Hazing control for carbonatable calcium silicate-based cements and concretes

Patent metadata

Field	Value
Publication number	US-2017260096-A1
Application number	US-201715451344-A
Country	US
Kind code	A1
Filing date	Mar 6, 2017
Priority date	Mar 11, 2016
Publication date	Sep 14, 2017
Grant date	—

Abstract

The invention provides novel methods and compositions that mitigate the occurrence of hazing of products made from carbonatable calcium silicate-based cements. The methods and compositions of the invention may be applied in a variety of cement and concrete components in the infrastructure, construction, pavement and landscaping industries.

First claim

1 . A method for mitigating or reducing hazing on a concrete product, comprising:
prior to curing cement to form a concrete product, adding to the concrete mixture an admixture comprising one or more components capable of reacting with one or more of soluble alkali, alkaline earth, sulfate or chloride ions to form a low solubility material.

2 . The method of claim 1 , further comprising:
curing the cement to form a concrete product.

3 . The method of claim 1 , wherein adding to cement an admixture comprises adding a solid admixture.

4 . The method of claim 1 , wherein adding to cement an admixture comprises adding a liquid admixture.

5 . The method of claim 1 , wherein adding to cement an admixture comprises adding a solid admixture and a liquid admixture.

6 . The method of claim 1 , wherein the cement is a carbonatable calcium silicate-based cement.

7 . The method of claim 6 , wherein the carbonatable calcium silicate-based cement comprises calcium silicate and one or more discrete calcium silicate phases selected from CS (wollastonite or pseudowollastonite), C3S2 (rankinite), C2S (belite, larnite, bredigite), and an amorphous calcium silicate phase at about 30% or more by mass of the total phases.

8 . The method of claim 6 , wherein in the carbonatable calcium silicate-based cement elemental Ca and elemental Si are present in the composition at a molar ratio from about 0.8 to about 1.2 and metal oxides of Al, Fe and Mg are present in the composition at about 30% or less by mass.

9 . The method of claim 6 , wherein the solid admixture comprises one or more selected from calcium aluminate, calcium hydroxide and calcium sulfoaluminate

10 . The method of claim 6 , wherein the solid admixture comprises ground granulated blast furnace slag (GGBFS) and/or fly ash.

11 . (canceled)

12 . (canceled)

13 . The method of claim 10 , wherein the solid admixture further comprises gypsum.

14 . The method of claim 13 , wherein the amount of GGBFS and/or Fly Ash together account for from about 1% to about 25% by weight of cement mixture, and the amount of gypsum accounts for from about 0.5% to about 10% by weight of cement mixture.

15 . The method of claim 9 , wherein the solid admixture comprises calcium aluminate and is added to the cement in an amount such that calcium aluminate accounts for about 0.1% to about 10% by weight of the cement mixture.

16 . (canceled)

17 . (canceled)

18 . The method of claim 9 , wherein the solid admixture comprises calcium sulfoaluminate.

19 . (canceled)

20 . The method of claim 9 , wherein the solid admixture comprises calcium hydroxide.

21 . The method of claim 20 , wherein the solid admixture is added to the cement in an amount such that calcium hydroxide accounts for about 0.1% to 10% by weight of the cement mixture.

22 . The method of claim 1 , wherein the liquid admixture is an aqueous solution comprising one or more highly soluble calcium salts.

23 . The method of claim 22 , wherein the highly soluble calcium is selected from calcium nitrate, calcium nitrite, and calcium chloride.

24 . The method of claim 23 , wherein the liquid admixture comprises calcium nitrate and is added to the cement at 0.5 g to 30 g calcium nitrate per kg of cement.

25 - 29 . (canceled)

30 . The method of claim 1 , wherein the alkali, alkaline earth, sulfate or chloride ions are selected from Ca 2+ , Na + , K + , Mg 2+ , Cl − , and SO 3 2− ions.

31 . The method of claim 2 , wherein curing is by CO 2 at a temperature of about 50° C. to about 70° C.

32 . The method of claim 31 , wherein during the temperature ramping period, changing the temperature of concrete at a controlled heating rate of not more than 15° C. per hour with concurrent relative humidity of greater than about 70%.

33 . (canceled)

34 . (canceled)

35 . A method for curing a cement to form a concrete product, comprising: during the temperature ramping period, changing the temperature of the uncured concrete product at a controlled heating rate of not more than 15° C. per hour with concurrent relative humidity of greater than about 70%.

36 . (canceled)

37 . (canceled)

38 . The method of claim 35 , wherein the cement is a carbonatable calcium silicate-based cement.

39 . The method of claim 38 , wherein the carbonatable calcium silicate-based cement comprises calcium silicate and one or more discrete calcium silicate phases selected from CS (wollastonite or pseudowollastonite), C3S2 (rankinite), C2S (belite, larnite, bredigite), and an amorphous calcium silicate phase at about 30% or more by mass of the total phases.

40 . The method of claim 39 , wherein in the carbonatable calcium silicate-based cement elemental Ca and elemental Si are present in the composition at a molar ratio from about 0.8 to about 1.2 and metal oxides of Al, Fe and Mg are present in the composition at about 30% or less by mass.

41 . A carbonatable composition, comprising:
calcium silicate; one or more discrete calcium silicate phases selected from CS (wollastonite or pseudowollastonite), C3S2 (rankinite), C2S (belite, larnite, bredigite), and an amorphous calcium silicate phase at about 30% or more by mass of the total phases; and calcium aluminate accounting for about 0.1% to about 2.5% by weight of the carbonatable composition,
wherein
elemental Ca and elemental Si are present in the composition at a molar ratio from about 0.8 to about 1.2; and metal oxides of Al, Fe and Mg are present in the composition at about 30% or less by mass,

wherein the composition is suitable for carbonation with CO 2 at a temperature of about 30° C. to about 90° C. to form CaCO 3 with a mass gain of about 10% or more.

42 . The carbonatable composition of claim 41 , comprising one or more residual SiO 2 and CaO phases.

43 . The carbonatable composition of claim 41 , comprising one or more melilite type phases having the general formula (Ca,Na,K) 2 [(Mg, Fe 2+ ,Fe 3+ ,Al,Si) 3 O 7 ] or ferrite type phases having the general formula Ca 2 (Al,Fe 3+ ) 2 O 5 .

44 . The carbonatable composition of claim 41 , comprising about 20% or less of metal oxides of Al, Fe and Mg by total oxide mass.

45 . The carbonatable composition of claim 41 , wherein the reactive phases are present at about 50% or more by mass.

Assignees

• Solidia Technologies Inc

Inventors

• Sahu Sadananda
• Hennessy Rukyah
• Quinn Sean

Classifications

• C04B40/0039 Primary

  Premixtures of ingredients · CPC title

• Y02P40/18

  Carbon capture and storage [CCS] · CPC title

• C04B2111/21

  Efflorescence resistance · CPC title

• C04B28/188

  the Ca-silicates being present in the starting mixture · CPC title

• C04B2111/00019

  Carbon dioxide sequestration · CPC title