vinylic ethers of poly(alkylene glycol), and mixtures of thereof.

6. The dense mortar according to claim 1 wherein the organic resin comprises at least one polymer selected from the group consisting of poly(vinyl acetate), powdered copolymers of vinyl and ethylene acetate, copolymers formed by copolymerisation of 2 or more monomers selected from the group consisting of ethylene, vinyl acetate, vinyl esters of versatic acids, vinyl chloride, vinyl laurate, styrene, butadiene, alkyl acrylate, alkyl methacrylate, maleic anhydride and its derivatives.

7. The dense mortar according to claim 6 wherein the mortar comprises 0.2% by weight of the mortar of at least one poly(alkylene oxide) comb polymer, and 1% by weight of the mortar of at least one powdered copolymer of vinyl and ethylene acetate.

8. The A dense mortar according to claim 1 , wherein the organic resin comprises at least one polyvinyl alcohol.

9. The dense mortar according to claim 8 wherein the mortar comprises 0.2% by weight of the mortar of at least one poly(alkylene oxide) comb polymer, and 1% by weight of the mortar of at least one polyvinyl alcohol.

10. The dense mortar according to claim 1 wherein the weight ratio of calcium aluminate mineral compound/calcium sulphate within the ettringite binder is between 0.5 and 47.

11. The dense mortar according to claim 1 wherein the molar ratio of calcium sulphate/aluminium oxide A in the ettringite binder is between 0.5 and 2.

12. The dense mortar according to claim 1 wherein the useful C/A molar ratio of the calcium aluminate mineral compound within the ettringite binder is between 1.3 and 2.5.

13. The dense mortar according to claim 1 wherein the molar ratio of calcium sulphate/aluminium oxide A in the ettringite binder is between 0.6 and 1.8.

14. The dense mortar according to claim 1 wherein the mortar exhibits at the time of mixing with water a water/solids weight ratio lower than 0.5.

15. The dense mortar according to claim 1 , wherein the mortar does not comprise any Portland cement or hydraulic lime.

16. The dense mortar according to claim 1 , wherein the sum in weight of useful C+A phases accounts for at least 50% by weight of the total weight of the calcium aluminates mineral compound.

17. The dense mortar according to claim 1 , wherein the calcium aluminate mineral compound is obtained through baking in a furnace at a temperature of over 1100° C., in the form of one or several melted or sintered clinkers that contain crystallised phases or amorphous phases.

18. The dense mortar according to claim 1 , wherein the calcium aluminate mineral compound is under the form of a crystallised mineralogical phase selected from the group consisting of CA, C12A7, C3A, C4A3$, or under the form of an amorphous phase, or under the form of a mixture of at least one of said crystallised mineralogical phases and an amorphous phase.

19. The dense mortar according to the claim 18 wherein the calcium aluminate mineral compound contains at least 30% by weight of C12A7 based on the total weight of the mineral compound.

20. The dense mortar according to claim 1 wherein the calcium aluminate mineral compound contains at least one crystallised mineralogical phase selected from the group consisting of C2A(1−x)Fx, C2S, C2AS, C3S, and mixtures thereof, where x is an integer from 0 to 1.

21. The dense mortar according to claim 1 wherein the calcium aluminate mineral compound is ground and exhibits a Blaine surface area greater than or equal to 1500 cm 2 /g.

22. The dense mortar according to the claim 21 wherein the calcium aluminate mineral compound is ground to a Blaine surface area comprised between 2000 cm 2 /g and 5000 cm 2 /g.

23. The dense mortar according to claim 1 , wherein the calcium sulphate is derived from a compound selected from the group consisting of anhydrites, hemihydrates, gypsum and mixtures thereof.

24. The dense mortar according to claim 1 , further comprising:

chalk fillers or siliceous sands: from 25 to 85% by weight based on the total weight of the dry mortar,

lime and/or Portland cement: from 0% to 3.5% by weight based on the total weight of the dry mortar, and

rheological additives and/or setting regulating additives.

25. The dense mortar according to claim 24 , wherein the mortar comprises:

chalk fillers or siliceous sands: from 50 to 80% by weight based on the total weight of the dry mortar,

lime and/or Portland cement: from 0% to 0.5% by weight based on the total weight of the dry mortar, and

complementary rheological additives and/or setting regulating additives.

26. The dense mortar according to claim 24 wherein the rheological additives account for from 0.1% to 0.5% of the total weight of the dry mortar, and the setting regulating additives account for 0.1% to 0.5% of the total weight of the dry mortar.

27. The dense mortar according to any claim 1 wherein the mortar is obtained by mixing with water in a quantity such that the water/solid weight ratio is less than 0.5.

28. The dense mortar according to claim 8 wherein the polyvinyl alcohol is altered by the inclusion of carboxylic acid groups in its structure.

29. The dense mortar according to claim 1 , further comprising Portland cement and/or hydraulic lime at a content of less than 3.5% by weight based on the total weight of dry mortar.