U.S. patent application number 13/849085 was filed with the patent office on 2013-08-22 for robust air-detraining for cement milling.
The applicant listed for this patent is Josephine Cheung. Invention is credited to Josephine Cheung.
Application Number | 20130213272 13/849085 |
Document ID | / |
Family ID | 43607283 |
Filed Date | 2013-08-22 |
United States Patent
Application |
20130213272 |
Kind Code |
A1 |
Cheung; Josephine |
August 22, 2013 |
Robust Air-Detraining for Cement Milling
Abstract
The present invention discloses compositions and methods wherein
air entrained in cementitious materials at least one air-entraining
cement additive is detrained using an ethoxylated, propoxylated
fatty alcohol or alkylphenol having robustness for withstanding the
harsh temperature and mechanical shearing effects of cement
grinding mills. Exemplary air-entraining cement additives include a
tertiary alkanolamine, a lignosulfonic acid or salt thereof,
naphthalene sulfonate formaldehyde condensate, melamine sulfonate
formaldehyde condensate, a glycol, a glycerin, or mixtures
thereof.
Inventors: |
Cheung; Josephine;
(Lexington, MA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Cheung; Josephine |
Lexington |
MA |
US |
|
|
Family ID: |
43607283 |
Appl. No.: |
13/849085 |
Filed: |
March 22, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13389624 |
Feb 9, 2012 |
8460457 |
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PCT/US2010/044524 |
Aug 5, 2010 |
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13849085 |
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61235580 |
Aug 20, 2009 |
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Current U.S.
Class: |
106/678 ;
106/499; 106/501.1; 106/503; 106/677 |
Current CPC
Class: |
C04B 28/04 20130101;
C04B 40/0039 20130101; C04B 40/0039 20130101; C04B 40/0039
20130101; C04B 7/52 20130101; C04B 28/04 20130101; C04B 24/121
20130101; C04B 28/04 20130101; C04B 40/0039 20130101; C04B 24/026
20130101; C04B 24/226 20130101; C04B 24/122 20130101; C04B 28/04
20130101; C04B 2103/304 20130101; C04B 24/223 20130101; C04B 24/122
20130101; C04B 24/02 20130101; C04B 24/18 20130101; C04B 24/18
20130101; C04B 24/226 20130101; C04B 24/122 20130101; C04B 24/223
20130101; C04B 24/18 20130101; C04B 24/02 20130101; C04B 24/122
20130101; C04B 2103/304 20130101; C04B 24/026 20130101; C04B 24/226
20130101; C04B 24/223 20130101; C04B 2103/52 20130101; C04B 2103/52
20130101; C04B 24/226 20130101; C04B 24/18 20130101; C04B 24/223
20130101; C04B 2103/304 20130101 |
Class at
Publication: |
106/678 ;
106/503; 106/499; 106/501.1; 106/677 |
International
Class: |
C04B 24/12 20060101
C04B024/12 |
Claims
1. (canceled)
2. (canceled)
3. (canceled)
4. (canceled)
5. (canceled)
6. (canceled)
7. (canceled)
8. (canceled)
9. (canceled)
10. (canceled)
11. (canceled)
12. An additive composition for modifying a hydratable cementitious
binder material, comprising: a homogenous aqueous liquid solution
comprising (a) at least one air-entraining cement additive in an
amount of at least 5% to no more than 95% by weight of total solids
within said solution, the at least one air-entraining cement
additive comprising a tertiary alkanolamine, a lignosulfonic acid
or salt thereof, naphthalene sulfonate formaldehyde condensate,
melamine sulfonate formaldehyde condensate, a glycol, a glycerin,
or mixtures thereof; (b) an air-detraining ethoxylated,
propoxylated fatty alcohol or alkylphenol represented by formula
(I) or (II):
CH.sub.3(CH.sub.2).sub.xCH.sub.2--O(CH.sub.2CH.sub.2O).sub.n(CH.sub.2CH(C-
H.sub.3)O).sub.mH (I)
R.sup.1--R.sup.2--O(CH.sub.2CH.sub.2O).sub.n(CH.sub.2CH(CH.sub.3)O).sub.m-
H (II) wherein x represents an integer of=2-18; n and m each
represent an integer of 3 to 15; R.sup.1 represents an alkyl group
having 4 to 12 carbons; and R.sup.2 represents a benzene ring; the
at least one tertiary alkanolamine and said ethoxylated,
propoxylated fatty alcohol or alkylphenol (both hereinafter EPFA)
being present by weight within the ratio (tertiary
alkanolamine:EPFA) of 19:1 to 1:1 by dry solids weight; and (c)
water in the amount of 10%-50% by total weight of the homogenous
aqueous liquid solution.
13. The additive composition of claim 12 wherein the at least one
at least one air-entraining cement additive is a tertiary
alkanolamine selected from the group consisting of triethanolamine,
triisopropanolamine, diethanol isopropanolamine, ethanol
diisopropanolamine, tetra(hydroxyethyl) ethylene diamine,
tetra(hydroxypropyl) ethylene diamine, methyl diethanolamine, or
mixtures thereof.
14. The additive composition of claim 12 further comprising a
cement additive selected from the group consisting of a
non-tertiary alkanolamine, a chloride salt, a sugar or
carbohydrate, a nitrite, a nitrate, a thiocyanate, a water reducer,
or mixtures thereof.
15. The additive composition of claim 12 wherein the at least one
air-entraining cement additive is triisopropanolamine.
16. A cementitious composition comprising a hydratable cementitious
binder material and the additive of claim 12.
17. The cementitious composition of claim 15 wherein the hydratable
cementitious binder material contains Portland cement ground from
clinker having at least 4% C.sub.4AF by weight of clinker and the
at least one air-entraining cement additive is present in an amount
of 0.0005% to 0.2% by weight of the hydratable cementitious binder
material.
18. The composition of claim 17 wherein the hydratable cementitious
binder material further comprises a filler or cement substitute in
the amount of 5%-75% based on dry weight of the hydratable cement,
the filler or cement substitute being selected from the group
consisting of fly ash, granulated blast furnace slag, limestone,
natural or artificial pozzolan, or mixtures thereof.
19. (canceled)
20. The composition of claim 12 wherein R.sup.1 represents a linear
C.sub.9H.sub.19 group.
Description
FIELD OF THE INVENTION
[0001] This invention relates to additives for hydratable cement,
and more particularly to the use of certain air-entraining cement
additive or additives and an ethoxylated, propoxylated fatty
alcohol or alkylphenol for detraining air produced by the
air-entraining cement additive or additives in cement grinding.
BACKGROUND OF THE INVENTION
[0002] U.S. Pat. Nos. 4,943,323, 5,017,234, and 5,084,103 and EP
0415799B1 of Gartner et al. disclosed the use of
triisopropanolamine (hereinafter "TIPA") for enhancing the late day
strength (e.g., at 7- and 28-days) of cement and blended cement.
This additive could be admixed with cement powder or interground as
an addition with cement clinker during finish milling.
[0003] The term "cement" is used to refer to a binder material
that, when mixed with water, forms a paste that hardens slowly to
form rock-hard products such as mortar or concrete. Portland cement
is distinguished from other cements by the different components of
which it is composed, and the requirement that it meet particular
standard specifications established in each country. For example,
in the United States, the American Society for Testing and
Materials (ASTM), American Association of State Highway and
Transportation Officials, and other government agencies have set
certain basic standards for cement which are based on principal
chemical composition requirements of the clinker and principal
physical property requirements of the final cement mix.
[0004] For purposes of this invention, the term Portland cement is
intended to include all cementitious compositions meeting the
requirements of the ASTM (as designated by ASTM Specification
C150). Portland cement is prepared by sintering a mixture of
components including calcium carbonate (as limestone), aluminum
silicate (as clay or shale), silicon dioxide (as sand) and
miscellaneous iron oxides. During sintering, chemical reactions
take place wherein hardened nodules, commonly called clinkers, are
formed. Portland cement clinker is formed by the reaction of
calcium oxide with acidic components to give primarily tricalcium
silicate, dicalcium silicate, tricalcium aluminate, and a ferrite
solid solution phase approximating tetracalcium aluminoferrite
(C.sub.4AF).
[0005] After the clinker has cooled, it is then pulverized together
with a small amount of gypsum (calcium sulfate) in a finish
grinding mill to provide a fine, homogeneous powdery product known
as Portland cement.
[0006] The term "blended cements" typically refers to a combination
of Portland cement and secondary cementitious materials. Because of
the rigid compositional and physical requirements for forming
suitable Portland cement clinker, such cement clinker becomes a
relatively expensive raw material. Thus, for certain applications,
it is possible to substitute a portion of the Portland cement with
secondary cementitious materials such as less expensive fillers or
clinker substitutes including limestone, ground granulated blast
furnace slag, fly ash, natural or artificial pozzolan, and the
like.
[0007] As used herein, the term filler typically is used to refer
to an inert material that has no later age strength enhancing
attributes.
[0008] The term "clinker substitute" refers to a material that may
contribute to long term compressive strength enhancement, but
usually exhibits little or no enhancement of 7- or 28-day
compressive strength. The addition of these fillers or clinker
substitutes to form "blended cements" is limited in practice by the
fact that such addition usually results in a diminution in the
physical strength properties of the resultant cement. For example,
when filler material such as limestone is blended with cement in
amounts greater than 5%, the resultant cement exhibits a marked
reduction in strength, particularly with respect to the strength
attained after 28 days of moist curing (28-day strength). The
28-day strength has particular significance and will be emphasized
throughout this invention since it is the strength at this age
which is most commonly used to assess the engineering properties of
the final cement products.
[0009] It was observed by Gartner et al. that the addition of
triisopropanolamine ("TIPA") to cement or blended cement, while
enhancing the later age strength of the cement, also tended to
increase the amount of air entrained in the cement (U.S. Pat. No.
4,943,323, column 6, lines 34 et seq.). Analysis of various cement
samples revealed an increase in air entrainment of about 2% when
compared to cement that did not contain TIPA. Hence, the use of an
air detraining agent or "air detrainer" was proposed for
eliminating the increased air entrainment in the cement due to the
presence of TIPA. Gartner et al. suggested that the air detrainer
should be compatible with TIPA in that the detrainer should not
degrade TIPA and that TIPA be soluble therein or made soluble by
addition of further ingredients.
[0010] Gartner et al. therefore described suitable air detraining
agents to include nonionic surfactants such as phosphates,
including tributylphosphate, phthalates including
diisodecylphthalate, and block copolymers including
polyoxypropylene-polyoxyethylene-block copolymers (U.S. Pat. No.
4,943,323, Column 6, lines 50-55). For the purpose of withstanding
the heat generated by the grinding of clinker in a cement grinding
mill, the inventors preferred using nonionic
polyoxypropylene-polyoxy-ethylene block copolymers having molecular
weight of at least 2500 (U.S. Pat. No. 4,943,323, Col. 6, lines
62-66).
[0011] In U.S. Pat. No. 5,156,679, Gartner et al. taught the use of
water-soluble alkylated alkanolamine salts for detraining air in
hydraulic cement structures, and in particular concretes. Added as
admixtures to cement, these materials included N-alkylalkanolamine
and N-alkyl-hydroxylamine. In example 1, Gartner et al.
[0012] demonstrated that when TIPA was added to a mortar mix in the
amount of 0.02% by weight as part of the water of hydration along
with 0.01% by weight of dibutylamino-2-butanol ("DBAB") as
defoaming agent, the mortar mix demonstrated a reduction in air
entrainment (Col. 5, line 51-Col. 6, line 14).
[0013] While the above-mentioned air detrainers may be suitable for
detraining air when incorporated directly into cement mortar, the
heat and humidity of the grinding mill environment, coupled with
the alkaline condition of the cement and the grinding-shearing
forces imposed by the mechanical process of the grinding, tend to
degrade the molecular structure of the defoamer, sometimes to the
point at which it begins to entrain air rather than to detrain
it.
[0014] U.S. Pat. No. 5,429,675 of Cheung et al. disclosed grinding
aid compositions for grinding clinker into hydraulic cement powder,
wherein the grinding aid comprised a mixture of at least one
alkylene glycol and particulate carbon in a weight ratio of 1:0.1
to 1:0.5. The grinding aid composition could optionally contain
alkanolamines with at least one C.sub.2-C.sub.3 hydroxyalkyl
group.
[0015] When concrete is formed, it requires mixing of the various
components such as hydraulic cement, sand, gravel, water, and
possibly chemical additives and/or admixtures to form a
substantially uniform mixture. In the course of mixing, air becomes
entrapped in the composition and much of this air remains in the
resultant cured composition in the form of air voids. If void size
is small, the mix is said to be "air entrained." In most instances,
a small amount of air entrainment is tolerated and, in certain
instances, it is desired to enhance durability to freeze/thaw
cycles in the environment. However, air entrainment in the
hydraulic cement composition is not a desirable feature as it
causes the resultant structure to have lower compressive strength
than the mixture design is capable of attaining. There is an
inverse relationship between air entrainment and compressive
strength. It is generally believed that for each volume percent of
air voids (bubbles) in a concrete mass, there exists a five percent
loss of compressive strength.
[0016] Various materials are presently used in the concrete
industry to reduce the amount of air contained in cured hydraulic
cement compositions. Conventional air-detraining agents are
generally viewed as surfactants having low hydrophilic-lipophilic
balance (HLB) values, such as tri-n-butylphosphate, n-octanol and
the like. Normally, these agents have been found difficult and
somewhat ineffective to use in commercial applications for several
reasons. Firstly, they cannot be readily introduced into dry
concrete mixes due to the difficulty in dispersing the additive
throughout the cement to provide a uniform distribution of the
small amount of agent required. Further, the conventional air
detrainers are not miscible with and, therefore, not capable of
being added with other conventional cement admixtures as such
admixtures are invariably water-based compositions. When it is
attempted to incorporate an air-detrainer into an aqueous admixture
composition, it tends to separate out and is not properly supplied
to the cement composition to be treated. "Water-dispersible"
air-detrainers were introduced in an attempt to overcome this
problem. These agents still have low HLB values and are actually
not water soluble but merely have densities close to that of water.
These agents phase-segregate and are unstable in aqueous suspension
in storage and, thus, have the same defects of prior known
air-detrainers.
[0017] Air-detraining agents are generally very powerful in their
effectiveness and, therefore, must be used in very small amounts
which must be substantially uniformly distributed throughout the
cement composition being treated. Presently known air-detraining
agents have the disadvantages of being difficult to monitor and
control in terms of dosage and distribution in cement compositions,
thus causing the composition to exhibit unwanted variation from the
desired degree of aeration (due to over or under dosage) and/or
variation in aeration within the formed structure (due to poor
distribution of agent).
[0018] Thus, a novel composition and method are required for
enhancing early and late strength (i.e., early strength=1-3 days
after water is added to the cement to initiate hydration; late
strength=7- and 28-days after water is added to the cement to
initiate hydration) in cements using at least one air-entraining
cement additive, of which TIPA is an example, while also achieving
robust air detrainment that survives the harsh cement milling
conditions and enables strength of the mortar to be preserved.
SUMMARY OF THE INVENTION
[0019] In contrast to the prior art, the present invention provides
a novel method for preparing cements, an additive composition for
preparing cements, and cementitious compositions having air
detrainment properties.
[0020] An exemplary process of the present invention for preparing
a hydratable cement, comprises: introducing to cement clinker,
before, during, or after the grinding manufacturing process whereby
the clinker is ground to produce hydratable cementitious binder
material, (a) at least one air-entraining cement additive in the
amount of 0.0005% to 0.2% based on weight of clinker being ground,
said at least one air-entraining cement additive comprising a
tertiary alkanolamine, a lignosulfonic acid or salt thereof,
naphthalene sulfonate formaldehyde condensate, melamine sulfonate
formaldehyde condensate, a glycol, a glycerin, or mixtures thereof;
and (b) an air-detraining ethoxylated, propoxylated fatty alcohol
or alkylphenol represented by formula (I) or (II):
CH.sub.3(CH.sub.2).sub.xCH.sub.2--O(CH.sub.2CH.sub.2O).sub.n(CH.sub.2CH(-
CH.sub.3)O).sub.mH (I)
R.sup.1--R.sup.2--O(CH.sub.2CH.sub.2O).sub.n(CH.sub.2CH(CH.sub.3)O).sub.-
mH (II)
wherein "x" represents an integer of=2-18; "n" and "m" each
represent an integer of 3 to 15; R.sup.1 represents an alkyl group
having 4 to 12 carbons (and preferably R.sup.1 represents a linear
C.sub.9H.sub.19 group); and R.sup.2 represents a benzene ring; said
tertiary alkanolamine and said ethoxylated, propoxylated fatty
alcohol or alkylphenol (both hereinafter referred to as "EPFA")
being employed in the ratio (tertiary alkanolamine:EPFA) of 19:1 to
1:1 by dry solids weight.
[0021] Preferably, components (a) and (b) are introduced to said
cement clinker in the form of a homogeneous aqueous liquid solution
wherein the at least one air-entraining cement additive and the
ethoxylated, propoxylated fatty alcohol or alkylphenol are
pre-mixed together uniformly within said solution. More preferably,
the homogeneous aqueous liquid solution further comprises one or
more cement additives which may include additional cement
additives. For example, the liquid solution may comprise a number
of cement-entraining additives, such as a combination of tertiary
alkanolamines (e.g., TIPA, TEA) and a glycol.
[0022] The foregoing process may be applied to cementitious
materials other than cement clinker, such as fly ash, granulated
blast furnace slag, limestone, natural or artificial pozzolan, or
mixtures thereof.
[0023] An exemplary additive of the invention for modifying a
hydratable cementitious binder material comprises: a homogenous
aqueous liquid solution comprising (a) at least one air-entraining
cement additive in the amount of 0.0005% to 0.2% based on weight of
clinker being ground, said at least one air-entraining cement
additive comprising a tertiary alkanolamine, a lignosulfonic acid
or salt thereof, naphthalene sulfonate formaldehyde condensate,
melamine sulfonate formaldehyde condensate, a glycol, a glycerin,
or mixtures thereof; and (b) an air-detraining ethoxylated,
propoxylated fatty alcohol or alkylphenol (both hereinafter
referred to as "EPFA") having the representative formula (I or II)
as described above.
[0024] The invention is also directed to hydratable cementitious
compositions resulting from use of the above-described process and
additive examples.
[0025] The term "homogeneous aqueous liquid solution," as used to
describe preferred additives of the invention, refers to a liquid
solution which is substantially clear (non-turbid) and having
essentially no discontinuous liquid phases or undissolved particles
(such as dispersed solid salt particles) within the aqueous liquid.
Cement manufacturers prefer to use clear aqueous solutions because
they do not want components to separate from liquid; they want
components dissolved and homogeneously distributed. This avoids
pumping difficulties caused by precipitates and particle
suspensions. The use of EPFA to detrain air generated by the
air-entraining cement additive component (e.g., tertiary
alkanolamine) during cement grinding is believed to be surprising
given that EPFA is essentially non-water-soluble in nature. The
miscibility of TIPA with EPFA and water thus surprisingly enables
formulation of an easily liquid-dispensed, meterable aqueous
solution. Use of aqueous solutions avoids the need for viscosity
modifying agents that can also complicate pumping.
[0026] In achieving uniformity and homogeneity in the aqueous
solution, the present invention also enables the production of
cement that is consistent throughout the production process as well
as in the mortar or concrete in which it is used.
[0027] Further advantages and benefits of the present invention are
discussed in further detail hereinafter.
BRIEF DESCRIPTION OF DRAWINGS
[0028] FIG. 1 is a graphic illustration of use in an Ordinary
Portland Cement ("OPC") of an exemplary ethoxylated, propoxylated
fatty alcohol surface active agent used in varying percentages
within an exemplary air-entraining cement additive (TI PA) as a
function of air content; and
[0029] FIG. 2 is a graphic illustration of use in another OPC
(obtained from a source different from the cement shown in FIG. 1)
of an exemplary ethoxylated, propoxylated fatty alcohol surface
active agent used in varying percentages within an additive
composition having an exemplary air-entraining cement additive (TI
PA) as a function of air content.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0030] Additive compositions of the invention comprise the use of
(A) at least one air-entraining cement additive comprising a
tertiary alkanolamine, a lignosulfonic acid or salt thereof,
naphthalene sulfonate formaldehyde condensate, melamine sulfonate
formaldehyde condensate, a glycol, a glycerin, or mixtures thereof;
and (B) an air-detraining ethoxylated, propoxylated fatty alcohol
or alkylphenol in "hydratable cementitious binder materials," a
term which may be used interchangeably with the term "cement" and
which is intended to include Portland cement, one or more secondary
cementitious materials (e.g., fly ash, granulated blast furnace
slag, limestone, natural or artificial pozzolan), or mixtures
thereof. An example of natural pozzolan is volcanic ash.
[0031] Exemplary tertiary alkanolamines suitable for use in the
invention may include triethanolamine (TEA), triisopropanolamine
(TIPA), diethanol isopropanolamine (DEIPA), ethanol
diisopropanolamine (EDIPA), tetra(hydroxyethyl) ethylene diamine
(THEED), and tetra(hydroxypropyl) ethylene diamine (THPED), methyl
diethanolamine (MDEA), and mixtures thereof.
[0032] An exemplary lignosulfonic acid or salt thereof suitable for
use in the invention includes calcium lignosulfonate, sodium
lignosulfonate, and the like.
[0033] Exemplary glycols suitable for use in the invention include
polyethylene glycol, diethylene glycol, propylene glycol,
dipropylene glycol, and mixtures thereof.
[0034] Such hydratable cementitious binder materials function, when
water is added in sufficient amount to initiate the hydration
reaction, to bind and to hold together fine aggregates (e.g., sand)
to form cement mortars, and, when coarse aggregates (e.g., crushed
gravel) are added, to form concrete.
[0035] The additives (or additive compositions) of the invention
are contemplated to be introduced before, during, or after the
grinding of cement clinker to produce finished cement and blended
cements. For example, the additives may be combined directly with
the clinker, directly with supplementary cementitious materials to
be combined with the clinker (e.g., at the fly ash plant or slag
recovery process), or otherwise introduced directly into
conventional grinding mills, such as ball mills (or tube mills).
The present inventors also believe that they can be applied in
mills employing rollers (e.g., vertical rollers, rollers on tables,
etc.). See e.g., U.S. Pat. No. 6,213,415 of Cheung.
[0036] The term "hydratable" as used herein is intended to refer to
cement or cementitious binder materials that are hardened by
chemical interaction with water. Portland cement clinker is a
partially fused mass primarily composed of hydratable calcium
silicates. The calcium silicates are essentially a mixture of
tricalcium silicate (3CaO.SiO.sub.2 "C.sub.3S" in cement chemists
notation) and dicalcium silicate (2CaO.SiO.sub.2, "C.sub.2S") in
which the former is the dominant form, with lesser amounts of
tricalcium aluminate (3CaO.Al.sub.2O.sub.3, "C.sub.3A") and
tetracalcium aluminoferrite (4CaO.Al.sub.2O.sub.3.Fe.sub.2O.sub.3,
"C.sub.4AF"). See e.g., Dodson, Vance H., Concrete Admixtures (Van
Nostrand Reinhold, New York N.Y. 1990), page 1.
[0037] As disclosed in U.S. Pat. No. 4,943,323, U.S. Pat. No.
5,017,234, U.S. Pat. No. 5,084,103 and EPO415799B1, owned by the
common assignee hereof, the use of triisopropanolamine ("TIPA"), a
tertiary alkanolamine, in an amount of 0.0005% to 0.2% by weight of
cement (e.g., the hydratable cementitious binder material that may
include Portland cement along with any secondary cementitious
materials) was shown to enhance 7- and 28-day strength of Portland
cement or blended cement having at least 4% calcium aluminoferrite
(C.sub.4AF) by weight based on total weight of cement clinker used
in grinding to provide the cement. Such late day (or late age)
enhancement of the compressive strength was particularly valuable
for use in blended cements containing limestone or other filler or
substitute components that otherwise decrease late day
strength.
[0038] The term "homogenous aqueous liquid solution" as used herein
to refer to the additive composition used for preparing cement,
means and refers to a water-based solution having essentially no
separable layers, portions, or phases, no discontinuous liquid
phases; and no undissolved solid particles dispersed within the
aqueous liquid. The components of such a homogenous aqueous liquid
solution should also be uniformly distributed in equal proportion
throughout the entire volume of the solution.
[0039] As summarized above, an exemplary process for preparing a
hydratable cement, comprises: introducing to cement clinker,
before, during, or after the grinding manufacturing process whereby
the clinker is ground to produce hydratable cementitious binder
material, (a) at least one air-entraining cement additive,
comprising a tertiary alkanolamine, a lignosulfonic acid or salt
thereof, naphthalene sulfonate formaldehyde condensate, melamine
sulfonate formaldehyde condensate, a glycol, a glycerin, or mixture
thereof, in the amount of 0.0005% to 0.2% based on weight of
clinker being ground; and (b) an air-detraining ethoxylated,
propoxylated fatty alcohol or alkylphenol represented by formula
(I) or (II):
CH.sub.3(CH.sub.2).sub.xCH.sub.2--O(CH.sub.2CH.sub.2O).sub.n(CH.sub.2CH(-
CH.sub.3)O).sub.mH (I)
R.sup.1--R.sup.2--O(CH.sub.2CH.sub.2O).sub.n(CH.sub.2CH(CH.sub.3)O).sub.-
mH (II)
wherein "x" represents an integer of=2-18; "n" and "m" each
represent an integer of 3 to 15; R.sup.1 represents an alkyl group
having 4 to 12 carbons (and preferably R.sup.1 represents a linear
C.sub.9H.sub.19 group); and R.sup.2 represents a benzene ring; said
tertiary alkanolamine and said ethoxylated, propoxylated or
alkylphenol (both hereinafter referred to as "EPFA") being employed
in the ratio (tertiary alkanolamine:EPFA) of 19:1 to 1:1 by dry
solids weight.
[0040] As mentioned in the foregoing summary section, the invention
may be applied to cementitious materials in addition to cement
clinker. Thus, a further exemplary process of the invention,
comprises: introducing to a cementitious material before, during,
or after grinding said cementitious material to produce a
hydratable cementitious binder material, said cementitious material
being selected from the group consisting of clinker, fly ash,
granulated blast furnace slag, limestone, natural or artificial
pozzolan, or mixture thereof; (a) at least one air-entraining
cement additive comprising a tertiary alkanolamine, a lignosulfonic
acid or salt thereof, naphthalene sulfonate formaldehyde
condensate, melamine sulfonate formaldehyde condensate, a glycol, a
glycerin, or mixture thereof tertiary alkanolamine, in the amount
of 0.0005% to 0.2% based on weight of cementitious material being
ground; and (b) an air-detraining ethoxylated, propoxylated fatty
alcohol or alkylphenol represented by formula (I) or (II):
CH.sub.3(CH.sub.2).sub.xCH.sub.2--O(CH.sub.2CH.sub.2O).sub.n(CH.sub.2CH(-
CH.sub.3)O).sub.mH (I)
R.sup.1--R.sup.2--O(CH.sub.2CH.sub.2O).sub.n(CH.sub.2CH(CH.sub.3)O).sub.-
mH (II)
wherein "x" represents an integer of=2-18; "n" and "m" each
represent an integer of 3 to 15; R.sup.1 represents an alkyl group
having 4 to 12 carbons (and preferably R.sup.1 represents a linear
C.sub.9H.sub.19 group); and R.sup.2 represents a benzene ring; said
tertiary alkanolamine and said ethoxylated, propoxylated fatty
alcohol or alkylphenol (both hereinafter referred to as "EPFA")
being employed in the ratio (tertiary alkanolamine:EPFA) of 19:1 to
1:1 by dry solids weight.
[0041] Hydratable cement powders is produced by this method have
lower entrained air, when water is mixed to initiate hydration of
the hydratable cementitious binder material and the hydratable
cementitious binder material is allowed to harden into a structure,
compared to hydratable cementitious binder material made with
tertiary alkanolamine but without the use of the EPFA.
[0042] An exemplary additive of the invention for modifying a
hydratable cementitious binder material, comprises: a homogenous
aqueous liquid solution comprising (a) at least one air-entraining
cement additive in the amount of 0.0005% to 0.2% based on weight of
clinker being ground, said at least one air-entraining cement
additive comprising a tertiary alkanolamine, a lignosulfonic acid
or salt thereof, naphthalene sulfonate formaldehyde condensate,
melamine sulfonate formaldehyde condensate, a glycol, a glycerin,
or mixture thereof; and (b) an air-detraining ethoxylated,
propoxylated fatty alcohol or alkylphenol (both hereinafter
referred to as "EPFA"), as previously described above.
[0043] In preferred processes and additives of the invention, the
amount of EPFA used is preferably greater than 5%, and more
preferably greater than 10%, by weight of total solids of
air-entraining cement additive (e.g., tertiary alkanolamine such as
triisopropanolamine and/or triethanolamine) being added to the
clinker. The EPFA may also be used most preferably in amounts of at
0.0005% to 20% by weight of total solids of air-entraining material
added to clinker, depending also on the nature of the cement.
[0044] Hydratable cement powder is produced having higher
compressive strength and lower entrained air, when water is mixed
to initiate hydration of the hydratable cementitious binder
material and said hydratable cementitious binder material is
allowed to harden into a structure, when compared to hydratable
cementitious binder material made with an air-entraining cement
additive (e.g., TIPA) but without the use of said EPFA.
[0045] In other exemplary embodiments, one or more conventional
cement additives may be introduced to the cement clinker, before,
during, or after the grinding manufacturing process whereby the
clinker is ground to produce hydratable cementitious binder
material, as previously discussed above. Such conventional cement
additives may include an alkanolamine other than a tertiary
alkanolamine, a chloride salt (e.g., calcium chloride, sodium
chloride), a sugar (e.g., glucose, fructose, corn syrup, molasses,
etc.) or a carbohydrate (e.g., sodium gluconate, potassium
gluconate), a nitrite (e.g., calcium nitrite, sodium nitrite), a
nitrate (e.g., calcium nitrate, sodium nitrate), a thiocyanate
(e.g., sodium thiocyanate), biodiesel production byproducts (e.g.,
bio-glycerin), or mixtures thereof.
[0046] Such further cement additives may be incorporated in the
amounts as desired (e.g., 0.0002%-0.1% by weight total solids
within the additive composition). Hence, various combinations of
TIPA with one or more other alkanolamines are contemplated within
the present invention and are believed to be benefitted by the
air-detraining effects of EPFA.
[0047] Most preferably, the TIPA and EPFA, along with optional
cement additives, are added as a single component, before, during,
or after the clinker grinding process, in the form of a homogeneous
aqueous liquid solution wherein the components are pre-mixed
together uniformly within solution.
[0048] In preferred cementitious compositions and methods of the
invention, the cement clinker employed has a tetracalcium alumino
ferrite (C.sub.4AF) content of at least 4% by weight of the cement
clinker. According to U.S. Pat. Nos. 4,943,323, 5,017,234, and
5,084,103 and EP 0415799B1 of Gartner et al., this C.sub.4AF
content enables triisopropanolamine ("TIPA") to enhance late day
strength of cements having this requisite level of C.sub.4AF. The
preferred dosage of TIPA would be 0.0005%-0.2% based on weight of
the cement clinker.
[0049] In further preferred embodiments, TIPA is combined with TEA,
DEIPA, EDIPA, THEED, and/or THPED. The preferred ranges 0.005%-0.1%
by weight total solids of each component within the additive
composition. With respect to alkanolamines such as TIPA, TEA,
DEIPA, THEED, and combinations thereof, these components may be
incorporated with the hydratable cementitious binder material
before, during, or after grinding.
[0050] While the invention is described herein using a limited
number of embodiments, these specific embodiments are not intended
to limit the scope of the invention as otherwise described and
claimed herein. Modification and variations from the described
embodiments exist. More specifically, the following examples are
given as a specific illustration of embodiments of the claimed
invention. It should be understood that the invention is not
limited to the specific details set forth in the examples. All
parts and percentages in the examples, as well as in the remainder
of the specification, are by percentage weight unless otherwise
specified.
[0051] Further, any range of numbers recited in the specification
or claims, such as that representing a particular set of
properties, units of measure, conditions, physical states or
percentages, is intended to literally incorporate expressly herein
by reference or otherwise, any number falling within such range,
including any subset of numbers within any range so recited. For
example, whenever a numerical range with a lower limit, RL, and an
upper limit RU, is disclosed, any number R falling within the range
is specifically disclosed. In particular, the following numbers R
within the range are specifically disclosed: R=RL+k*(RU-RL), where
k is a variable ranging from 1% to 100% with a 1% increment, e.g.,
k is 1%, 2%, 3%, 4%, 5%. . . . 50%, 51%, 52% . . . 95%, 96%, 97%,
98%, 99%, or 100%. Moreover, any numerical range represented by any
two values of R, as calculated above, is also specifically
disclosed.
EXAMPLE 1
Comparative Example
[0052] A comparative example was done to demonstrate that an
ethoxylated, propoxylated fatty alcohol surface active agent
(hereinafter "EPFA"), as previously described hereinabove, has
air-detraining (defoaming) capabilities when used at or above a
certain dosage with the air-entraining cement additive
triisopropanolamine ("TIPA").
[0053] A cement mortar was made using Ordinary Portland Cement
(OPC) in accordance with EN-196 (1995), and air content was
measured using a standard air cup in accordance with ASTM C-185
(2005). The composition of the OPC was determined by quantitative
x-ray diffraction to contain 65.5% alite, 8.9% belite, 8.4%
C.sub.4AF, 1.9% cubic C.sub.3A, 2.7% orthorhombic C.sub.3A, 3.1%
periclase, 1.3% portlandite, 1.0% arcanite, 3.4% calcite, 0.6%
gypsum, 2.1% plaster and 0.9% calcium sulfate anhydrite.
[0054] Another cement mortar was made using the same cement, and
TIPA was incorporated in the amount of 200 ppm by weight of the
cement and incorporated in the hydration water. The air content of
this sample was then measured using the air cup.
[0055] Further mortars were made using the same cement, and 200 ppm
of TIPA was incorporated along with varying dosages of EPFA
(commercially available as a surface active agent from Huntsman
Corporation under the tradename SURFONIC.RTM. LF-68) in the amount
of 0-50% percentage based on dry weight solids of the additive
composition being added to the mortar cement.
[0056] The results are graphically plotted in FIG. 1, wherein the
varying amounts of EPFA surfactant are plotted along the horizontal
axis against percentage of air content measured in the cement
mortar and plotted along the vertical axis. FIG. 1 indicates that
addition of 200 ppm of TIPA increased the air content of the cement
by around 2%. (The blank sample measured 5.9% air content, whereas
addition of 200 ppm of TIPA increased the air content to about
7.8%). FIG. 1 also indicates that the amount of EPFA was not
effective to detrain the air content generated by the addition of
TIPA until EPFA dosage was more than 30% by total solids.
EXAMPLE 2
Comparative Example
[0057] Another comparative example was done to demonstrate that an
ethoxylated, propoxylated fatty alcohol surface active agent
(hereinafter "EPFA") has air-detraining (defoaming) capabilities
when used at or above a certain minimum dosage with air-entraining
triisopropanolamine ("TIPA"). However, a different Ordinary
Portland Cement (OPC) was used, and the procedures described above
for Example 1 was otherwise followed. The composition of the OPC
was determined by quantitative x-ray diffraction to contain 64.1%
alite, 10.0% belite, 5.4% CAF, 8.6% cubic C.sub.3A, 2.9%
orthorhombic C.sub.3A, 2% periclase, 0.9% arcanite, 1.2% calcite
and 3.9% plaster.
[0058] The results are graphically plotted in FIG. 2, wherein the
varying amounts of EPFA surfactant are plotted along the horizontal
axis against percentage of air content measured in the cement
mortar and plotted along the vertical axis. FIG. 2 indicates that
addition of 200 ppm of TIPA increased the air content of the cement
by around 1.1%. (The blank sample measured 2.4% air content,
whereas addition of 200 ppm of TIPA increased the air content to
about 3.5%). FIG. 2 also indicates that the amount of EPFA was not
effective to detrain the air content generated by the addition of
TIPA until EPFA dosage was more than 30% by total solids.
EXAMPLE 3
[0059] The following example illustrates the surprising increase in
strength enhancement by combining TIPA with EPFA as defoamer. The
ASTM C109 method was employed to make the mortar.
[0060] The cement used to make the mortar was made using 95 parts
of Ordinary Portland Cement (Type I as specified in ASTM C-150
(1995)) clinker and 5 parts of gypsum ground in a laboratory ball
mill together with water (blank sample), with 200 ppm TIPA in
water, or with 200 ppm TIPA and 40 ppm EPFA in water. Three cement
samples were ground to a Blaine Specific Surface Area (BSA) of
360.+-.7 m.sup.2/kg. All grinds were made at 85-90 degrees Celcius
using 3325 g of clinker and 175 g of gypsum with either 0.17% water
or with a 70 weight-percent of TIPA or TIPA with EPFA.
[0061] First, it is noted that both TIPA and TIPA with EPFA as
defoamer gave similar grinding efficiency. The results are
tabulated in Table 1 below. Equal BSA was obtained in both of the
cements made with TIPA and TIPA with EPFA at equal grinding
times.
[0062] Second, when EPFA as defoamer was added into the mix or
grind, lower air was observed in the mortar. Higher resultant
densities of the mortar were also measured.
[0063] Third, at 1 day, no strength enhancement was noted with the
addition of 200 ppm of TIPA. However, when an additional 40 ppm of
EPFA was combined with the 200 ppm of TIPA, the strength of the
cement mortar increased by 1 MPa (or 7%). This result was most
likely a result of lower air-entrainment in the mortar. When TIPA
was added as a grinding additive, it was observed that 1-day
strength increased by 1.6 MPA (or 12%). When an additional 40 ppm
of EPFA was added to 200 ppm of TIPA, 1-day strength was observed
to increase by another 1.4 MPa (or 10%).
TABLE-US-00001 TABLE 1 Time ASTM C109 - 1 Day for Prism BSA Grind
Temp. Den- (m2/ (hr: (degrees Air % of sity OPC Grinds kg) min)
Celcius) (%) MPa Blank (g/cm3) Blank 353 3:00 27.6 7.4 14.0 100
2.15 Interground 364 2:15 27.2 8.1 15.6 112 2.14 200 ppm TIPA
interground 365 2:15 27.3 7.8 17.0 122 2.16 200 ppm TIPA + 40 ppm
Defoamer EPFA Blank + admixed 353 3:00 0 8.4 13.8 99 2.12 200 ppm
TIPA Blank + admixed 353 3:00 0 8.0 14.8 106 2.15 200 ppm TIPA + 40
ppm Defoamer EPCA
EXAMPLE 4
[0064] The following example is similar to Example 3 in
illustrating the surprising increase in strength enhancement by
combining TIPA with EPFA as defoamer. However, this time the EN-196
method was employed to make the mortar.
[0065] The cements used for this example were the same as those
used in Example 3 above.
[0066] Once again, when EPFA as defoamer was added into the mix or
grind, lower air was observed in the mortar, and higher resultant
densities of the mortar were also measured.
[0067] At 1 day, a slight strength enhancement was noted with the
addition of 200 ppm of TIPA. When 40 ppm of EPFA and 200 ppm of
TIPA were added, mortar strength increased 0.8 MPa. This increase
in strength was likely a result of lower air-entrainment in the
mortar. When TIPA was added as a grinding additive, it was observed
that 1-day strength increased by 3.0 MPa (or 24%). When an
additional 40 ppm of EPFA was added to 200 ppm of TIPA, 1-day
strength was observed to increase by another 2.0 MPa (or 16%).
[0068] The results are shown in Table 2 below.
TABLE-US-00002 TABLE 2 EN 196 1 Day BSA Time Temp. Den- (m2/ for
(degrees Air %/ sity OPC Grinds kg) Grind Celcius) (%) MPa Blank
(g/cm3) Blank 353 3:00 21 4.2 12.6 100 2.24 interground 364 2:15 21
5.4 15.6 124 2.28 200 ppm TIPA interground 365 2:15 21 4.2 17.6 140
2.29 200 ppm TIPA + 40 ppm Defoamer EPCA Blank + admixed 353 3:00
21 5.5 13.6 108 2.26 200 ppm TIPA Blank + admixed 353 3:00 21 4.2
14.4 114 2.27 200 ppm TIPA + 40 ppm Defoamer EPCA
[0069] The foregoing example and embodiments were present for
illustrative purposes only and not intended to limit the scope of
the invention.
* * * * *