WO1995026937A1

WO1995026937A1 - Gum rosin salt air-entraining hydraulic cement admixture, method of its use and hydraulic cement compositions containing same

Info

Publication number: WO1995026937A1
Application number: PCT/US1995/003688
Authority: WO
Inventors: Ara A. Jeknavorian
Original assignee: W.R. Grace & Co.-Conn.
Priority date: 1994-04-01
Filing date: 1995-03-24
Publication date: 1995-10-12
Also published as: AU2193795A

Abstract

An air-entrainer ('AE') admixture, method of entraining air, and cement compositions containing the admixture. The AEs are obtained by saponification of gum rosin, typically obtained from the group of trees consisting of pinus elliotti, pinus taeda, pinus caribaea, pinus palustris, pinus ponderosa, pinus halepensis, pinus brutia, pinus pinaster and pinus peuce, and comprise alkaline earth metal, aliphatic amine, alkanolamine, or alkali metal salts of gum rosin acids comprising a) from about 8 to 55 % by weight abietic acid, based on the total weight of said gum rosin acids in said AE; b) from about 0 to 35 % isopimaric acid; c) from about 0 to 15 % pimaric acid; and d) from about 10 to 65 % levo-pimaric acid. The admixtures of the invention, and the method for using them, provide air entrainment comparable to Vinsol rosin AEs at a lower dosage, greater stability of the air content in plastic concrete during mixing, lower spacing of air and fast buildup of air in low-slump concretes.

Description

GUM ROSIN SALT AIR-ENTRAINING HYDRAULIC

CEMENT ADMIXTURE, METHOD OF ITS USE AND

HYDRAULIC CEMENT COMPOSITIONS

CONTAINING SAME

Ara A. Jeknavorian

This application is a continuation-in-part of pending U.S. application Serial No. 08/221,912, filed April 1, 1994, the disclosure of which is incorporated herein by reference.

FIELD OF THE INVENTION

This invention relates to air entraining admixtures comprising salts of gum rosin, and its use in hydraulic cement compositions.

BACKGROUND OF THE INVENTION

This invention pertains to admixtures, and methods of using them, for of entraining air in hydraulic cement compositions. More particularly, this invention relates to compositions comprising gum rosin salts, and methods of their use for cement air entrainment.

Air entrainers ("AEs") are used in cement compositions to entrain air into the mix. AEs themselves do not generate air, but instead act to stabilize the existing air already present in the mix. Early AEs were animal tallow or complex hydrocarbons (oils/ greases) which had been oxidized during the manufacture of cement, and inadvertently found their way into concrete. Modern AEs are purposely added to cement compositions to produce the desired beneficial effects, which are, e.g., imparting freeze-thaw stability to the hardened cement mass; improved workability of the wet cement composition; mitigation of bleeding; and improvement in compressive strength of the hardened cement mass. While many AEs are available, those of the tall oil, or wood rosin-derived, i.e.,

Vinsol rosin, predominate. It has long been desired to obtain an alternative to these AEs that requires a smaller dosage but at the same time provides generally better and more consistent performance in cement, and with a wide variety of cements.

SUMMARY OF THE INVENTION This invention relates to cement compositions comprising a hydraulic cement binder and an AE comprising alkaline earth metal, aliphatic amine, alkanolamine, or alkali metal salts of gum rosin, typically obtained from the group of trees consisting of pinus elliotti, pinus taeda, pinus caribaea, pinus palustris, pinus ponderosa, pinus halepensis, pinus brutia, pinus pinaster and pinus peuce.

This invention further relates to a method for making a cement composition comprising adding to a hydraulic cement binder an AE comprising alkaline earth metal, aliphatic amine, alkanolamine, or alkali metal salts of gum rosin, typically obtained from the group of trees consisting of pinus elliotti, pinus taeda, pinus caribaea, pinus palustris, pinus ponderosa, pinus halepensis, pinus brutia, pinus pinaster and pinus peuce.

This invention further relates to a cement composition comprising a hydraulic cement binder and an AE comprising alkaline earth metal, aliphatic amine, alkanolamine, or alkali metal salts of gum rosin acids comprising a) from about 8 to 55% by weight abietic acid, based on the total weight of said gum rosin acids in said AE; b) from about 0 to 35% isopimaric acid; c) from about 0 to 15% pimaric acid; and d) from about 10 to 65% Zeuo-pimaric acid.

This invention further relates to a method for making a cement composition comprising adding to a hydraulic cement binder an AE comprising alkaline earth metal, aliphatic amine, alkanolamine, or alkali metal salts of gum rosin acids comprising a) from about 8 to 55% by weight abietic acid, based on the total weight of said gum rosin acids in said AE; b) from about 0 to 35% isopimaric acid; c) from about 0 to 15% pimaric acid; and d) from about 10 to 65% Zeuo-pimaric acid.

D E S C R I P T I O N O F T H E I N V E N T I O N

The term "cement composition" as used herein refers to pastes, mortars and concrete compositions comprising a hydraulic cement binder. The above terms are terms of art. Pastes are mixtures composed of a hydraulic cement binder, for example, Portland cement, either alone or in combination with fly ash, silica fume or blast furnace slag, and water; mortars are pastes additionally including fine aggregate, and concretes are mortars additionally including coarse aggregate. Such compositions may additionally include other admixtures such as defoaming agents, set retarders, water reducing agents, superplasticizers, and other components known to those in the art for altering properties of the composition. The cement compositions of this invention are formed by mixing required amounts of certain materials, e.g., a hydraulic cement, water, and fine or coarse aggregate, as may be applicable for the particular cement composition being formed.

The AEs of the invention comprise alkaline earth metal, aliphatic amine, alkanolamine, or alkali metal salts of gum rosin, typically obtained from the group of trees consisting of pinus elliotti, pinus taeda, pinus caribaea, pinus palustris, pinus ponderosa, pinus halepensis, pinus brutia, pinus pinaster and pinus peuce. The gum rosin preferably has the following characteristics: an acid number in the range of 150-200, a rosin content of 70-95%, and a resin content of 85-98%. These gum rosin-based AEs have surprisingly been found to provide beneficial results at lower dosages in comparison to wood rosin AEs, greater stability of the air content in plastic concrete during mixing, lower spacing of air, and faster build up of air in low-slump concretes.

AEs of the invention comprise alkaline earth metal, aliphatic amine, alkanolamine, or alkali metal salts of gum rosin acids comprising a) from about 8 to 55% by weight abietic acid, based on the total weight of said gum rosin acids in said AE; b) from about 0 to 35% isopimaric acid; c) from about 0 to 15% pimaric acid; and d) from about 10 to 65% Zeuo-pimaric acid. A preferred embodiment comprises a) from about 12 to 40% abietic acid; b) from about 5 to 22% isopimaric acid; c) from about 0 to 10% pimaric acid; and d) from about 15 to 40% Zeuo-pimaric acid.

AEs of the invention may further comprise alkaline earth metal, aliphatic amine, alkanolamine, or alkali metal salts of gum rosin acids comprising e) from about 0.5 to 15% by weight, preferably 1 to 9%, dehydroabietic acid; f) from about 0 to 15%, preferably 3 to 12%, palustric acid; g) from about 0 to 10%, preferably 2 to 7%, dihydroabietic acid; h) from about 1 to 25%, preferably 10 to 20%, neoabietic acid; and i) from about 0 to 5%, preferably 0 to 3%, tetrahydroabietic acid. A particularly preferred AE comprises alkali metal salts of the following gum rosin acids:

% (by weight) of total gum rosin acids abietic acid 15 dehydroabietic acid 5 palustric acid 7 isopimaric acid 10 dihydroabietic acid » 5 pimaric acid 10 neoabietic acid 5

Zeuo-pimaric acid 30 tetrahydroabietic acid 1 The AEs are made by saponification of the gum rosin with an alkaline earth metal, aliphatic amine, alkanolamine, or alkali metal salt, with aliphatic amine, alkanolamine, or alkali metal salts preferred, and alkali metal salts particularly preferred. The gum rosin is preferably steam-distilled, then neutralized with an alkali metal base, e.g., lithium, sodium and potassium hydroxide, with the potassium salt being particularly preferable, on a cost basis. Once the gum rosin has been thus prepared, it may be added to a cement composition. More preferably, it is dispersed or dissolved in a liquid carrier such as water before addition to cement. Using the admixture in this fashion is more convenient, and promotes more reproducible results. Such admixtures preferably have an AE content in the range of about 0.1% to 30%, and more preferably about 5% to 15% (percentage based on the weight of AE per total weight of solution).

The AE should be mixed into a hydraulic cement composition in an amount effective to allow the desired degree of air entrainment. The specific amount of the AE s can be readily determined and will depend on, among other things, the cement composition, and the degree of air entrainment desired. The AE may be added, generally, in percent solids on solids ("% s/s"), in the range of about 0.0008% s/s to 0.04% s/s (based on the weight of hydraulic cement binder in the cement composition), with a preferred range of about 0.0016% s/s to 0.0096% s/s, such concentrations being o generally those which provide the desired degree of air entrainment.

Use of the AEs of the invention in cement compositions results in a number of surprising benefits. For example, less of the inventive AE is needed to obtain the same benefits as currently used AEs. For example, I have found that to obtain a concrete having 5.5% air (as determined by ASTM C231), about 1.9 fluid oz./cwt of a 7.5% (by s weight) water solution of wood rosin salt ("DARAVAIR"™, Grace Construction

Products, Cambridge, Massachusetts) is needed, whereas only about 0.7 fl. oz./cwt of a 7.5% water solution of an alkali metal salt of a gum rosin is needed. Generally about 1/3 less of the AEs of the invention is required to achieve the same results as a conventional AE. 0 The AE admixtures of this invention can be added to cement compositions in any conventional manner familiar to those in the art. The admixture should be substantially uniformly mixed with the cement composition.

Before proceeding to the Examples, it can be seen from Table I, below, that the quality of air in concretes containing AEs of the invention is surprisingly improved, in 5 comparison to a wood rosin-derived AE.

T A B L E I

Concrete Concrete containing AE containing of Invention Wood rosin AE

Air Content (%) 7.40 6.14

Chord Length (in) 0.0060 0.0064

Specific Surface (1/in) 666 624

Voids/Inch 12.3 9.6

Spacing Factor (in) 0.0051 0.0065

Paste Content (%) 25.2 25.0 The following examples are given for illustrative purposes only. Unless otherwise indicated, all parts and proportions are by weight.

E X A M P L E 1

A comparison between the performance in concrete of a tall oil AE (DAREX™ II AEA, Grace Construction Products, Cambridge, Massachusetts) ("Mix No. 2") and an AE of the invention ("Mix No. 3") was done. The AE of the invention was prepared by distilling a gum rosin obtained from the group of trees consisting of pinus elliotti, pinus taeda, and pinus caribaea and steam distilling it to remove turpentine, neutralizing the residue with potassium hydroxide, then dissolving the neutralized residue in water to make an admixture having a concentration of about 7.5% total solids. The specifications of the concrete mix are shown below in Table II. The mixing was carried out in accordance with CSA Standard CAN3 A266.6-M78, §8.3, with the exception that the mixer was stopped and the concrete checked for air and slump before the addition of superplasticizer ("WRDA-19", "WRDA-20", Grace Construction Products). One can see from the data in Table III that use of the AE of the invention results in a lower air loss in plastic concrete during mixing, 1.5% compared to 3.5% for the tall oil AE. One can further see from the data that use of the AEs of the invention also promotes greater stability of the air content in plastic concrete during mixing.

T A B L E I I

Concrete Mix Proportions

"Mix No. 2" "Mix No. 3" (invention)

Cement content (kg) 310 310

Sand Content (kg) 847 847

Stone Content (kg) 1023 1023

Water (kg) 151 163

AEA (ml) 102.3 59.7

WRDA-20 (ml) 465 465

WRDA-19 (ml) 1760 1760 T A B L E I I I

Slump (mm)

"Mix No. 2" "Mix No. 3" (invention)

Before adding 70 80 superplasticizer

After adding 200 230 superplasticizer

After 30 minutes 160 180

Air Content (%)

"Mix No.2" "Mix No.3" (invention)

Before adding 9.5 9.0 superplasticizer

After adding 7.0 9.0 superplasticizer

After 30 minutes 6.0 7.8

The preceding description of the invention has been intended to illustrate rather than limit the invention. The inventors intend that various modifications or changes be made within the scope of the appended claims without departing from the spirit of the invention.

Claims

What Is Claimed Is:

1. A cement composition comprising a hydraulic cement binder and an AE comprising alkaline earth metal, aliphatic amine, alkanolamine, or alkali metal salts of gum rosin.

2. The cement composition of claim 1 wherein said gum rosin is obtained from the group of trees consisting of pinus elliotti, pinus taeda, pinus caribaea, pinus palustris, pinus ponderosa, pinus halepensis, pinus brutia, pinus pinaster and pinus peuce.

3. The cement composition of claim 1 wherein said AE is present in said cement composition in a range of about 0.0008% s/s to 0.04% s/s (based on the weight of said hydraulic cement binder in said cement composition).

4. The cement composition of claim 1 wherein said AE is present in a range of about 0.0016% s/s to 0.0096% s/s (based on the weight of said hydraulic cement binder in said cement composition).

5. The cement composition of claim 1 wherein said salts are alkali metal salts.

6. The cement composition of claim 5 wherein said alkali metal is lithium, potassium, or sodium.

7. A method for making a cement composition comprising adding to a hydraulic cement binder an AE comprising alkaline earth metal, aliphatic amine, alkanolamine, or alkali metal salts of gum rosin.

8. The method of claim 7 wherein said gum rosin is obtained from the group of trees consisting of pinus elliotti, pinus taeda, pinus caribaea, pinus palustris, pinus ponderosa, pinus halepensis, pinus brutia, pinus pinaster and pinus peuce.

9. The method of claim 7 wherein said AE is present in said cement composition in a range of about 0.0008% s/s to 0.04% s/s (based on the weight of said hydraulic cement binder in said cement composition).

10. The method of claim 7 wherein said AE is present in said cement composition in a range of about 0.0016% s/s to 0.0096% s/s (based on the weight of said hydraulic cement binder in said cement composition).

11. The method of claim 7 wherein said salts are alkali metal salts.

12. The method of claim 11 wherein said alkali metal is lithium, potassium, or sodium.

13. A cement composition comprising a hydraulic cement binder and an AE comprising alkaline earth metal, aliphatic amine, alkanolamine, or alkali metal salts of gum rosin obtained from the group of trees consisting of pinus elliotti, pinus taeda, and pinus caribaea.

14. The cement composition of claim 13 wherein said AE is present in said cement composition in a range of about 0.0008% s/s to 0.04% s/s (based on the weight of said hydraulic cement binder in said cement composition).

15. The cement composition of claim 13 wherein said AE is present in a range of about 0.0016% s/s to 0.0096% s/s (based on the weight of said hydraulic cement binder in said cement composition).

16. The cement composition of claim 13 wherein said salts are alkali metal salts.

17. The cement composition of claim 16 wherein said alkali metal is lithium, potassium, or sodium.

18. A method for making a cement composition comprising adding to a hydraulic cement binder an AE comprising alkaline earth metal, aliphatic amine, alkanolamine, or alkali metal salts of gum rosin obtained from the group of trees consisting of pinus elliotti, pinus taeda, and pinus caribaea.

19. The method of claim 18 wherein said AE is present in said cement composition in a range of about 0.0008% s/s to 0.04% s/s (based on the weight of said hydraulic cement binder in said cement composition).

20. The method of claim 18 wherein said AE is present in said cement composition in a range of about 0.0016% s/s to 0.0096% s/s (based on the weight of said hydraulic cement binder in said cement composition).

21. The method of claim 18 wherein said salts are alkali metal salts.

22. The method of claim 21 wherein said alkali metal is lithium, potassium, or sodium.

23. A cement composition comprising a hydraulic cement binder and an AE comprising alkaline earth metal, aliphatic amine, alkanolamine, or alkali metal salts of gum rosin acids comprising a) from about 8 to 55% by weight abietic acid, based on the total weight of said gum rosin acids in said AE; b) from about 0 to

35% isopimaric acid; c) from about 0 to 15% pimaric acid; and d) from about 10 to 65% Zeuo-pimaric acid.

24. The cement composition of claim 23 wherein said AE comprises alkaline earth metal, aliphatic amine, alkanolamine, or alkali metal salts of gum rosin acids comprising a) from about 12 to 40% by weight abietic acid; b) from about 5 to 22% isopimaric acid; c) from 0 to 10% pimaric acid; and d) from about 15 to 40% levo- pimaric acid.

25. The cement composition of claim 23 wherein said AE further comprises alkaline earth metal, aliphatic amine, alkanolamine, or alkali metal salts of gum rosin acids comprising e) from about 0.5 to 15% by weight dehydroabietic acid; f) from about 0 to 15% by weight palustric acid; g) from about 0 to 10% by weight dihydroabietic acid; h) from about 1 to 25% by weight neoabietic acid; and i) from about 0 to 5% by weight tetrahydroabietic acid.

26. The cement composition of claim 23 wherein said AE further comprises alkaline earth metal, aliphatic amine, alkanolamine, or alkali metal salts of gum rosin acids comprising e) from about 1 to 9% by weight, dehydroabietic acid; f) from about 3 to 12% palustric acid; g) from about 2 to 7% dihydroabietic acid; h) from about 10 to 20% neoabietic acid; and i) from about 0 to 3% tetrahydroabietic acid.

27. The cement composition of claim 23 wherein said AE is present in said cement composition in a range of about 0.0008% s/s to 0.04% s/s (based on the weight of said hydraulic cement binder in said cement composition).

28. The cement composition of claim 23 wherein said AE is present in a range of about 0.0016% s/s to 0.0096% s/s (based on the weight of said hydraulic cement binder in said cement composition).

29. The method of claim 23 wherein said salts are alkali metal salts.

30. The cement composition of claim 29 wherein said alkali metal is lithium, potassium, or sodium.

31. A method for making a cement composition comprising adding to a hydraulic cement binder an AE comprising alkaline earth metal, aliphatic amine, alkanolamine, or alkali metal salts of gum rosin acids comprising a) from about 8 to 55% by weight abietic acid, based on the total weight of said gum rosin acids in said AE; b) from about 0 to 35% isopimaric acid; c) from about 0 to 15% pimaric acid; and d) from about 10 to 65% Zeuo-pimaric acid.

32. The method of claim 31 wherein said salts of said gum rosin acids comprise a) from about 12 to 40% by weight abietic acid; b) from about 5 to 22% isopimaric acid; c) from 0 to 10% pimaric acid; and d) from about 15 to 40% Zrøo-pimaric acid.

33. The method of claim 31 wherein said AE further comprises alkaline earth metal, aliphatic amihe, alkanolamine, or alkali metal salts of gum rosin acids comprising e) from about 0.5 to 15% by weight dehydroabietic acid; f) from about 0 to 15% by weight palustric acid; g) from about 0 to 10% by weight dihydroabietic acid; h) from about 1 to 25% by weight neoabietic acid; and i) from about 0 to 5% by weight tetrahydroabietic acid.

34. The method of claim 31 wherein said AE further comprises alkaline earth metal, aliphatic amine, alkanolamine, or alkali metal salts of gum rosin acids comprising e) from about 1 to 9% by weight, dehydroabietic acid; f) from about 3 to 12% palustric acid; g) from about 2 to 7% dihydroabietic acid; h) from about 10 to 20% neoabietic acid; and i) from about 0 to 3% tetrahydroabietic acid.

35. The method of claim 31 wherein said AE is present in said cement composition in a range of about 0.0008% s/s to 0.04% s/s (based on the weight of said hydraulic cement binder in said cement composition).

36. The method of claim 31 wherein said AE is present in said cement composition in a range of about 0.0016% s/s to 0.0096% s/s (based on the weight of said hydraulic cement binder in said cement composition).

37. The method of claim 31 wherein said AE further comprises alkaline earth metal, aliphatic amine, alkanolamine, or alkali metal salts of gum rosin acids comprising e) from about 0.5 to 15% by weight dehydroabietic acid; f) from about 0 to 15% by weight palustric acid; g) from about 0 to 10% by weight dihydroabietic acid; h) from about 1 to 25% by weight neoabietic acid; and i) from about 0 to 5% by weight tetrahydroabietic acid.

38. The method of claim 31 wherein said salts are alkali metal salts.

39. The method of claim 38 wherein the alkali metal is lithium, potassium, or sodium.