Addition of carbon dioxide to concrete mixtures

Patent metadata

Field	Value
Publication number	US-10392305-B2
Application number	US-201615076765-A
Country	US
Kind code	B2
Filing date	Mar 22, 2016
Priority date	Mar 24, 2015
Publication date	Aug 27, 2019
Grant date	Aug 27, 2019

Abstract

A method for reducing the net amount of carbon dioxide generated in the manufacture of concrete by pre-carbonating calcium rich cementitious materials prior to the addition of ordinary Portland cement is disclosed. Additionally, a composition of concrete is disclosed, which is manufactured by using a mixture of pre-carbonated cementitious materials and ordinary Portland cement.

First claim

What is claimed is:

1. A method for manufacturing concrete comprising:
(a) contacting a first slurry comprising a calcium-rich cementitious material in water with a carbon dioxide-rich gas to form a second slurry; and
(b) adding ordinary Portland cement to the second slurry without reducing the amount of water present in the second slurry from step (a),
wherein the concrete comprises calcite nanoparticles produced in situ and exhibits an increase in compressive strength of at least 10% compared to an identical concrete formed without the carbon dioxide-rich gas.

2. The method of claim 1 , further comprising adding aggregates and admixtures of cementitious materials to the second slurry.

3. The method of claim 1 , further comprising blending the second slurry.

4. The method of claim 1 , wherein the calcium-rich cementitious material is chosen from slaked lime, fly ash, metakaolin, cement kiln dust, blended ordinary Portland cement-based cements, ground granulated blast-furnace slag, limestone fines, and any combination thereof.

5. The method of claim 1 , wherein the carbon dioxide-rich gas is added by bubbling the carbon dioxide-rich gas into the first slurry.

6. The method of claim 1 , wherein the carbon dioxide-rich gas is from a post-combustion flue gas.

7. The method of claim 1 , wherein the carbon dioxide-rich gas is a byproduct of the manufacture of cement.

8. A method for manufacturing concrete comprising:
(a) contacting a neat calcium-rich cementitious material with a carbon dioxide-rich gas to form a carbonated powder;
(b) adding water to the carbonated powder to form a slurry; and
(c) adding ordinary Portland cement to the slurry, without reducing the amount of water present in the slurry from step (b),
wherein the concrete comprises calcite nanoparticles produced in situ and exhibits an increase in compressive strength of at least 10% compared to an identical concrete formed without the carbon dioxide-rich gas.

9. The method of claim 8 , further comprising adding aggregates and admixtures of cementitious materials to the slurry.

10. The method of claim 8 , further comprising blending the slurry.

11. The method of claim 8 , wherein the calcium-rich cementitious material is chosen from slaked lime, fly ash, metakaolin, cement kiln dust, blended ordinary Portland cement-based cements, ground granulated blast-furnace slag, limestone fines, and any combination thereof.

12. The method of claim 8 , wherein the carbon dioxide-rich gas is added by bubbling the carbon dioxide-rich gas into the slurry.

13. The method of claim 8 , wherein the carbon dioxide-rich gas is from a post-combustion flue gas.

14. The method of claim 8 , wherein the carbon dioxide-rich gas is a byproduct of the manufacture of cement.

15. The method of claim 1 , wherein the calcium-rich cementitious material is present in an amount of from 1% to 20% by weight, based on the weight of ordinary Portland cement.

16. The method of claim 1 , wherein the calcium-rich cementitious material is slaked lime present in an amount of 1% by weight, based on the weight of ordinary Portland cement.

Assignees

• Univ Alabama

Inventors

• Wang Jialai
• Qian Xin

Classifications

• C04B28/04 Primary

  Portland cements · CPC title

• C04B18/08

  Flue dust {, i.e. fly ash} · CPC title

• C04B18/162

  Cement kiln dust; Lime kiln dust · CPC title

• C04B22/10 Primary

  containing carbon in the anion, e.g. carbonates · CPC title

• Y02W30/95

  Cross-Sectional Technologies · mapped topic