Construction material without a hydraulic binder

Patent metadata

Field	Value
Publication number	US-11905211-B2
Application number	US-201917275325-A
Country	US
Kind code	B2
Filing date	Sep 11, 2019
Priority date	Sep 12, 2018
Publication date	Feb 20, 2024
Grant date	Feb 20, 2024

Abstract

The invention relates to a method for producing a solid construction material which is preferably substantially free of hydraulic binder, comprising the steps of: a. extracting a mineral fraction comprising argillaceous particles of a soil; b. optionally adjusting the particle size of the mineral fraction extracted, in particular in relation to its clay, sand, gravel or loam content, if necessary; c. preparing a first aqueous grout from at least one part of the mineral fraction extracted and optionally adjusted in terms of particle size; d. adding a dispersant that can disperse the argillaceous particles in the first grout in order to obtain a second aqueous grout, e. adding a coagulant that can promote the agglomeration of the argillaceous particles in the second grout in order to obtain an aqueous construction material grout; f introducing the construction material grout into a formwork; and g. allowing the evaporation of the water contained in the material grout in order to obtain a solid construction material.

First claim

The invention claimed is:

1. A method for producing a solid construction material, the method comprising:
extracting a mineral fraction comprising argillaceous particles from a soil;
preparing a first aqueous grout from at least one part of the extracted mineral fraction;
adding a dispersing agent to the first aqueous grout to disperse the argillaceous particles there to obtain a second aqueous grout,
adding a coagulating agent to the second aqueous grout to agglomerate the argillaceous particles therein to obtain an aqueous construction material grout;
introducing the aqueous construction material grout into a formwork; and
allowing the evaporation of the water contained in the aqueous construction material grout to obtain the solid construction material,
wherein the solid construction material is a supporting element having a compressive strength of at least 1.4 MPa.

2. The method according to claim 1 , wherein the supporting element is a wall, brick, slab or pillar.

3. The method according to claim 1 , wherein the dispersing agent is selected from phosphates and polyacrylate salts.

4. The method according to claim 1 , wherein the coagulating agent is an inorganic salt having a divalent metal cation of carbonate, chloride, nitrate, sulfate, oxide, or hydroxide.

5. The method according to claim 1 , wherein the building material comprises at least 5% by weight of argillaceous particles, relative to the total dry weight of mineral material contained in the mineral fraction.

6. The method according to claim 1 , wherein the building material comprises 0.4 to 2 wt % dispersing agent, based on the total dry weight of clays.

7. The method according to claim 1 , wherein the construction material comprises at least 1% by weight of coagulating agent relative to the total dry weight of clays.

8. The method according to claim 1 , wherein the aqueous construction material grout, at the time of introduction into the mold, contains 5 to 30% water.

9. The method according to claim 1 , wherein the dispersing agent is a phosphate, the coagulating agent is an alkaline earth metal salt, and the molar ratio [Me 2+ /PO 4 3− ] the metal cation of the alkaline earth metal salt and the phosphate in the aqueous construction material grout is greater than 1.

10. The method according to claim 1 , wherein the solid construction material is substantially free of a hydraulic binder.

11. The method according to claim 1 , further comprising adjusting the granulometry of the extracted mineral fraction.

12. The method according to claim 11 , wherein adjusting the granulometry comprises altering the clay, sand, gravel, or loam content of the extracted mineral fraction.

13. The method according to claim 3 , wherein the polyacrylate salts are monovalent salts.

14. The method according to claim 1 , wherein the coagulating agent is an alkaline earth metal salt of carbonate, chloride, nitrate, sulfate, oxide, or hydroxide.

15. The method according to claim 1 , wherein the building material comprises 5 to 30% by weight of argillaceous particles relative to the total dry weight of mineral material contained in the mineral fraction.

16. The method according to claim 1 , wherein the construction material comprises 1% to 2% by weight relative to the total dry weight of clays.

17. The method according to claim 9 , wherein the molar ratio [Me 2+ /PO 4 3− ] of the metal cation of the alkaline earth metal salt and the phosphate in the aqueous construction material grout is between 2 and 5.

Assignees

• Eth Zuerich
• Eth Zuerich

Inventors

• Landrou Gnanli
• Brumaud Coralie
• Habert Guillaume

Classifications

• C04B14/361 Primary

  Soil, e.g. laterite · CPC title

• C04B14/10

  Clay {(sepiolite C04B14/042; grog C04B18/025)} · CPC title

• C04B24/2641

  Polyacrylates; Polymethacrylates · CPC title

• C04B2103/0067

  the ingredients being formed in situ by chemical reactions or conversion of one or more of the compounds of the composition · CPC title

• C04B2103/408

  Dispersants · CPC title