Fly ash-containing construction material with improved strength and water resistance and methods of forming the same

Patent metadata

Field	Value
Publication number	US-11040912-B2
Application number	US-201615770047-A
Country	US
Kind code	B2
Filing date	Oct 14, 2016
Priority date	Oct 20, 2015
Publication date	Jun 22, 2021
Grant date	Jun 22, 2021

Abstract

The invention is directed to a fly ash containing construction material having improved strength and water resistance. The fly ash containing material includes fly ash, an alkali solution comprising sodium hydroxide, and water. The invention further provides a geopolymerization method of forming a fly ash containing material.

First claim

What is claimed:

1. A mixture for the fabrication of a construction material, the mixture consisting essentially of:
fly ash;
an alkali solution comprising sodium hydroxide; and
water,
wherein the ratio of fly ash to water to sodium hydroxide ranges from 12:2.5:1 to 17:2.5:1, based upon weight percentage.

2. The mixture of claim 1 , wherein the fly ash is a mixture of Class C fly ash and Class F fly ash.

3. The mixture of claim 2 , wherein the mixture is made of at least 50% by weight of Class C fly ash.

4. The mixture of claim 1 , wherein the fly ash consists of Class C fly ash.

5. The mixture of claim 1 , wherein the fly ash consists of Class F fly ash.

6. The mixture of claim 1 , wherein the ratio of fly ash to water to sodium hydroxide is 14:2.5:1.

7. The mixture of claim 1 , wherein the construction material is devoid of aggregates or sodium silicate.

8. The mixture of claim 1 , wherein the construction material has a compressive strength of about 75 to about 100 MPa.

9. The mixture of claim 1 , wherein the construction material has a flexural strength of at least about 4 MPa and at most about 10 MPa.

10. The mixture of claim 1 , wherein the alkali solution consists of sodium hydroxide and water.

11. The mixture of claim 1 , wherein the alkali solution further comprises calcium hydroxide.

12. A mixture for the fabrication of a construction material, the mixture consisting essentially of:
fly ash;
an alkali solution comprising sodium hydroxide; and
water,
wherein the ratio of fly ash to water to sodium hydroxide ranges from 10.5:2.5:1 to 6:2.5:1, based upon weight percentage.

Assignees

• Univ Arizona

Inventors

• Zhang Jinhong
• Feng Qingming

Classifications

• Y02P40/10

  Production of cement, e.g. improving or optimising the production methods; Cement grinding · CPC title

• C04B28/008

  Mineral polymers other than those of the Davidovits type, e.g. from a reaction mixture containing waterglass · CPC title

• C04B2111/10

  Compositions or ingredients thereof characterised by the absence or the very low content of a specific material · CPC title

• C04B2111/27

  Water resistance, i.e. waterproof or water-repellent materials · CPC title

• C04B28/021 Primary

  Ash cements, e.g. fly ash cements (fly ash as filler C04B18/08); Cements based on incineration residues, e.g. alkali-activated slags from waste incineration (alkali-activated combustion residues as such C04B7/243; mixtures of the lime-pozzuolane type C04B28/18); Kiln dust cements · CPC title