U.S. patent application number 16/383117 was filed with the patent office on 2019-08-08 for rapid setting material for improved processing and performance of carbonating metal silicate cement.
This patent application is currently assigned to Boral IP Holdings (Australia) PTY Limited. The applicant listed for this patent is Boral IP Holdings (Australia) PTY Limited. Invention is credited to Russell L. HILL, Amitabha KUMAR.
Application Number | 20190241471 16/383117 |
Document ID | / |
Family ID | 56151183 |
Filed Date | 2019-08-08 |
United States Patent
Application |
20190241471 |
Kind Code |
A1 |
HILL; Russell L. ; et
al. |
August 8, 2019 |
RAPID SETTING MATERIAL FOR IMPROVED PROCESSING AND PERFORMANCE OF
CARBONATING METAL SILICATE CEMENT
Abstract
Cementitious compositions and methods for producing the
cementitious compositions are described herein. The methods can
include mixing a compound of the general formula
M.sub.aSi.sub.bX.sub.cO.sub.d,
M.sub.aSi.sub.bX.sub.cO.sub.d(OH).sub.e,
M.sub.aSi.sub.bX.sub.c(OH).sub.e, or
M.sub.aSi.sub.bX.sub.c(OH).sub.e, (H.sub.2O).sub.f, wherein M
comprises a metal that can react with carbon dioxide in a
carbonation reaction to form a carbonate, Si forms an oxide during
the carbonation reaction, X is an element other than M or Si, a, b,
d, e, and f are greater than zero, and c is zero or greater, with a
rapid setting hydraulic cement to produce a cementitious mixture.
The methods can further include hydrating the cementitious mixture
and carbonating the cementitious mixture. Carbonating the
cementitious mixture can occur simultaneously with hydrating the
cementitious mixture or subsequent to hydrating the cementitious
mixture. In some embodiments, the non-hydraulic cement can comprise
wollastonite. The hydraulic cement can be in an amount of from 5 wt
% to 80 wt % of the cementitious composition.
Inventors: |
HILL; Russell L.; (San
Antonio, TX) ; KUMAR; Amitabha; (San Antonio,
TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Boral IP Holdings (Australia) PTY Limited |
North Sydney |
|
AU |
|
|
Assignee: |
Boral IP Holdings (Australia) PTY
Limited
North Sydney
AU
|
Family ID: |
56151183 |
Appl. No.: |
16/383117 |
Filed: |
April 12, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14768990 |
Aug 19, 2015 |
10301217 |
|
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PCT/US2014/072142 |
Dec 23, 2014 |
|
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16383117 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
Y02P 40/18 20151101;
C04B 28/188 20130101; C04B 14/043 20130101; C04B 28/24 20130101;
C04B 22/064 20130101; C04B 28/065 20130101; C04B 28/06 20130101;
C04B 28/188 20130101; C04B 28/30 20130101; C04B 28/34 20130101;
C04B 28/14 20130101; C04B 7/32 20130101; C04B 40/0231 20130101 |
International
Class: |
C04B 22/06 20060101
C04B022/06; C04B 28/14 20060101 C04B028/14; C04B 28/34 20060101
C04B028/34; C04B 28/18 20060101 C04B028/18; C04B 28/24 20060101
C04B028/24; C04B 28/06 20060101 C04B028/06; C04B 28/30 20060101
C04B028/30 |
Claims
1-20. (canceled)
21. A cementitious composition comprising: a non-hydraulic cement
comprising a compound of the general formula
M.sub.aSi.sub.bX.sub.cO.sub.d,
M.sub.aSi.sub.bX.sub.cO.sub.d(OH).sub.e,
M.sub.aSi.sub.bX.sub.c(OH).sub.e,
M.sub.aSi.sub.bX.sub.c(OH).sub.e(H.sub.2O).sub.f, or mixtures
thereof, wherein M is an alkaline earth metal selected from the
group consisting of calcium, magnesium, and sodium; X is an element
other than M or Si; a, b, d, e, and f are greater than zero, and c
is zero or greater; and a rapid setting hydraulic cement selected
from the group consisting of calcium aluminate cement, calcium
phosphate cement, calcium sulfate hydrate cement, calcium aluminate
sulfonate cement, magnesium oxychloride cement, magnesium
oxysulfate cement, magnesium phosphate cement, and combinations
thereof.
22. The cementitious composition of claim 21, wherein the compound
is from the wollastonite group.
23. The cementitious composition of claim 21, wherein the
non-hydraulic cement includes wollastonite.
24. The cementitious composition of claim 21, wherein the
non-hydraulic cement further comprises Ca(OH).sub.2.
25. The cementitious composition of claim 21, wherein the
cementitious composition comprises 10 wt % to 75 wt % of the
hydraulic cement and 25 wt % to 90 wt % of the non-hydraulic
cement, based on the total weight of the cementitious
composition.
26. The cementitious composition of claim 21, wherein the
cementitious composition further comprises an aggregate.
27. The cementitious composition of claim 26, wherein the aggregate
comprises ash.
28. The cementitious composition of claim 26, wherein the aggregate
comprises a lightweight aggregate.
29. The cementitious composition of claim 21, wherein the
cementitious composition further comprises inorganic fibers or
organic fibers.
30. The cementitious composition of claim 29, wherein the
cementitious composition comprises polyvinyl alcohol fibers,
polypropylene fibers, polyacrylonitrile fibers, polyester fibers,
or carbon fibers.
31. A cementitious product prepared by: hydrating the cementitious
composition of claim 21; and carbonating the cementitious
composition.
32. The cementitious product of claim 31, wherein the cementitious
product has a compressive strength of at least 1000
lbs/in.sup.2.
33. A building material comprising the cementitious product of
claim 31, wherein the building material is a tile, a brick, a
paver, a panel, a synthetic stone, or an underlay.
34. A cementitious composition comprising: a non-hydraulic cement
comprising a compound from the wollastonite group, and 15 wt % to
70 wt %, based on the total weight of the cementitious composition,
of a rapid setting hydraulic cement selected from the group
consisting of calcium aluminate cement, calcium phosphate cement,
calcium sulfate hydrate cement, calcium aluminate sulfonate cement,
magnesium oxychloride cement, magnesium oxysulfate cement,
magnesium phosphate cement, and combinations thereof; and an
aggregate.
35. The cementitious composition of claim 34, wherein the
non-hydraulic cement further includes Ca(OH).sub.2.
36. The cementitious composition of claim 34, wherein the
cementitious composition further comprises inorganic fibers or
organic fibers.
37. A cementitious product prepared by: hydrating the cementitious
composition of claim 34; and carbonating the cementitious
composition; wherein the cementitious product has a compressive
strength of at least 1000 lbs/in.sup.2.
38. A cementitious product prepared by: hydrating a cementitious
composition comprising: a non-hydraulic cement comprising a
compound of the general formula M.sub.aSi.sub.bX.sub.cO.sub.d,
M.sub.aSi.sub.bX.sub.cO.sub.d(OH).sub.e,
M.sub.aSi.sub.bX.sub.c(OH).sub.e,
M.sub.aSi.sub.bX.sub.c(OH).sub.e(H.sub.2O).sub.f, or mixtures
thereof, wherein M is an alkaline earth metal selected from the
group consisting of calcium, magnesium, and sodium; X is an element
other than M or Si; a, b, d, e, and f are greater than zero, and c
is zero or greater; 10 wt % to 75 wt % of a rapid setting hydraulic
cement selected from the group consisting of calcium aluminate
cement, calcium phosphate cement, calcium sulfate hydrate cement,
calcium aluminate sulfonate cement, magnesium oxychloride cement,
magnesium oxysulfate cement, magnesium phosphate cement, and
combinations thereof; and an aggregate; and carbonating the
cementitious composition.
39. The cementitious product of claim 38, wherein the non-hydraulic
cement comprises wollastonite, and the hydraulic cement comprises
calcium sulfate hydrate cement.
40. A building material comprising the cementitious product of
claim 38, wherein the building material is a roofing tile, a
ceramic tile, or architectural stone.
Description
FIELD OF THE DISCLOSURE
[0001] This disclosure relates generally to cementitious
compositions, more particular, to the use of a rapid setting
material in carbonating metal silicate cements.
BACKGROUND OF THE DISCLOSURE
[0002] Concrete is one of the most utilized man-made materials in
the world. Concrete includes cement and an aggregate or filler.
Cements can generally be classified as non-hydraulic and hydraulic.
Typical non-hydraulic cements harden by carbonation in the presence
of carbon dioxide in the air. Hydraulic cements such as Portland
cement, on the other hand, harden through the hydration of
silicates, oxides, aluminates, aluminoferrites, and sulfates
present in the cement.
[0003] Non-hydraulic cements derived from the reaction between
carbon dioxide and silicates such as magnesium silicate and calcium
silicate have been an area of interest. For example, non-hydraulic
cements absorb large amounts of carbon dioxide as they harden,
making them an environmentally friendly choice for use in
sustainable materials. However, diffusion of carbon dioxide and
subsequent carbonation of a non-hydraulic cement may take for
example, up to 18 hours before sufficient green strength develops
in the composition. It is advantageous to be able to demold
products comprising the non-hydraulic cement quickly and recycle
the mold to production. This would mean that fewer molds would be
required and that production rates could be increased. There is a
continuing desire for cementitious compositions that are
environmentally friendly and can provide rapid green strength.
SUMMARY OF THE DISCLOSURE
[0004] Cementitious compositions and methods for producing
cementitious compositions are described herein. The cementitious
composition can comprise a product formed by mixing a non-hydraulic
cement with a rapid setting hydraulic cement to produce a
cementitious mixture, hydrating the cementitious mixture, and
carbonating the cementitious mixture. The non-hydraulic cement can
include a compound of the general formula
M.sub.aSi.sub.bX.sub.cO.sub.d,
M.sub.aSi.sub.bX.sub.cO.sub.d(OH).sub.e,
M.sub.aSi.sub.bX.sub.c(OH).sub.e, or
M.sub.aSi.sub.bX.sub.c(OH).sub.e.(H.sub.2O).sub.f, wherein M
comprises a metal that can react with carbon dioxide in a
carbonation reaction to form a carbonate, Si forms an oxide during
the carbonation reaction, and X includes an element other than M or
Si, with a rapid setting hydraulic cement to produce a cementitious
mixture. In some embodiments, a, b, d, e, and f are greater than
zero and c is zero or greater. In some embodiments, M includes an
alkaline earth metal such as calcium, magnesium, or a combination
thereof. In some embodiments, the non-hydraulic cement can comprise
wollastonite. In some embodiments, the cementitious mixture can
also include Ca(OH).sub.2, for example, in the form of
Portlandite.
[0005] The rapid setting hydraulic cement can include calcium
aluminate cement (CAC), calcium phosphate cement, calcium sulfate
hydrate, calcium aluminate sulfonated (CAS) cement, magnesium
oxychloride (MOC) cement, magnesium oxysulfate (MOS) cement,
magnesium phosphate cement, and combinations thereof. The hydraulic
cement can be in an amount of from 5 wt % to 80 wt % of the
cementitious composition.
[0006] In some embodiments, the cementitious composition has a
compressive strength of about 1,000 lbs/in.sup.2 in less than 15
minutes after hydration. In some embodiments, the cementitious
composition has a compressive strength of about 2,000 lbs/in.sup.2
in less than 60 minutes after hydration. Building materials
comprising the cementitious composition are also disclosed. These
can include a tile, a brick, a paver, a panel, a synthetic stone,
or an underlay.
[0007] Methods of making the cementitious compositions are also
described herein. The method includes mixing a compound of the
general formula M.sub.aSi.sub.bX.sub.cO.sub.d,
M.sub.aSi.sub.bX.sub.cO.sub.d(OH).sub.e,
M.sub.aSi.sub.bX.sub.c(OH).sub.e, or
M.sub.aSi.sub.bX.sub.c(OH).sub.e.(H.sub.2O).sub.f, and a rapid
setting hydraulic cement to produce a cementitious mixture. The
method further includes hydrating the cementitious mixture, and
carbonating the cementitious mixture. The cementitious mixture can
further include aggregate. In some embodiments, the cementitious
mixture can further include Ca(OH).sub.2, for example, in the form
of Portlandite. In some embodiments, the cementitious mixture can
be carbonated using carbon dioxide dissolved in water. In some
embodiments, carbonating the cementitious mixture occurs
simultaneously with hydrating the cementitious mixture. Carbonating
the cementitious mixture can occur simultaneously or subsequent to
hydrating the cementitious mixture. For example, in some
embodiments, carbonating the cementitious mixture occurs 15 minutes
to 60 minutes after hydrating the cementitious mixture. In some
embodiments, the cementitious composition may be removed from a
mold before carbonating the cementitious mixture.
DESCRIPTION OF THE DISCLOSURE
[0008] Cementitious compositions and methods for producing
cementitious compositions are described herein. The cementitious
compositions can comprise a rapid setting hydraulic cement and a
non-hydraulic cement.
[0009] "Rapid setting", as used herein, refers to a cement that can
provide green strength to a cementitious composition. Green
strength, as used herein, refers to the ability of the cementitious
composition to be handled, for example, to be demolded, before it
has completely cured without damage. Green strength allows the
unhardened cementitious composition to keep its original shape
until the composition completely cures, for example. The rapid
setting cement can be a hydraulic cement. Hydraulic cement, as used
herein, includes compositions that after combination with water,
set and harden into cement, even in the presence of excess water.
In some embodiments, a cementitious composition comprising the
rapid setting cement can be handled within about 60 minutes or
less, about 30 minutes or less, or about 15 minutes or less, of
mixing the cementitious composition with water. The rapid setting
hydraulic cement can include calcium aluminate cement (CAC),
calcium phosphate cement, calcium sulfate hydrate, calcium
aluminate sulfonate (CAS) cement, magnesium oxychloride (MOC)
cement, magnesium oxysulfate (MOS) cement, magnesium phosphate
cement, or a combination thereof.
[0010] In some embodiments, the rapid setting hydraulic cement can
include CAC. CAC is also known in the art as "aluminous cement,"
"high-alumina cement," and "Ciment fondu." CAC is a unique class of
cement that is different from ordinary portland cement (OPC),
particularly due to its chemical make-up. CAC has a high alumina
content, e.g., greater than 30 wt %. Higher purity CACs are also
commercially available in which the alumina content can be as high
as 80 wt %. Generally, several calcium aluminate compounds may be
formed during the manufacturing process of CAC. The predominant
compound formed often can be monocalcium aluminate
(CaO.Al.sub.2O.sub.3, also referred to as CA). Other calcium
aluminate and calcium silicate may be formed, as well as compounds
containing relatively high proportions of iron oxides, magnesia,
titanic, sulfates, and alkalis. Some examples of CACs that can be
used in the cementitious compositions are provided in Table 1
below. Other CAC compositions are known in the art and may be used
in the present disclosure. CAC has a high early strength gain
(upwards of 6,000 psi at 6 hours of age at 68.degree. F.).
TABLE-US-00001 TABLE 1 Some examples of CAC and their compositions
Fe.sub.2O.sub.3 + Grade Color Al.sub.2O.sub.3 CaO SiO.sub.2 FeO
TiO.sub.2 MgO Na.sub.2O K.sub.2O Standard Grey buff to 36-42 36-42
3-8 12-20 <2 ~1 ~0.1 ~0.15 low black alumina Low Light buff
48-60 36-42 3-8 1-3 <2 ~0.1 ~0.1 ~0.05 alumina, or grey to low
iron white Medium White 35-75 25-35 <0.5 <0.5 <0.05 ~0.1
<0.3 ~0.05 alumina
[0011] In some embodiments, the rapid setting hydraulic cement can
include calcium aluminate sulfonate (CAS) cement. CAS cements can
have variable compositions, but all of them contain a significant
fraction of Ye'elimite, also called Klein's salt or tetracalcium
trialuminate sulfate. CAS can also have minor amounts of phases
such as C2S, CA, C4AF, CS, CSH2, where C is CaO, S is SiO.sub.2, A
is Al.sub.2O.sub.3, F is Fe.sub.2O.sub.3, S is SO.sub.3, M is MgO,
T is TiO.sub.2 and H is H.sub.2O. CAS has a high early strength
gain (upwards of 3,400 psi at 4 hours of age at 68.degree. F.).
[0012] The rapid setting cement can include calcium fluoroaluminate
(CFA) cement. CFA can have the chemical formula
11CaO.7Al.sub.2O.sub.3.CaF.sub.2. CFA cement has a high early
strength gain (upwards of 1000 psi at 1.5 hours of age). Further,
CFA cement can obtain its green strength at an ambient temperature
of -9.4.degree. C. (15.degree. F.). Thus, CFA can be used in cold
weather.
[0013] The rapid setting cement can include calcium sulfate based
cements. Different morphological forms of calcium sulfate can be
used in various embodiments of the cementitious compositions.
Suitable examples of rapid setting calcium sulfate cements include
calcium sulfate dihydrate (gypsum), calcium sulfate hemihydrate
(stucco), and anhydrous calcium sulfate (sometimes called calcium
sulfate anhydrite). These calcium sulfate cements can be from
naturally available sources or produced industrially.
[0014] In some embodiments, the rapid setting cement can include
calcium sulfate hemihydrate (also referred to herein as stucco).
Stucco can be made from flue gas desulfurization--a byproduct of
coal combustion. Stucco reacts very rapidly to form large crystals
that could provide an internal structure or skeleton that will
provide green strength. Stucco can set very rapidly, i.e., in less
than about 5 minutes. Stucco has a high early strength gain
(upwards of about 1000 psi at 3 hours of age at 68.degree. F.).
[0015] The rapid setting cement can also include calcium phosphate
cement (CPC). CPC consist of one or more calcium orthophosphate
powders, which upon mixing with water or an aqueous solution, form
a paste that is able to set and harden primarily as hydroxyapatite.
CPA cement has a high early strength gain.
[0016] The rapid setting cement can also include magnesium
oxychloride (MOC). MOC cement is also known in the art as "Sorel"
or "magnesite". MOC cement is formed from a magnesium oxide and
magnesium chloride solution. The MOC cement can comprise
Mg(OH).sub.2, Mg.sub.2(OH).sub.3Cl.4H.sub.2O,
Mg.sub.3(OH).sub.5Cl.4H.sub.2O as the main bonding phases.
Magnesium oxychloride cement can bond to a variety of inorganic and
organic aggregates and has a high early strength.
[0017] The rapid setting cement can also include magnesium
oxysulphate (MOS). MOS cement is formed from magnesium oxide and
magnesium sulfate solution. The MOS cement can include four
oxysulfate phases at temperatures between 30 and 120.degree. C.:
5Mg(OH).sub.2.MgSO.sub.4.3H.sub.2O (5-form),
3Mg(OH).sub.2.MgSO.sub.4.8H.sub.2O (3-form),
Mg(OH).sub.2.MgSO.sub.4.5H.sub.2O, and
Mg(OH).sub.2.2MgSO.sub.4.3H.sub.2O. MOS cement has a high early
strength gain.
[0018] The rapid setting cement can also include magnesium
phosphate cement. Magnesium phosphate cement is a mixture of
magnesium oxide and phosphoric acid, which forms water-soluble
magnesium dihydrogen phosphate
[Mg(H.sub.2PO.sub.4).sub.2.nH.sub.2O] as a reaction product. Dead
burned magnesium oxide is used as the basic component, whereas
ammonium phosphates are the preferred acidic component, as either
diammonium hydrogen phosphates ((NH.sub.4).sub.2HPO.sub.4) or
ammonium dihydrogen phosphate (NH.sub.4H.sub.2PO.sub.4). Magnesium
phosphate cement has a high early strength gain (upwards of 4,000
psi at 60 minutes and up to about 7,000 psi at 120 minutes, at
68.degree. F.).
[0019] The rapid setting cement can be a blend of two or more rapid
setting cements discussed herein. The blend can modify the set
times and green strength of the cementitious compositions relative
to those embodiments using predominately or all of a single type of
rapid setting cement.
[0020] The rapid setting cement can be present in the cementitious
composition in amounts from 5% to 80% by weight of the cementitious
composition. For example, the rapid setting cement can be included
in an amount of 10 to 75 wt %, 15 to 70 wt %, or 20 to 60 wt %,
based on the weight of the cementitious composition. in some
embodiments, the rapid setting cement can be present in the
cementitious composition in an amount of 5 wt % or greater, 10 wt %
or greater, 15 wt % or greater, 20 wt % or greater, 25 wt % or
greater, 30 wt % or greater, 35 wt % or greater, 40 wt % or
greater, 45 wt % or greater, 50 wt % or greater, or 60 wt % or
greater, based on the weight. of the cementitious composition. in
some embodiments, the rapid setting cement can be present in the
cementitious composition in an amount of 80 wt % or less, 70 wt %
or less, 60 wt % or less, 55 wt % or less, 50 wt % or less, 45 wt %
or less, 35 wt % or less, 25 wt % or less. 20 wt % or less, or 15
wt % or less, based on the weight of the cementitious
composition.
[0021] The cementitious compositions can also comprise a
non-hydraulic cement. In some embodiments, the non-hydraulic cement
can include a compound having the general formula
M.sub.aSi.sub.bX.sub.cO.sub.d,
M.sub.aSi.sub.bX.sub.cO.sub.d(OH).sub.e,
M.sub.aSi.sub.bX.sub.c(OH).sub.e, or
M.sub.aSi.sub.bX.sub.c(OH).sub.e.(H.sub.2O).sub.f, wherein M
includes a metal that can react to form a carbonate, Si forms an
oxide during the carbonation reaction, and X includes an element
other than M or Si. In some embodiments, a, b, d, e, and f are
greater than zero and c is zero or greater. In some embodiments, M
can include an alkaline earth metal, such as calcium or magnesium,
an alkali metal such as sodium, and combinations thereof. In some
embodiments, X can include sodium, aluminum, iron, hydrogen, boron,
titanium, potassium, vanadium, tungsten, molybdenum, gallium,
manganese, zirconium, germanium, copper, niobium, cobalt, indium,
sulfur, phosphorous, and combinations thereof. In some embodiments,
the ratio of a:b can be from 2.5:1 to 0.167:1. In some embodiments,
d can be 3 or greater. In some embodiments, e can be 1 or
greater.
[0022] In some embodiments, the non-hydraulic cement include a
compound from the wollastonite group (CaSiO.sub.3). In some
embodiments, the non-hydraulic cement can include oshagite
(Ca.sub.4(Si.sub.3O.sub.9)(OH).sub.2), hillebrandite
(Ca.sub.2(SiO.sub.3)(OH).sub.2), nekoite
(Ca.sub.3Si.sub.6O.sub.15.7H.sub.2O), okenite
(Ca.sub.3Si.sub.6O.sub.15.6H.sub.2O), pectolite
(Ca.sub.2NaHSi.sub.3O.sub.9), xonotlite
(Ca.sub.6Si.sub.6O.sub.17(OH).sub.2), clinotobermorite c
(Ca.sub.5Si.sub.6O.sub.17.5H.sub.2O), clinotobermorite d
(Ca.sub.5Si.sub.6O.sub.17.5H.sub.2O), clinotobermorite 9 .ANG.'c
(Ca.sub.5Si.sub.6O.sub.16(OH).sub.2), clinotobermorite 9 .ANG.'d
(Ca.sub.5Si.sub.6O.sub.16(OH).sub.2), oyelite
(Ca.sub.10B.sub.2Si.sub.8O.sub.29.12.5H.sub.2O), 9 .ANG.
tobermorite (riversideite) c (Ca.sub.5Si.sub.6O.sub.16(OH).sub.2),
9 .ANG. tobermorite (riversideite) d
(Ca.sub.5Si.sub.6O.sub.16(OH).sub.2), anomalous 11 .ANG.
tobermorite c (Ca.sub.4Si.sub.6O.sub.15(OH).sub.2.5H.sub.2O),
anomalous 11 .ANG. tobermorite d
(Ca.sub.4Si.sub.6O.sub.15(OH).sub.2.5H.sub.2O), normal 11 .ANG.
tobermorite d (Ca.sub.4.5Si.sub.6O.sub.16(OH).5H.sub.2O), 14 .ANG.
tobermorite (plombierite) c
(Ca.sub.5Si.sub.6O.sub.16(OH).sub.2.7H.sub.2O), 14 .ANG.
tobermorite (plombierite) d
(Ca.sub.5Si.sub.6O.sub.16(OH).sub.2.7H.sub.2O), jennite
(Ca.sub.9Si.sub.6O.sub.18(OH).sub.6.8H.sub.2O), metajennite
(Ca.sub.9Si.sub.6O.sub.18(OH).sub.6.8H.sub.2O), fedorite
((Na,K).sub.2(Ca,Na).sub.7(Si,Al).sub.16O.sub.38(F,OH).sub.2.3.5H.sub.2O)-
, gyrolite (NaCa.sub.16Si.sub.23AlO.sub.60(OH).sub.8.14H.sub.2O),
K-phase (Ca.sub.7Si.sub.16O.sub.38(OH).sub.2), reyerite
(Na.sub.2Ca.sub.14Si.sub.22A.sub.2O.sub.58(OH).sub.8.6H.sub.2O),
truscottite (Ca.sub.14Si.sub.24O.sub.58(OH).sub.8.2H.sub.2O)),
Z-phase (Ca.sub.9Si.sub.16O.sub.40(OH).sub.2.14H.sub.2O), calcium
chondrodite g (Ca.sub.5[SiO.sub.4].sub.2(OH).sub.2), kilchoanite
(Ca.sub.6(SiO.sub.4)(Si.sub.3O.sub.10), afwillite
(Ca.sub.3(SiO.sub.3OH).sub.2.2H.sub.2O .alpha.-C.sub.2SH
Ca.sub.2(HSiO.sub.4(OH)), cuspidine h
(Ca.sub.4(F.sub.1.5(OH).sub.0.5)Si.sub.2O.sub.7), dellaite
(Ca.sub.6(Si.sub.2O.sub.7)(SiO.sub.4)(OH)), jaffeite
(Ca.sub.6[Si.sub.2O.sub.7](OH).sub.6), killalaite
(Ca.sub.6.4(H.sub.0.6Si.sub.2O.sub.7).sub.2(OH).sub.2),
poldervaartite i (Ca(Ca.sub.0.67Mn.sub.0.33)(HSiO.sub.4)(OH)),
rosenhahnite (Ca.sub.3Si.sub.3O.sub.8(OH).sub.2), suolunite
(CaSiO.sub.2.5(OH)..sub.0.5H.sub.2O), tilleyite
(Ca.sub.5Si.sub.2O.sub.7(CO.sub.3).sub.2), bicchulite
(Ca.sub.2(Al.sub.2SiO.sub.6)(OH).sub.2), fukalite
(Ca.sub.4(Si.sub.2O.sub.6)(CO.sub.3)(OH).sub.2), katoite
hydrogarnet (Ca.sub.1.46AlSi.sub.0.55O.sub.6H.sub.3.78), rustumite
(Ca.sub.10(Si.sub.2O.sub.7).sub.2(SiO.sub.4)Cl.sub.2(OH).sub.2),
scawtitem (Ca.sub.7(Si.sub.6O.sub.18)(CO.sub.3).2H.sub.2O),
stratlingite (Ca.sub.2Al.sub.2(SiO.sub.2)(OH).sub.10.2.25H.sub.2O),
forsterite (Mg.sub.2(SiO.sub.4)), andradite
(Ca.sub.3Fe.sup.3+.sub.2(SiO.sub.4).sub.3), grossular
(Ca.sub.3Al.sub.2(SiO.sub.4).sub.3), pyrope
(Mg.sub.3Al.sub.2(SiO.sub.4).sub.3), olivine
((Mg,Fe.sup.2+).sub.2(SiO.sub.4)), sphene/titanite (CaTiSiO.sub.5),
lamite (Ca.sub.2SiO.sub.4), hatrurite (alite) (Ca.sub.3SiO.sub.5),
danburite (CaB.sub.2(SiO.sub.4).sub.2), augite
((Ca,Na)(Mg,Fe,Al,Ti)(Si,Al).sub.2O.sub.6), diopside
(CaMg(Si.sub.2O.sub.6)), enstatite (Mg.sub.2Si.sub.2O.sub.6),
heden-bergite (CaFe.sup.2+Si.sub.2O.sub.6), hypersthene
(MgFe.sup.2+Si.sub.2O.sub.6), rhodonite
((Mn.sup.2+,Fe.sup.2+,Mg,Ca)SiO.sub.3), wollastonite 1A
(CaSiO.sub.3), cordierite ((Mg,Fe).sub.2Al.sub.4Si.sub.5O.sub.18),
osumilite-(Mg)
((K,Na)(Mg,Fe.sup.2+).sub.2(Al,Fe.sup.3+).sub.3(Si,Al).sub.12O.sub.30),
osumilite-(Fe)
((K,Na)(Mg,Fe.sup.2+).sub.2(Al,Fe.sup.3+).sub.3(Si,Al).sub.12O.sub.30),
pseudo-wollastonite (Ca.sub.3Si.sub.3O.sub.9), andesine
((Na,Ca)(Si,Al).sub.4O.sub.8), anorthite
(CaAl.sub.2Si.sub.2O.sub.8), bytownite
((Na,Ca)(Si,Al).sub.4O.sub.8), labradorite
((Na,Ca)(Si,Al).sub.4O.sub.8), and oligoclase
((Na,Ca)(Si,Al).sub.4O.sub.8). In some embodiments, the
non-hydraulic cement includes wollastonite. The non-hydraulic
cement can be naturally occurring or synthetically derived.
[0023] In some embodiments, the cementitious composition can
include a compound having the formula Ca(OH).sub.2. For example,
the non-hydraulic cement can include Portlandite. In some
embodiments, the non-hydraulic cement can include a combination of
Ca(OH).sub.2 and a compound of the formula
M.sub.aSi.sub.bX.sub.cO.sub.d,
M.sub.aSi.sub.bX.sub.cO.sub.d(OH).sub.e,
M.sub.aSi.sub.bX.sub.c(OH).sub.e, or
M.sub.aSi.sub.bX.sub.c(OH).sub.e.(H.sub.2O).sub.f, or mixtures
thereof.
[0024] The non-hydraulic cement can be present in the cementitious
composition in amounts from 20% to 95% by weight of the
cementitious composition. For example, the non-hydraulic cement can
be included in an amount of 25 to 90 wt %, 30 to 85 wt %, or 40 to
80 wt %, based on the weight of the cementitious composition. In
some embodiments, the non-hydraulic cement can be present in the
cementitious composition in an amount of 20 wt % or greater, 25 wt
% or greater, 30 wt % or greater, 35 wt % or greater, 40 wt % or
greater, 45 wt % or greater, 50 wt % or greater, or 60 wt % or
greater, based on the weight of the cementitious composition. In
some embodiments, the non-hydraulic cement can be present in the
cementitious composition in an amount of 95 wt % or less, 90 wt %
or less, 85 wt % or less, 80 wt % or less, 75 wt % or less, 70 wt %
or less, 60 wt % or less, 55 wt % or less, 50 wt % or less, 45 wt %
or less, 35 wt % or less, or 25 wt % or less, based on the weight
of the cementitious composition.
[0025] In some embodiments, the weight ratio of the rapid setting
cement to the non-hydraulic cement in the cementitious composition
can be 4:1 to 1:20. For example, the ratio of the rapid setting
cement to the non-hydraulic cement in the cementitious composition
can be 2:1 to 1:15 or 1:1 to 1:10. In some embodiments, the ratio
of the rapid setting cement to the non-hydraulic cement in the
cementitious composition can be 1:20 or less, 1:15 or less, 1:10 or
less, 1:5 or less, or 1:2 or less. In some embodiments, the ratio
of the rapid setting cement to the non-hydraulic cement in the
cementitious composition can be 2:1 or greater, 1:1 or greater, 1:3
or greater, 1:5 or greater, 1:10 or greater, or 1:15 or
greater.
[0026] One or more aggregates or fillers can be further used in the
cementitious compositions described herein. In some examples, the
aggregate includes lightweight aggregate. Examples of suitable
lightweight aggregate includes fly ash, bottom ash, expanded clay,
expanded shale, expanded perlite, vermiculite, volcanic tuff,
pumice, hollow ceramic spheres, hollow plastic spheres, expanded
plastic beads (e.g., polystyrene beads), ground tire rubber, and
mixtures of these. Further examples of suitable aggregates and
fillers include other types of ash such as those produced by firing
fuels including industrial gases, petroleum coke, petroleum
products, municipal solid waste, paper sludge, wood, sawdust,
refuse derived fuels, switchgrass, or other biomass material;
ground/recycled glass (e.g., window or bottle glass); milled glass;
glass spheres; glass flakes; activated carbon; calcium carbonate;
aluminum trihydrate (ATH); silica; sand; alluvial sand; natural
river sand; ground sand; crushed granite; crushed limestone; silica
fume; slate dust; crusher fines; amorphous carbon (e.g., carbon
black); clays (e.g., kaolin); alumina; granite; calcium oxide;
calcium hydroxide; antimony trioxide; barium sulfate; magnesium
oxide; titanium dioxide; zinc carbonate; zinc oxide; syenite;
diatomite; pyrophillite; flue gas desulfurization (FGD) material;
soda ash; trona; soy meal; pulverized foam; and mixtures
thereof.
[0027] In some embodiments, inorganic fibers or organic fibers can
be included in the inorganic polymer compositions, e.g., to provide
increased strength. Fibers suitable for use with the cementitious
compositions can include glass fibers, polyvinyl alcohol (PVA)
fibers, polypropylene fibers, polyacrylonitrile fibers, polyester
fibers, carbon fibers, basalt fibers, mineral fibers, and natural
fibers (e.g., bamboo, jute, cellulose fibers, or coconut fibers).
The fibers can be included in an amount of 0.1% to 10% based on the
weight of cementitious compositions. For example, the fibers can be
included in an amount of 0.5% to 8%, 0.75% to 6%, or 1% to 4% based
on the weight of cementitious compositions. In some embodiments,
the fibers are provided in an amount of 2% or less by weight, based
on the weight of the cementitious composition including
aggregate.
[0028] The aggregate or filler can be added to the composition at a
weight ratio of 0.5:1 to 4:1 based on the weight of the
non-hydraulic cement. In some embodiments, the aggregate to
non-hydraulic cement weight ratio can be from 0.5:1 to 2.5:1 or
from 1:1 to 2:1 depending on the product to be produced. In some
embodiments, the aggregate to non-hydraulic cement weight ratio can
be 0.5:1, 1:1, 1.5:1, 2:1, 2.5:1, 3:1, 3.5:1, or 4:1.
[0029] Pigments or dyes can optionally be added to the compositions
described herein. An example of a pigment is iron oxide, which can
be added in amounts ranging from 1 wt % to 7 wt % or 2 wt % to 6 wt
%, based on the weight of cementitious composition.
[0030] The inclusion of aggregate or filler in the cementitious
compositions described herein can modify and/or improve the
chemical and mechanical properties of the compositions. For
example, the optimization of various properties of the compositions
allows their use in building materials and other structural
applications. High aggregate and filler loading levels can be used
in combination with the compositions without a substantial
reduction of (and potentially an improvement in) the intrinsic
structural and physical properties of the cementitious
compositions. Further, the use of lightweight aggregate provides
lightweight building products without compromising the mechanical
properties of the cementitious compositions.
[0031] Methods for preparing the cementitious compositions are also
described herein. Methods for providing early green strength to a
non-hydraulic cement are also described. The setting and hardening
properties of the cementitious composition can be derived from
hydrating and carbonating the cementitious mixture. In some
embodiments, the methods can include mixing the non-hydraulic
cement with a rapid setting hydraulic cement to produce a
cementitious mixture.
[0032] Mixing can be conducted in a mixing apparatus such as a high
speed mixer or an extruder. The cementitious mixture can be mixed
from 2 seconds to 30 minutes. In some examples, the cementitious
mixture is mixed for a period of 15 seconds or less (e.g., 2 to 10
or 4 to 10 seconds). The mixing times, even in the order of 15
seconds or less, result in a homogenous mixture. In some
embodiments, the cementitious mixture can be mixed for longer than
30 minutes.
[0033] The method of making the cementitious composition can
further include hydrating the cementitious mixture and carbonating
the cementitious mixture. The method may also include extruding the
cementitious mixture into a mold, for example, in a shaping mold,
compacting (including shaking or vibrating) the cementitious
mixture, and allowing the cementitious mixture to set. The method
can also include removing the cementitious mixture from a mold. The
cementitious mixture can have a set time in the mold, for example,
of from 1 to 300 minutes. In some embodiments, the set time of the
cementitious composition and the time at which the cementitious
composition can be remolded can be 60 minutes or less, 30 minutes
or less, or 15 minutes or less.
[0034] Hydrating the cementitious mixture can include mixing water
into the cementitious mixture and reaction of the hydraulic cement
with the water. The amount of water added to the cementitious
mixture during hydration depends on the needs of the individual
materials present in the mixture. The weight ratio of water to
hydraulic cement can be from 0.1:1 to 5:1, depending on the
hydraulic cement being used and the method being used for producing
the composition. The water present in the cementitious mixture can
be a significantly more than the theoretical maximum uptake.
[0035] In some embodiments, hydrating the cementitious composition
can be conducted at pH greater than 7. For example, the
cementitious mixture can be hydrated at pH 7.5 or greater, pH 8 or
greater, pH 8.5 or greater, or pH 9 or greater. in some
embodiments, there can be local variations of the pH in the
cementitious composition.
[0036] The cementitious mixture can be hydrated before extruding
and/or compacting the cementitious mixture in the mold. In some
embodiments, the cementitious mixture can be hydrated in the mold
during or at least directly after compaction or both during and
continuing after compaction.
[0037] The cementitious mixture can be combined with a water
soluble material or an organic/solvent soluble material such as a
wax that can facilitate the shaping of the cementitious mixture in
the mold. The water or solvent soluble material can then be
recovered when the cementitious composition is carbonated to create
a designed or controlled void space in the composition.
[0038] The consistency of the cementitious mixture can range from
wet cast concrete, which can be self-leveling with or without
compaction or vibration, to dry cast concrete where compaction or
vibration can be used for consolidation. An ultrasonic or
mechanical vibrating device can be used for enhanced consolidation
of the various components of the cementitious mixture in the mold.
The vibrating device useful in the preparation of compositions
described herein can be attached to or adjacent to an extruder
and/or mixer. For example, the vibrating device can be attached to
a die or nozzle or to the exit port of an extruder or mixer.
Alternatively, the vibrating device can be attached to the mold to
facilitate consolidation.
[0039] Carbonating the cementitious composition can include mixing
carbon dioxide into the cementitious mixture to produce reaction of
the non-hydraulic cement with the carbon dioxide. The source of
carbon dioxide may be from any convenient source. The carbon
dioxide can be provided as a solid (e.g., dry ice), liquid, or gas.
In some embodiments, carbon dioxide can be provided from the air or
from a gaseous carbon dioxide stream. In some embodiments, carbon
dioxide can be provided as carbon dioxide dissolved in water. In
some embodiments, the carbon dioxide used for carbonation can be
sequestered from carbon dioxide waste streams or from a product of
an industrial plant. Industrial plants that that produce carbon
dioxide as a byproduct include power plants, chemical processing
plants, steel mills, paper mills, cement plants, and other
industrial plants. For example, carbon dioxide is produced during
the production of flue gases from power plants or during combustion
of fuels. The gaseous stream may be substantially pure carbon
dioxide or a multi-component gaseous stream that includes carbon
dioxide and one or more additional gases. In some embodiments, the
carbon dioxide stream can include syngas, shifted syngas, natural
gas, hydrogen, flue gases, and the like. In some embodiments, the
carbon dioxide is provided as an alkaline solution charged with
carbon dioxide.
[0040] In some embodiments, carbonating the cementitious
composition can be conducted at pH less than 7. For example, the
cementitious mixture can be carbonated at pH 6.5 or less, pH 6 or
less, pH 5.5 or less, or pH 5 or less.
[0041] The amount of carbon dioxide added to the cementitious
mixture during carbonation depends on the needs of the individual
materials present in the mixture. In some embodiments, the carbon
dioxide present in the cementitious mixture can be in an amount
such that the molar ratio of carbon dioxide to the metal M (metal
that can react to form a carbonate such as calcium) can be 1:1 to
5:1. For example, the molar ratio of carbon dioxide to metal M can
be 5:1 or less, 4.5:1 or less, 4:1 or less, 3.5:1 or less, 3:1 or
less, 2.5:1 or less, 2:1 or less, or 1.5:1 or less. In some
embodiments, the molar ratio of carbon dioxide to metal M can be
1:1 or greater, 1.5:1 or greater, 2:1 or greater, 2.5:1 or greater,
or 3:1 or greater. The carbon dioxide present in the cementitious
mixture can be a significantly more than the theoretical maximum
uptake.
[0042] In some embodiments, mixing the carbon dioxide into the
cementitious composition occurs before the reaction of the carbon
dioxide with the non-hydraulic cement. Mixing carbon dioxide into
the cementitious mixture before the carbonation reaction can make
the end product less porous. Carbon dioxide can be mixed into the
cementitious mixture via injection. In some embodiments, carbon
dioxide can be injected for 1 second to 120 seconds. For example,
carbon dioxide can be injected for 120 seconds or less, 60 seconds
or less, 50 seconds or less, 45 seconds or less, 30 seconds or
less, 20 seconds or less, 15 seconds or less, or 10 seconds or
less. In some embodiments, the carbon dioxide can be injected for 1
second or more, 5 seconds or more, 10 seconds or more, 15 seconds
or more, 20 seconds or more, 25 seconds or more, 30 seconds or
more, 45 seconds or more, or 60 seconds or more.
[0043] In some embodiments, carbonating the cementitious mixture
can occur simultaneously with hydrating the cementitious mixture.
For example, water and carbon dioxide can be provided in the
cementitious mixture as a solution of carbon dioxide in water. In
some embodiments, water and carbon dioxide can be added separately
but simultaneously to the cementitious mixture.
[0044] In some embodiments, carbonating the cementitious mixture
occurs subsequent to hydrating the cementitious mixture. For
example, the cementitious mixture can be removed from the mold
before carbonating the cementitious mixture. In some embodiments,
carbonating the cementitious mixture can occur 5 minutes to 60
minutes after hydrating the cementitious mixture. In some
embodiments, carbonating the cementitious mixture can occur 10 to
55 minutes or 15 to 45 minutes after hydrating the cementitious
mixture.
[0045] Among other properties, the rate of strength development,
setting behavior, and ultimate compressive strength, can be
tailored by selecting an appropriate hydraulic cement. The desired
properties of the cementitious composition may also depend on the
particle size, crystal morphology, and treatment of the rapid
setting cement. Thus, the selection of the type of rapid setting
hydraulic cement used in the cementitious compositions can be based
on the balance of properties desired in the end application of the
cementitious compositions, including early demolding, product
transfer, or other secondary processing, while keeping a
sufficiently open network that would allow for good contact with
carbon dioxide in solution or as a gas for curing.
[0046] As described herein, the particle size and morphology of the
rapid setting cement can influence the development of green
strength and ultimate strengths of the cementitious composition.
Smaller particle size of the rapid setting cement may lead to more
rapid development in green strength. In some embodiments, when it
may be desirable to have an extremely rapid rate of strength
development, the average particle size of rapid setting cement can
be from 1 to 30 .mu.m. For example, the average particle size of
rapid setting cement can be 1 to 20 .mu.m or 1 to 10 .mu.m.
[0047] Similarly, an increase in the amount of rapid setting cement
in the cementitious composition can also lead to more rapid
development in green strength. For example, the hydraulic cement
can be included in the cementitious composition in an amount of
from 5 wt % to 80 wt % of the composition. One of ordinary skill in
the art would know how to select the amount of rapid setting cement
to be added to the cementitious mixture.
[0048] Rapid development and higher green strength can be an
advantage for a cementitious composition because it can withstand
higher stresses without excessive deformation. Further, higher
green strength can also increase the factor of safety relating to
handling and use of manufactured products. The rapid setting cement
may cause the cementitious composition to develop green strength in
90 minutes or less, 60 or less, 45 minutes or less, 30 minutes or
less, 15 minutes or less, 10 minutes or less, or 5 minutes or less.
For example, the rapid setting cement may cause the cementitious
composition to develop green strength in 30 minutes, 25 minutes, 20
minutes, 15 minutes, 10 minutes, or 5 minutes.
[0049] The green strength of the cementitious mixture can be
characterized by measuring the compressive strength or the flexural
strength of the cementitious composition. For example, green
strength can be determined using stress-strain relations using a
uniaxial compressive strength test as described by G. Husken, et
al., Cement and Concrete Research 2012, 42:501-510. The compressive
strength can be measured using the `standard test for compressive
strength of hydraulic cement mortars` as described by ASTM C109.
The flexural strength can be measured using the `standard test for
flexural strength of hydraulic cement mortars` as described by
ASTM. C348. In some embodiments, the rapid setting hydraulic cement
can have green strengths of 1,000 psi or greater, 1,500 psi or
greater, 2,000 psi or greater, 2,500 psi or greater, 3,000 psi or
greater, or 3,500 psi or greater, within about 90 minutes or less,
about 60 minutes or less, about 30 minutes or less, about 15
minutes or less after hydration. For example, the rapid setting
hydraulic cement can have green strengths of 1,000 psi or greater,
1,500 psi or greater, 2,000 psi or greater, 2,500 psi or greater,
3,000 psi or greater, or 3,500 psi or greater, within about 60
minutes or less after hydration.
[0050] In some embodiments, the cementitious composition has a
compressive strength of at least 1,000 psi in less than 15 minutes
after hydration. In some embodiments, the rapid setting hydraulic
cement provides a compressive strength of 1,000 psi or greater or
1,500 psi or greater in less than 15 minutes after hydration. In
some embodiments, the rapid setting hydraulic cement provides a
compressive strength of at least 2,000 psi within 60 minutes after
hydration. In some embodiments, the rapid setting hydraulic cement
provides a compressive strength of 2,000 psi or greater, 2,500 psi
or greater, 3,000 psi or greater, 3,500 psi or greater, or 4,000
psi or greater, within 60 minutes after hydration. In some
embodiments, the compressive strength of the completely cured
cementitious composition can be higher than that of a composition
comprising the hydraulic cement alone or the non-hydraulic cement
alone.
[0051] In some embodiments, the cementitious compositions are
suitable for use in extremely cold climates. For example, the
cementitious compositions disclosed can develop rapid green
strength at reduced temperatures from 0.degree. F. to 68.degree. F.
or from 10.degree. F. to 32.degree. F. In some embodiments, the
cementitious compositions are suitable for use at elevated
temperatures. For example, the cementitious compositions disclosed
can develop rapid green strength at elevated temperatures such as
150.degree. F. or greater, 175.degree. F. or greater, or
200.degree. F. or greater.
[0052] The methods of producing the cementitious compositions may
suitable for use in repair work, such as road repair, where high
green strengths may be desired. In some embodiments, the
cementitious compositions can be formed into shaped articles and
used in various applications, including building materials.
Examples of such building materials include roofing tiles, ceramic
tiles, architectural stone, thin bricks, bricks, hollow core
planks, pavers, panels, underlay (e.g., bathroom underlay),
banisters, lintels, pipe, posts, signs, guard rails, retaining
walls, park benches, tables, railroad ties, cross arms for
electrical poles, and other shaped articles.
[0053] The compositions and methods disclosed herein provide a
superior microstructure with stronger bonds and better mechanical
performance than Portland cement. In addition, the compositions and
methods disclosed herein provide reduced CO.sub.2 emittance and
lower energy requirements as compared to Portland cement.
[0054] The compositions and methods of the appended claims are not
limited in scope by the specific compositions and methods described
herein, which are intended as illustrations of a few aspects of the
claims and any compositions and methods that are functionally
equivalent are intended to fall within the scope of the claims.
Various modifications of the compositions and methods in addition
to those shown and described herein are intended to fall within the
scope of the appended claims. Further, while only certain
representative materials and method steps disclosed herein are
specifically described, other combinations of the materials and
method steps also are intended to fall within the scope of the
appended claims, even if not specifically recited.
[0055] Thus, a combination of steps, elements, components, or
constituents may be explicitly mentioned herein; however, other
combinations of steps, elements, components, and constituents are
included, even though not explicitly stated. The term "comprising"
and variations thereof as used herein is used synonymously with the
term "including" and variations thereof and are open, non-limiting
terms. Although the terms "comprising" and "including" have been
used herein to describe various embodiments, the terms "consisting
essentially of" and "consisting of" can be used in place of
"comprising" and "including" to provide for more specific
embodiments and are also disclosed. As used in this disclosure and
in the appended claims, the singular forms "a", "an", "the",
include plural referents unless the context clearly dictates
otherwise.
* * * * *