Concrete reinforcing fibers

1. A reinforcing fiber comprising:

a body defining a longitudinal axis and having a cross section in the shape of a bilateral truncated circle, wherein the bilateral truncated circle has an aspect ratio between 1.53 and 1.93, wherein the aspect ratio is a ratio of width (w) to thickness (t) of the body,

wherein the body is twisted along its longitudinal axis;

wherein the body has a width (w) of between 0.01375 inches and 0.0159 inches.

2. The reinforcing fiber of claim 1 , wherein the body comprises a metal.

3. The reinforcing fiber of claim 1 , wherein the aspect ratio is 1.72 or 1.73.

4. The reinforcing fiber of claim 1 , wherein the aspect ratio is selected from the group consisting of the following ranges and values:

1.53-1.88; 1.53-1.83; 1.53-1.78; 1.53-1.73, 1.53-1.68, 1.53-1.63; 1.53-1.58; about 1.53; 1.58-1.93; 1.58-1.88; 1.58-1.83; 1.58-1.78; 1.58-1.73; 1.58-1.68; 1.58-1.63; 1.58-1.53; about 1.58; 1.63-1.93; 1.63-1.88; 1.63-1.83; 1.63-1.78; 1.63-1.73; 1.63-1.68; 1.63-1.58; 1.63-1.53; about 1.63; 1.68-1.93; 1.68-1.88; 1.68-1.83, 1.68-1.78; 1.68-1.73; 1.68-1.63; 1.68-1.58; 1.68-1.53; about 1.68; 1.73-1.93; 1.73-1.88; 1.73-1.83; 1.73-1.78; 1.73-1.68; 1.73-1.63: 1.73-1.58; 1.73-1.53; about 1.73); 1.78-1.93; 1.78-1.88; 1.78-1.83; 1.78-1.73; 1.78-1.68; 1.78-1.63; 1.78-1.58; 1.78-1.53; about 1.78; 1.83-1.93; 1.83-1.88; 1.83-1.78; 1.83-1.73; 1.83-1.68; 1.83-1.63; 1.83-1.58; 1.83-1.53; about 1.88; 1.88-1.93; 1.88-1.83; 1.88-1.78; 1.88-1.73; 1.88-1.68; 1.88-1.63; 1.88-1.58; 1.88-1.53; about 1.88; and about 1.93.

5. The reinforcing fiber of claim 1 , wherein the body has a between 3 and 4 twists along its longitudinal axis per every length (L) of between 20 mm and 40 mm.

6. The reinforcing fiber of claim 5 , wherein each twist comprises a rotation a first end of the body relative to a second end of the body of between 180° and 360°.

7. The reinforcing fiber of claim 4 , wherein the fiber is made by the method of passing a round wire through roller bearings under sufficient force to produce a fiber defining a bilateral truncated circle cross sectional shape.

8. The reinforcing fiber of claim 7 , wherein the method further comprising simultaneously pulling and twisting the fiber a threshold number of twists per inch while retaining the aspect ratio.

9. The reinforcing fiber of claim 7 , wherein the wire has a diameter of 0.51 mm.

10. A method of making a reinforcing fiber, the method comprising the steps of:

continuously receiving a round wire;

forming the round wire into a fiber having to have a cross-sectional shape defining a bitruncated circle having an aspect ratio of between 1.53 and 1.93, wherein the aspect ratio is a ratio of width (w) to thickness (t) of the fiber, wherein the body has a width (w) of between 0.01375 inches and 0.0159 inches; and

simultaneously pulling and twisting the fiber a threshold number of twists per inch while retaining the aspect ratio of the fiber.

11. The method of claim 10 , further comprising the step of twisting the fiber between 3 and 4 twists along its longitudinal axis per every length (L) of between 20 mm and 40 mm.

12. The method of claim 11 , further comprising the step of rotating a first end of a body of the fiber relative to a second end of the body of between 180° and 360° for each twist.

13. The method of claim 10 , further comprising the step of cutting the twisted fiber to a threshold length (L) free of holding the twisted fiber.

14. The method of claim 13 , further comprising the step of receiving and cutting the twisted fiber to a threshold length (L) while retaining the aspect ratio of the fiber.

15. The method of claim 13 , wherein the threshold length (L) comprises between 20 mm and 40 mm.

16. A composite structure comprising:

a matrix material; and

a fiber comprising a body defining a longitudinal axis and having a cross section in the shape of a bitruncated circle, wherein the truncated circle has an aspect ratio between 1.53 and 1.93, wherein the aspect ratio is a ratio of width (w) to thickness (t) of the body, wherein the body has a width (w) of between 0.01375 inches and 0.0159 inches;

wherein the body is twisted along its longitudinal axis.

17. The composite structure of claim 16 , wherein the body ( 110 ) comprises metal, preferably steel.

18. The composite structure of claim 16 , wherein the aspect ratio is 1.72 or 1.73.

19. The composite structure of claim 16 , wherein the aspect ratio is selected from the group consisting of the following ranges and values:

1.53-1.88; 1.53-1.83; 1.53-1.78; 1.53-1.73, 1.53-1.68, 1.53-1.63; 1.53-1.58; about 1.53; 1.58-1.93; 1.58-1.88; 1.58-1.83; 1.58-1.78; 1.58-1.73; 1.58-1.68; 1.58-1.63; 1.58-1.53; about 1.58; 1.63-1.93; 1.63-1.88; 1.63-1.83; 1.63-1.78; 1.63-1.73; 1.63-1.68; 1.63-1.58; 1.63-1.53; about 1.63; 1.68-1.93; 1.68-1.88; 1.68-1.83, 1.68-1.78; 1.68-1.73; 1.68-1.63; 1.68-1.58; 1.68-1.53; about 1.68; 1.73-1.93; 1.73-1.88; 1.73-1.83; 1.73-1.78; 1.73-1.68; 1.73-1.63: 1.73-1.58; 1.73-1.53; about 1.73); 1.78-1.93; 1.78-1.88; 1.78-1.83; 1.78-1.73; 1.78-1.68; 1.78-1.63; 1.78-1.58; 1.78-1.53; about 1.78; 1.83-1.93; 1.83-1.88; 1.83-1.78; 1.83-1.73; 1.83-1.68; 1.83-1.63; 1.83-1.58; 1.83-1.53; about 1.88; 1.88-1.93; 1.88-1.83; 1.88-1.78; 1.88-1.73; 1.88-1.68; 1.88-1.63; 1.88-1.58; 1.88-1.53; about 1.88; and about 1.93.

20. The composite structure of claim 16 , wherein the body has between 3 and 4 twists along its longitudinal axis per every length (L) of between 20 mm and 40 mm.

21. The composite structure of claim 20 , wherein each twist comprises a rotation a first end of the body relative to a second end of the body of between 180° and 360°.

22. The composite structure of claim 16 , wherein the matrix material comprises cement or a polymeric based material.