Cementitious materials

• US 5,575,841 A
• Filed: 12/29/1993
• Issued: 11/19/1996
• Est. Priority Date: 06/19/1990
• Status: Expired due to Term

• Current Assignee: Carolyn M. Dry
• Original Assignee: Carolyn M. Dry
• Inventors: Dry, Carolyn M.
• Primary Examiner(s): Bell, Mark L.
• Assistant Examiner(s): MARCHESCHI, MICHAEL A
• Application Number:
  US08/174,751
• Time in Patent Office: 1,056 Days
• Field of Search: 106/677, 106/711, 106/727, 106/802, 106/819, 106/823, 428/320.2, 428/321.5, 428/321.1, 428/364, 428/375
• US Class Current: 106/711
• CPC Class Codes: A61L 27/48 with macromolecular fillers
• CPC Class Codes: B28B 17/00 Details of, or accessories for, apparatus for shaping the material; Auxiliary measures taken in connection with such shaping moulds B28B7/00; after-treatment B28B11/00; feeding or discharging B28B13/00; arrangements for embedding elements in the material B28B23/00
• CPC Class Codes: C04B 20/0048 Fibrous materials
• CPC Class Codes: C04B 20/0056 Hollow or porous fibres
• CPC Class Codes: C04B 22/006 released by a chemical reaction, e.g. polymer condensation
• CPC Class Codes: C04B 38/0003 containing continuous channels, e.g. of the "dead-end" type or obtained by pushing bars in the green ceramic product B28B takes precedence
• CPC Class Codes: C04B 40/0028 Aspects relating to the mixing step of the mortar preparation
• CPC Class Codes: C04B 40/0092 Temporary binders, mortars or concrete, i.e. materials intended to be destroyed or removed after hardening, e.g. by acid dissolution
• CPC Class Codes: C04B 40/0263 Hardening promoted by a rise in temperature C04B40/024 takes precedence
• CPC Class Codes: C04B 40/06 Inhibiting the setting, e.g. mortars of the deferred action type containing water in breakable containers ; Inhibiting the action of active ingredients
• CPC Class Codes: C04B 40/0633 Chemical separation of ingredients, e.g. slowly soluble activator
• CPC Class Codes: C04B 40/0675 Mortars activated by rain, percolating or sucked-up water; Self-healing mortars or concrete
• CPC Class Codes: C08J 3/241 Preventing premature crosslinking by physical separation of components, e.g. encapsulation
• CPC Class Codes: C08K 7/00 Use of ingredients characterised by shape
• CPC Class Codes: Y10T 428/249994 Composite having a component wherein a constituent is liquid or is contained within preformed walls [e.g., impregnant-filled, previously void containing component, etc.]
• CPC Class Codes: Y10T 428/249995 Constituent is in liquid form
• CPC Class Codes: Y10T 428/249996 Ink in pores
• CPC Class Codes: Y10T 428/2913 Rod, strand, filament or fiber

Abstract

A cementitious material, such as concrete, contains carriers having within them an agent for improving the physical properties of the cementitious material. The agent is released from the carriers into the cementitious material at a desired time after setting by the action of an external stimulus.

Claims

1. A shaped article comprising:

a cured matrix material having a plurality of hollow fibers dispersed therein, said hollow fibers having a releasable modifying agent contained therein, means for maintaining the modifying agent within the fibers until released and means for permitting release of the modifying agent from the hollow fibers into the matrix material in response to at least one external stimulus.

2. A shaped article as defined in claim 1, wherein said matrix material is a settable construction material.

3. A shaped article as defined in claim 1, wherein said matrix material is a cementitious material.

4. A shaped article as defined in claim 1, wherein said hollow fibers comprises of polypropylene, polyamide, glass ceramic or cellulose hollow fibers.

5. A shaped article as defined in claim 1, wherein said hollow fibers are elastomeric.

6. A shaped article as defined in claim 1, wherein said hollow fibers are porous polypropyrlene.

7. A shaped article as defined in claim 1, wherein said modifying agent is a liquid.

8. A shaped article as defined in claim 1, wherein said modifying agent comprises impregnators, sealants, adhesives, water barriers, anti-corrosion agents, anti-freeze agents or fiber protection modifying agents.

9. A shaped article as defined in claim 1, wherein said means for maintaining the modifying agent within the fibers comprises a coating material disposed on said fibers.

10. A shaped article as defined in claim 1, wherein said modifying agent filled hollow fibers comprise less than about 10 volume percent of said matrix material.

11. A shaped article as define in claim 1, wherein said matrix material is an inorganic matrix material.

19. A shaped article as defined in claim 1, wherein said hollow fibers are glass.

12. A method for making a shaped article comprising the steps of preparing a curable matrix material in an uncured state;

adding to the uncured matrix material at least one hollow fiber, said hollow fiber having a releasable modifying agent contained therein, said fiber further having means for maintaining the modifying agent within the fiber until released and means for permitting release of the modifying agent from the hollow fiber into the matrix material after cure in response to at least one external stimulus; and

shaping and curing the matrix material and fiber to provide a shaped article.

13. An additive for improving final, cured properties of a curable matrix composition, maid additive comprising:

a hollow faber having a releasable modifying agent contained therein, means for maintaining the modifying agent within the fibers until released and means for permitting release of modifying agent from the hollow fibers into a matrix material in which the hollow fiber has been added in response to at least one external stimulus.

14. An additive as defined in claim 13, wherein the hollow fiber comprises polypropylene, polyamide, glass, ceramic or cellulose fibers.

15. An additive as defined in claim 13, wherein said hollow fiber is a porous material.

16. An additive as defined in claim 13, wherein said modifying agent is a liquid.

17. An additive as defined in claim 16, wherein said means for maintaining the modifying agent within the fiber until released comprises a coating material on the filled fiber.

18. An additive as defined in claim 13, wherein said modifying agent comprises impregnators, sealants, adhesives, water barriers, anti-corrosion agents, anti-freeze agents or fiber protection modifying agents.