Antifreeze composition for producing a durable concrete in cold temperature conditions

Patent metadata

Field	Value
Publication number	US-9376342-B2
Application number	US-201314425908-A
Country	US
Kind code	B2
Filing date	Sep 23, 2013
Priority date	Sep 25, 2012
Publication date	Jun 28, 2016
Grant date	Jun 28, 2016

Abstract

The present invention relates to an admixture for a cementitious composition and a method using said admixture for manufacturing a durable cementitious composition, in particular a concrete, in cold weather conditions, such as in winter time or in cold geographical areas.

First claim

The invention claimed is:

1. Admixture for a cementitious composition, comprising:
a) calcium nitrate,
b) aluminium nitrate,
c) a superplasticizer (SP), and
d) optionally, an air entraining agent (AEA),
wherein the admixture comprises:
62 to 82 weight %, relative to the total weight of the admixture, of calcium nitrate,
10 to 36 weight %, relative to the total weight of the admixture, of aluminium nitrate,
5 to 15 weight %, relative to the total weight of the admixture, of a superplasticizer (SP), and
0 to 1 weight %, relative to the total weight of the admixture, of an air entraining agent (AEA).

2. The admixture for a cementitious composition according to claim 1 , comprising:
a) calcium nitrate,
b) aluminium nitrate,
c) a superplasticizer (SP), and
d) an air entraining agent (AEA).

3. The admixture for a cementitious composition according to claim 1 , comprising:
a) 62 to 82 weight %, relative to the total weight of the admixture, of calcium nitrate,
b) 10 to 36 weight %, relative to the total weight of the admixture, of aluminium nitrate,
c) 5 to 15 weight %, relative to the total weight of the admixture, of a superplasticizer (SP), and
d) 0 to 1 weight %, relative to the total weight of the admixture, of an air entraining agent (AEA),

wherein the sum of components a), b), c) and d) adds up to 100 weight %.

4. Method for casting a cementitious solid comprising the steps of:
I) preparing a cementitious composition comprising mixing water, cement, the concrete admixture according to claim 1 , and optionally an aggregate;
II) casting the cementitious composition into a form; and
III) having the cementitious composition hardened into a cementitious solid.

5. Method according to claim 4 , wherein step I) comprises the steps of:
a) preparing a first composition comprising mixing water, calcium nitrate, a superplasticizer and, optionally, an air entraining agent;
b) preparing a second composition comprising cement, the first composition and optionally an aggregate;
c) preparing the cementitious composition by mixing aluminium nitrate with the second composition, before casting the cementitious solid.

6. The method of claim 4 , wherein at least the casting step takes place at a temperature below 0° C.

7. Method according to claim 4 , wherein the cementitious composition prepared in step I) comprises:
a) 2.5 to 3.5 weight %, relative to the weight of the cement, of calcium nitrate,
b) 0.5 to 1.0 weight %, relative to the weight of the cement, of aluminium nitrate,
c) 0.25 to 0.5 weight %, relative to the weight of the cement, of a superplasticizer (SP), and
d) 0 to 0.04 weight %, relative to the weight of the cement, of an air entraining agent (AEA).

8. The method of claim 4 , wherein at least the casting step takes place in cold weather conditions.

9. Cementitious composition comprising:
i) cement,
ii) water,
iii) an admixture for the cementitious composition comprising:
a) 2.5 to 3.5 weight %, relative to the weight of the cement, of calcium nitrate,
b) 0.5 to 1.0 weight %, relative to the weight of the cement, of aluminium nitrate,
c) 0.25 to 0.5 weight %, relative to the weight of the cement, of a superplasticizer (SP), and
d) 0 to 0.04 weight %, relative to the weight of the cement, of an air entraining agent (AEA), and

iv) optionally an aggregate.

10. The cementitious composition according to claim 9 , selected from the group consisting of a mortar composition, a cement paste composition, and a concrete composition.

11. The cementitious composition according to claim 9 , wherein the water to cement weight ratio (w/c) is in the range of about 0.30 to 0.35.

12. The cementitious composition according to claim 9 , wherein the superplasticizer and the air entraining agent are the same compound.

13. Cementitious solid obtained from hardening the cementitious composition according to claim 9 .

14. Cementitious solid according to claim 13 , selected from the group consisting of a mortar, a cement paste and a concrete.

15. The cementitious composition according to claim 9 , wherein the air entraining agent (AEA) is present at a concentration of 0.02 to 0.04 weight %, relative to the weight of the cement.

Assignees

• Yara Int Asa

Inventors

• Franke Wolfram

Classifications

• C04B28/021

  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 title

• C04B24/18

  Lignin sulfonic acid or derivatives thereof, e.g. sulfite lye · CPC title

• C04B2103/304

  Air-entrainers · CPC title

• C04B40/0039

  Premixtures of ingredients · CPC title

• C04B7/26 Primary

  from raw materials containing flue dust {, i.e. fly ash (C04B7/243 takes precedence)} · CPC title