Self-stressing engineered composite materials, methods of self-stressing engineered composite materials, and self-stressing reinforcement for same

Patent metadata

Field	Value
Publication number	US-11027519-B2
Application number	US-201615569655-A
Country	US
Kind code	B2
Filing date	Apr 29, 2016
Priority date	Apr 29, 2015
Publication date	Jun 8, 2021
Grant date	Jun 8, 2021

Abstract

Self-stressing engineered composites that include a matrix containing self-stressing reinforcement that is activated by an activator that causes, in situ, the self-stressing reinforcement to transfer at least some of its pre-stress into portions of the matrix adjacent the self-stressing reinforcement. In some embodiments, the activator can be of a self-activating, an internal activating, and/or an external activating type. In some embodiments, the self-stressing reinforcement includes an active component that holds and transfers pre-stress to a matrix and a releasing component that causes the active component to transfer its pre-stress to the matrix. In some embodiments, the self-stressing reinforcement is initially unstressed and becomes stressed upon activation. Various engineered composites, self-stressing reinforcement, and applications of self-stressing engineered composites are disclosed.

First claim

What is claimed is:

1. Self-stressing reinforcement for an engineered composite comprising a matrix having a cure time for achieving a cured state from an uncured state, the self-stressing reinforcement comprising:
a body designed and configured so that, when said body is present in the matrix, stress transfers between portions of the body and the matrix in the cured state, the body composed of at least one material chemically responsive to an activator present within the matrix so as to cause a change in the body that results in tensile stress in the body inducing compressive stress into the matrix so as to cause the matrix to be pre-stressed in the cured state, wherein the activator is selected from a group consisting of:
a self-activator present in the matrix but not as an additive; and
an internal activator internal to the matrix and added to the matrix as an additive;

wherein the body comprises a releasing component and an active component, wherein, when the self-stressing reinforcement is present in the matrix and exposed to the activator:
the releasing component is chemically activated by the activator to release pre-stress in the active component so as to transfer a portion of the pre-stress into the adjacent portions of the matrix to create the compressive stress in the adjacent portions of the matrix; and
the active component comprises a core and the releasing component comprises a sleeve surrounding the core and holding the core in tension prior to activation, wherein the sleeve comprises the at least one material that responds chemically to the activator.

2. Self-stressing reinforcement according to claim 1 , wherein at least one of the at least one material and the activator are designed and configured to control the change as a function of the cure time.

3. A pre-stressed engineered composite comprising each of the matrix and the self-stressing reinforcement of claim 1 .

4. A method of making a pre-stressed engineered composite comprising adding the self-stressing reinforcement of claim 1 to the matrix.

5. The method according to claim 4 , further comprising adding the activator to the matrix.

6. A method of rejuvenating a structural component, the method comprising:
applying a patch to the structural component, the patch comprising a matrix and self-stressing reinforcement; and
causing the self-stressing reinforcement to chemically activate so as to impart tensile strain within the patch so as to cause the patch to impart at least part of the tensile strain into the structural component as compressive strain.

7. The method according to claim 6 , wherein the matrix of the patch comprises a polymer.

8. The method according to claim 6 , wherein the activating of the self-stressing reinforcement occurs in response to curing of the matrix of the patch.

9. The method according to claim 6 , wherein the activating of the self-stressing reinforcement includes adding an internal activator to the matrix of the patch.

10. The method according to claim 6 , wherein the activating of the self-stressing reinforcement includes applying an external activator to the patch.

11. An engineered composite, comprising:
a matrix;
self-stressing reinforcement contained in the matrix, wherein the self-stressing reinforcement is designed, configured, and comprised of a material composed to respond chemically to an activator so as to cause the self-stressing reinforcement to undergo a change in internal stress within the self-stressing reinforcement and thereby impart compressive stress into adjacent portions of the matrix in physical contact with the self-stressing reinforcement; and
the activator, wherein the activator is selected in conjunction with the material of the self-stressing reinforcement to activate the self-stressing reinforcement and is selected from the group consisting of:
a self-activator present within the matrix but not as an additive; and
an internal activator within the matrix and added to the matrix as an additive;

wherein:
the self-stressing reinforcement comprises, within the matrix, a releasing component and an active component;
the releasing component is chemically activated by the activator to release pre-stress in the active component so as to transfer a portion of the pre-stress into the adjacent portions of the matrix to create the compressive stress in the adjacent portions of the matrix; and
the active component comprises a core and the releasing component comprises a sleeve surrounding the core and holding the core in tension prior to activation, wherein the sleeve comprises the at least one material that responds chemically to the activator.

12. The engineered composite according to claim 11 , wherein the matrix comprises a cementitious material.

13. The engineered composite according to claim 11 , wherein the matrix comprises a polymer.

14. The engineered composite according to claim 11 , wherein the material comprises a poly-base polymer responsive to the activator.

15. The engineered composite according to claim 14 , wherein the poly-base polymer comprises a pH-responsive material selected from the group consisting of chitosan-derived biopolymers and collagens.

16. The engineered composite according to claim 11 , wherein the self-stressing reinforcement comprises a plurality of fibers distributed randomly within the matrix.

17. An engineered composite, comprising:
a matrix;
self-stressing reinforcement contained in the matrix, wherein the self-stressing reinforcement is designed, configured, and comprised of a material composed to respond chemically to an activator so as to cause the self-stressing reinforcement to undergo a change in internal stress within the self-stressing reinforcement and thereby impart compressive stress into adjacent portions of the matrix in physical contact with the self-stressing reinforcement; and
the activator, wherein the activator is selected in conjunction with the material of the self-stressing reinforcement to activate the self-stressing reinforcement and is selected from the group consisting of:
a self-activator present within the matrix but not as an additive; and
an internal activator within the matrix and added to the matrix as an additive;

wherein:
the material comprises a poly-base polymer responsive to the activator; and
the poly-base polymer comprises a pH-responsive material selected from the group consisting of chitosan-derived biopolymers and collagens.

18. The engineered composite according to claim 17 , wherein the self-stressing reinforcement comprises, within the matrix, a releasing component and an active component, wherein the releasing component is chemically activated by the activator to release pre-stress in the active component so as to transfer a portion of the pre-stress into the adjacent portions of the matrix to create the compressive stress in the adjacent portions of the matrix.

19. The engineered composite according to claim 18 , wherein the active component comprises a core and the releasing component comprises a sleeve surrounding the core and holding the core in tension prior to activation, wherein the sleeve comprises the material that responds chemically to the activator.

20. An engineered composite, comprising:
a matrix;
self-stressing reinforcement contained in the matrix, wherein the self-stressing reinforcement is designed, configured, and comprised of a material composed to respond chemically to an activator so as to cause the self-stressing reinforcement to undergo a change in internal stre

Assignees

• The Univ Of Vermont And State Agricultural College

Inventors

• Lee Patrick Chang Dong
• Huston Dryver R
• Tan Ting

Classifications

• C04B2111/00612

  as one or more layers of a layered structure · CPC title

• B32B2556/00

  Patches, e.g. medical patches, repair patches · CPC title

• B32B13/14

  next to a fibrous or filamentary layer · CPC title

• B32B13/02

  with fibres or particles {being present as additives in the layer} · CPC title

• B32B2419/00

  Buildings or parts thereof · CPC title