Abstract: A concrete structure formed of a mixture of concrete and a plurality of custom manufactured twisted steel micro-reinforcements (TSMRs). Each TSMR has a twist pitch of two or more twists per 25.4 mm applied along its longitudinal axis. The TSMRs are made from a common base stock and have the number of twists predetermined such that a concrete structure formed with at least 10 wt. % per unit volume less TSMRs than fibers in a conventional concrete structure exhibits the same or better performance than the conventional concrete structure in one or more of a stress, deflection, energy, or crack mouth opening (CMOD) properties as determined through defined standard tests. The performance requirement may be based on the actual test result and/or the consistency (coefficient of variation of the result).

Abstract: A method of making a fiber (100) that includes continuously receiving a round wire (10), forming the round wire into a fiber having to have a cross-sectional shape defining a truncated circle having an aspect ratio of between 1.53 and 1.88, and simultaneously pulling and twisting the fiber a threshold number of twists per inch while retaining the aspect ratio of the fiber.