Hydraulic cement and composition employing the same

• US 4,997,484 A
• Filed: 06/05/1990
• Issued: 03/05/1991
• Est. Priority Date: 12/11/1987
• Status: Expired due to Term

• Current Assignee: Lone Star Industries, Inc. (Pennsylvania) (Buzzi Unicem SPA)
• Original Assignee: Lone Star Industries, Inc. (Pennsylvania) (Buzzi Unicem SPA)
• Inventors: Gravitt, Billy B., Heitzmann, Richard F., Sawyer, James L.
• Primary Examiner(s): GROUP, KARL E
• Application Number:
  US07/533,361
• Time in Patent Office: 273 Days
• Field of Search: 106/705, 106/708, 106/DIG. 1, 106/85, 106/315
• US Class Current: 106/708
• CPC Class Codes: C04B 22/0013 Boron compounds
• CPC Class Codes: C04B 22/062 of the alkali or alkaline-earth metals
• CPC Class Codes: C04B 22/10 containing carbon in the anion
• CPC Class Codes: C04B 24/06 containing hydroxy groups
• CPC Class Codes: C04B 24/18 Lignin sulfonic acid or derivatives thereof, e.g. sulfite lye
• CPC Class Codes: C04B 24/226 Sulfonated naphtalene-formaldehyde condensation products
• CPC Class Codes: C04B 24/2641 Polyacrylates; Polymethacrylates
• CPC Class Codes: C04B 28/021 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 Class Codes: C04B 40/0039 Premixtures of ingredients
• CPC Class Codes: C04B 40/065 Two or more component mortars
• CPC Class Codes: C04B 7/243 Mixtures thereof with activators or composition-correcting additives, e.g. mixtures of fly ash and alkali activators
• CPC Class Codes: Y02P 40/10 Production of cement, e.g. improving or optimising the production methods; Cement grinding
• CPC Class Codes: Y10S 106/01 Fly ash

Abstract

A hydraulic cement is formed from a Class C fly ash, an alkali metal activator, and citric acid. Mortar and concrete compositions can be prepared with this hydraulic cement. The cement is particularly useful in producing mortar and concrete compositions that achieve high strengths in a short time, in particular, a mortar having a strength of at least 2500 psi in 24 hours, when cured at room temperature.

Claims

1. A hydraulic cement consisting essentially of, by weight the following cement forming constituents:

from about 90.8 to 99 parts Class C fly ash

from about 0.4 to 4.2 parts alkali metal activator

from about 0.6 to 5 parts citric acid

from about 0 to 3 parts set control materials, said alkali metal activator being selected from the class consisting of potassium hydroxide, potassium carbonate, sodium hydroxide, and sodium carbonate; and

said admixture is at least one material selected from the class consisting of borax;

a sodium salt of a copolymer of an unsaturated carboxylic acid and the hydroxyalkyl ester of such acid;

a modified lignosulfonate, with catalyst; and

a dispersion of sulfonated naphthalene formaldehyde condensate, a gluconate, and a lignosulfonate.

2. The hydraulic cement of claim 1 wherein the alkali metal activator is potassium hydroxide.

3. The hydraulic cement of claim 1 mixed with from 0.165 to 0.220 part water for each part of cement forming constituents.

4. The hydraulic cement of claim 3 wherein the amount of water is from 0.18 to 0.22 part.

5. A mortar formed from the hydraulic cement of claim 1 including sand in a ratio to cement forming constituents of 1.5-3.0:

1.0.

6. The mortar of claim 5 wherein the ratio is 1.5-2.5:

1.0.

7. The hydraulic cement of claim 1 having from 0.6 to 3.0 parts citric acid and from 1.0 to 2.9 parts potassium hydroxide.

8. The hydraulic cement of claim 1 having from 3.0 to 5.0 parts citric acid and from 0.4 to 3.8 parts potassium hydroxide.

9. A two part composition for hydraulic cement, wherein the two parts are blended prior to preparation of the cement, consisting essentially of by weight:

a. a first part of from about 90.8 to 99 parts, Class C fly ash; and

b. a second part containing;

(1) from about 0.4 to 4.2 parts alkali metal activator

(2) about 0.6 to 5 parts citric acid; and

(3) about 0 to 3 parts admixture,

wherein said alkali metal activator is selected from the class group consisting of potassium hydroxide, potassium carbonate, sodium hydroxide, and sodium carbonate; and

said admixture is at least one material selected from the class consisting of borax;

a sodium salt of a copolymer of an unsaturated carboxylic acid and the hydroxyalkyl ester of such acid;

a modified lignosulfonate, with catalyst; and

a dispersion of sulfonated naphthalene formaldehyde condensate, a gluconate, and a lignosulfonate.

10. The composition of claim 9 wherein the alkali metal activator is potassium hydroxide.

11. The composition of claim 9 mixed with from 0.165 to 0.220 part water for each part the hydraulic cement composition.

12. The composition of claim 11 wherein the amount of water is from 0.18 to 0.22 part.

13. A mortar formed from the composition of claim 9 including sand in a ratio to hydraulic composition of 1.5-3.0:

1.0.

14. The mortar of claim 13 wherein the ratio is 1.5-2.5:

1.0.

15. The composition of claim 9 having from 0.6 to 3.0 parts citric acid and from 1.0 to 2.9parts potassium hydroxide.

16. The composition of claim 9 having from 3.0 to 5.0 parts citric acid and from 0.4 to 3.8parts potassium hydroxide.

17. The composition of claim 9 wherein the alkali metal activator is potassium hydroxide.

18. A hydraulic cement comprising, by weight, approximately:

96.29 parts Class C fly ash

1.41 parts potassium hydroxide

1.28 parts citric acid

1.02 parts borax

19. A hydraulic cement comprising, by weight, approximately:

95.98 parts Class C fly ash

1.40 parts potassium hydroxide

1.28 parts citric acid

1.02 parts borax

0.05 part sodium salt of a copolymer of an unsaturated carboxylic acid and the hydroxyalkyl ester of said acid

20. A hydraulic cement comprising, by weight, approximately:

96.41 parts Class C fly ash

1.28 parts potassium hydroxide

1.28 parts citric acid

1.03 parts borax

21. A hydraulic cement comprising, by weight, approximately:

96.53 parts Class C fly ash

1.16 parts potassium hydroxide

1.28 parts citric acid

1.03 parts borax

22. A hydraulic cement comprising, by weight, approximately:

96.66 parts Class C fly ash

1.03 parts potassium hydroxide

1.28 parts citric acid

1.03 parts borax

23. A hydraulic cement comprising, by weight, approximately:

96.79 parts Class C fly ash

0.90 part potassium hydroxide

1.28 parts citric acid

24. 03 parts borax

25. A hydraulic cement comprising, by weight, approximately:

94.95 parts Class C fly ash

3.79 parts potassium carbonate

1.26 parts citric acid