Patent US4002483A successfully refreshed from Google Patents.
US4002483A
Expired / Lapsed
US
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Expansive cement
Assignee: Lafarge North America Inc
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Filing: 1975-06-12
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Granted: 1977-01-11
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Expires: 1995-06-12
Abstract
Abstract An improved expansive cement composition is provided which has the increased capability of being able to " grab" steel reinforcement members therewithin as the material is curing and expanding to result in effective stressing of the reinforcement members. This cement is made of particulate argillaceous and calcareous materials, and contains from about 1 to about 70% by weight of free CaO and from about 2 to about 7% by weight of MgO uniformly distributed therein, with the remaining portion being primarily tricalcium silicate and containing substantially no dicalcium silicate. The improved expansive composition can be manufactured by subjecting a conventional Portland cement raw mix, which has been "overlimed" and which contains the added quantity of MgO, to hard burning conditions within a Portland cement kiln such that the silicate materials are reacted with lime to form tricalcium silicate but yet leave from about 1 to about 70% by weight of the free CaO, and from about 2 to about 7% by weight of the MgO in the clinker, and thereafter comminuting the clinker. The composition can be used directly as an expansive cement, or can be mixed with other cements such as Portland cements to impart expansive qualities thereto.
Inventors
- 👤 Kenneth E. Daugherty
- 👤 John P. Luker
- 👤 Joseph H. Allen
- 👤 Waldemar A. Klemm
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 12:09
CPC Classifications
C; C04; C04B; C04B7/00; C04B7/02
Claims Analysis
Total Claims: 41
Claim 1
Independent Claim
56 words
An expansive cement composition made of argillaceous and calcareous materials and containing from about 1 to about 70% by weight thereof of free CaO and from about 2 to about 7% by weight thereof of MgO uniformly distributed therein, with the remaining portion of said materials being primarily tricalcium silicate and containing substantially no dicalcium silicate.
Claim 2
Dependent Claim
56 words
An expansive cement composition made of argillaceous and calcareous materials and containing from about 1 to about 70% by weight thereof of free CaO and from about 2 to about 7% by weight thereof of MgO uniformly distributed therein, with the remaining portion of said materials being primarily tricalcium silicate and containing substantially no dicalcium silicate.
Claim 3
Dependent Claim
38 words
The expansive cement composition of claim 1 wherein said MgO exists in the form of a solid solution and of crystal particles, and wherein at least 75% of said crystal particles are no larger than about 10 microns.
Claim 4
Dependent Claim
29 words
The expansive cement composition of claim 1 having a particle size no larger than about 80 mesh (Tyler) and a fineness no greater than about 4700 cm 2 /gm.
Claim 5
Dependent Claim
20 words
The expansive cement composition of claim 3 having from about 5 to about 30% by weight thereof of free CaO.
Claim 6
Dependent Claim
26 words
The expansive cement composition of claim 3 having a particle size that passes 100 mesh (Tyler) and a fineness no greater than 3700 cm 2 /gm.
Claim 7
Dependent Claim
18 words
The expansive cement composition of claim 5 having a fineness between about 2000 and 3700 cm 2 /gm.
Claim 8
Dependent Claim
86 words
An expansive cement composition made by burning mixtures of magnesia supplying materials and argillaceous and calcareous reactant materials containing an excess of CaO relative to silica under conditions to thereby convert substantially all of the silica into tricalcium silicate and uniformly distribute said magnesia in said composition, said composition containing from about 1 to about 70% by weight of free CaO and from about 2 to about 7% by weight of MgO with the remaining portion being primarily tricalcium silicate and containing substantially no dicalcium silicate.
Claim 9
Dependent Claim
86 words
An expansive cement composition made by burning mixtures of magnesia supplying materials and argillaceous and calcareous reactant materials containing an excess of CaO relative to silica under conditions to thereby convert substantially all of the silica into tricalcium silicate and uniformly distribute said magnesia in said composition, said composition containing from about 1 to about 70% by weight of free CaO and from about 2 to about 7% by weight of MgO with the remaining portion being primarily tricalcium silicate and containing substantially no dicalcium silicate.
Claim 10
Dependent Claim
35 words
The expansive cement composition of claim 7 further comprising a liquid phase which forms during the burning thereof which is in the range of from about 15 to about 35% by weight of said composition.
Claim 11
Dependent Claim
47 words
The expansive cement composition of claim 8 wherein said magnesia is present in said composition in solid solution in said liquid phase and the silicate phase thereof and in crystals wherein at least about 75% of the crystals have a size no larger than about 10 microns.
Claim 12
Dependent Claim
29 words
The expansive cement composition of claim 7 having a particle size no larger than about 80 mesh (Tyler) and a fineness no greater than about 4700 cm 2 gm.
Claim 13
Dependent Claim
19 words
The expansive cement composition of claim 10 containing from about 5 to about 30% by weight of free CaO.
Claim 14
Dependent Claim
21 words
The expansive cement composition of claim 10 containing from about 5 to less than about 40% by weight of free CaO.
Claim 15
Dependent Claim
26 words
The expansive cement composition of claim 10 having a particle size that passes 100 mesh (Tyler) and a fineness no greater than 3700 cm 2 /gm.
Claim 16
Dependent Claim
18 words
The expansive cement composition of claim 13 having a fineness of between 2000 and 3700 cm 2 /gm.
Claim 17
Dependent Claim
105 words
An expansive cement composition made by burning mixtures of magnesia supplying materials and argillaceous and calcareous reactive materials containing an excess of CaO relative to silica and burned under conditions to thereby convert substantially all of the silica into tricalcium silicate, and uniformly distribute MgO therewithin, said composition containing from about 1 to about 70% by weight thereof of free CaO and a minor but effective amount of MgO which is sufficient to increase the ability of the resulting composition when hydrating to grab steel reinforcement members therewithin, and the remaining portion of said composition being primarily tricalcium silicate and containing substantially no dicalcium silicate.
Claim 18
Dependent Claim
105 words
An expansive cement composition made by burning mixtures of magnesia supplying materials and argillaceous and calcareous reactive materials containing an excess of CaO relative to silica and burned under conditions to thereby convert substantially all of the silica into tricalcium silicate, and uniformly distribute MgO therewithin, said composition containing from about 1 to about 70% by weight thereof of free CaO and a minor but effective amount of MgO which is sufficient to increase the ability of the resulting composition when hydrating to grab steel reinforcement members therewithin, and the remaining portion of said composition being primarily tricalcium silicate and containing substantially no dicalcium silicate.
Claim 19
Dependent Claim
64 words
An expansive cement comprising a mixture of: a. a hydratable cement; and b. an expansive composition made from argillaceous and calcareous materials and containing from about 1 to about 70% by weight of free CaO, and from about 2 to about 7% by weight thereof of MgO uniformly distributed therein, with the remaining portion being primarily tricalcium silicate and containing substantially no dicalcium silicate.
Claim 20
Dependent Claim
64 words
An expansive cement comprising a mixture of: a. a hydratable cement; and b. an expansive composition made from argillaceous and calcareous materials and containing from about 1 to about 70% by weight of free CaO, and from about 2 to about 7% by weight thereof of MgO uniformly distributed therein, with the remaining portion being primarily tricalcium silicate and containing substantially no dicalcium silicate.
Claim 21
Dependent Claim
13 words
The expansive cement of claim 16 wherein said hydratable cement is Portland cement.
Claim 22
Dependent Claim
25 words
The expansive cement of claim 17 wherein said mixture is made by intergrinding a Portland cement clinker and a clinker of said expansive cement composition.
Claim 23
Dependent Claim
23 words
The expansive cement of claim 16 wherein said expansive composition contains from about 5 to less than about 40% by weight of CaO.
Claim 24
Dependent Claim
21 words
The expansive cement of claim 19 wherein said expansive composition contains from about 5 to about 30% by weight of CaO.
Claim 25
Dependent Claim
32 words
The expansive cement of claim 16 wherein said expansive composition has a particle size no larger than about 80 mesh (Tyler) and a fineness no greater than about 4700 cm 2 /gm.
Claim 26
Dependent Claim
29 words
The expansive cement of claim 21 wherein said expansive composition has a particle size that passes 100 mesh (Tyler) and a fineness no greater than 3700 cm 2 /gm.
Claim 27
Dependent Claim
21 words
The expansive cement of claim 22 wherein said expansive composition has a fineness of between 2000 and 3700 cm 2 /gm.
Claim 28
Dependent Claim
33 words
The expansive cement of claim 16 containing from about 1 to about 99% by weight thereof of Portland cement and from about 99 to about 1% by weight thereof of said expansive composition.
Claim 29
Dependent Claim
25 words
The expansive cement of claim 24 wherein said expansive composition contains from about 5 to less than about 40% by weight of said free CaO.
Claim 30
Dependent Claim
23 words
The expansive cement of claim 25 wherein said expansive composition contains from about 5 to about 30% by weight of said free CaO.
Claim 31
Dependent Claim
14 words
The expansive cement of claim 16 wherein said hydratable cement is a pozzolanic cement.
Claim 32
Independent Claim
189 words
A method of producing an expansive cement composition comprising: a. introducing magnesia supplying materials and argillaceous and calcareous reactant materials to the feed end of a kiln, said calcareous reactant materials containing sufficient CaO forming materials to completely react with the argillaceous materials in the kiln and to provide an excess of unreacted CaO in the burned clinker in the range of from about 1 to about 70% by weight thereof, said magnesia supplying materials supplying said MgO in an amount in the range of from about 2 to about 7% by weight of said composition; b. burning said materials in a burning zone in said kiln at a temperature in the range of from about 2500° F to about 2900° F and for a sufficient time to convert substantially all of the silicate in said argillaceous materials to tricalcium silicate and yield substantially no dicalcium silicate, but yield from about 1 to about 70 weight percent of free CaO in the resulting burned clinker, and to uniformly disperse said MgO in the resulting burned clinker; and c. grinding said clinker to produce a powdered hydraulic expansive cement composition.
Claim 33
Independent Claim
189 words
A method of producing an expansive cement composition comprising: a. introducing magnesia supplying materials and argillaceous and calcareous reactant materials to the feed end of a kiln, said calcareous reactant materials containing sufficient CaO forming materials to completely react with the argillaceous materials in the kiln and to provide an excess of unreacted CaO in the burned clinker in the range of from about 1 to about 70% by weight thereof, said magnesia supplying materials supplying said MgO in an amount in the range of from about 2 to about 7% by weight of said composition; b. burning said materials in a burning zone in said kiln at a temperature in the range of from about 2500° F to about 2900° F and for a sufficient time to convert substantially all of the silicate in said argillaceous materials to tricalcium silicate and yield substantially no dicalcium silicate, but yield from about 1 to about 70 weight percent of free CaO in the resulting burned clinker, and to uniformly disperse said MgO in the resulting burned clinker; and c. grinding said clinker to produce a powdered hydraulic expansive cement composition.
Claim 34
Dependent Claim
54 words
The method of claim 28 wherein said magnesia supplying materials and said argillaceous and calcareous reactant materials fed to said kiln have a particle size such that no less than about 97% thereof passes through a 50 mesh (Tyler) screen, and no less than about 80% thereof passes through a 200 mesh (Tyler) screen.
Claim 35
Dependent Claim
36 words
The method of claim 28 wherein a liquid phase forms during said burning of said materials and is in the range of from about 15 to about 35 percent by weight of said resulting burned clinker.
Claim 36
Dependent Claim
49 words
The method of claim 30 wherein said burning results in said MgO being uniformly distributed throughout said composition in the form of a solid solution and in the form of crystals and wherein at least 75% of said crystals have a size of no more than about 10 microns.
Claim 37
Dependent Claim
31 words
The method of claim 31 wherein said grinding yields particles having a size no larger than about 80 mesh (Tyler) and a fineness no greater than about 4700 cm 2 /gm.
Claim 38
Dependent Claim
28 words
The method of claim 32 wherein said free CaO is present in said composition in the range from about 5 to less than about 40% by weight thereof.
Claim 39
Dependent Claim
29 words
The method of claim 33 wherein said CaO is present in said composition in an amount in the range of from about 5 to about 30% by weight thereof.
Claim 40
Dependent Claim
29 words
The method of claim 33 wherein said clinker is ground to a particle size that passes 100 mesh (Tyler) and a fineness no greater than 3700 cm 2 /gm.
Claim 41
Dependent Claim
21 words
The method of claim 35 wherein said clinker is ground to a fineness of between 2000 and 3700 cm 2 /gm.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-01-11 | 1980-07-12 | 1981-01-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-01-11 | 1984-07-12 | 1985-01-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-01-11 | 1988-07-12 | 1989-01-11 | $7700.00 | Window Closed / Lapsed |