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US4407769A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of manufacturing cement products having superior mechanical strength

Assignee: Inax Corp
•
Filing: 1980-04-02
•
Granted: 1983-10-04
•
Expires: 2000-04-02
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Abstract

Abstract This invention is based on the discovery by the inventors that, if a preliminary hydration hardening process and a full-scale hydration hardening process are provided after the molding process, and a process for burning a hardened body of cement at a high temperature is provided between the preliminary and full-scale hardening processes, it is possible to obtain a molded product of cement having a higher mechanical strength than any such product according to any known method including no such burning process. According to this invention, there is provided a method of manufacturing a product of cement having high mechanical strength, which method comprises the steps in sequence of adding water, and if required, glass fibers or other reinforcing material, into a mixture of cement and an aggregate, and kneading the whole completely; molding the kneaded mixture into a desired shape; hardening the molded body preliminarily by hydration; burning the preliminarily hardened body at a high temperature; and hardening the burned body on a full scale by hydration.

Inventors

  • 👤 Shozo Harada
  • 👤 Kazuo Ito
  • 👤 Takayuki Shirai
  • 👤 Tetsuya Koide

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-26 22:46
CPC Classifications
C; C04; C04B; C04B40/00; C04B40/02; C04B41/00; C04B41/45; C04B41/50

Claims Analysis

Total Claims: 7
Claim 1
Independent Claim 94 words
A method of manufacturing a product of cement, which comprises the steps in sequence of: adding water into a mixture of cement and an aggregate, and kneading the mixture; molding the resulting kneaded mixture into a desired shape; preliminarily hardening the resulting molded body by hydration; burning the entire body thus preliminarily hardened at a temperature of about 650° to about 950° C. to initially decrease the mechanical strength thereof; hardening the burned body by subjecting said body to further hydration by application of water thereto so as to enhance the mechanical strength thereof.
Claim 2
Independent Claim 94 words
A method of manufacturing a product of cement, which comprises the steps in sequence of: adding water into a mixture of cement and an aggregate, and kneading the mixture; molding the resulting kneaded mixture into a desired shape; preliminarily hardening the resulting molded body by hydration; burning the entire body thus preliminarily hardened at a temperature of about 650° to about 950° C. to initially decrease the mechanical strength thereof; hardening the burned body by subjecting said body to further hydration by application of water thereto so as to enhance the mechanical strength thereof.
Claim 3
Dependent Claim 17 words
A method as set forth in claim 1, wherein said cement mixture also contains a reinforcing material.
Claim 4
Dependent Claim 77 words
A method as set forth in claim 1 or or 2, wherein said burning is performed by burning a smoking agent in a reducing atmosphere to form a lustrous coating of film on the surface of the molded body, while at the same time burning the molded body, said smoking agent containing a hydrocarbon, whereby said hydrocarbon is thermally decomposed to form fine particles of carbon which are deposited on the surface of said preliminarily hardened body.
Claim 5
Dependent Claim 30 words
A method as set forth in claim 1 or 2, wherein a glaze having a high melting point is applied to the preliminarily hardened body prior to the burning step.
Claim 6
Dependent Claim 29 words
A method as set forth in claim 4, wherein said glaze is selected from the group consisting of, feldspar, clay, glass powder, zinc oxide, zirconium oxide or mixtures thereof.
Claim 7
Dependent Claim 27 words
A method according to claim 2 in which the reinforcing material is selected from the group consisting of glass fibers, ceramic fibers, metal fibers and metal wire.

References Cited (Backward Citations)

US2579050A Cited
US2562477A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1986-10-03 1987-04-04 1987-10-04 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1990-10-03 1991-04-04 1991-10-04 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1994-10-03 1995-04-04 1995-10-04 $7700.00 Window Closed / Lapsed

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