A composite material used to form a concrete structure that includes a concrete matrix formed of a mixture of aggregates and a paste and a mixture of twisted steel micro-reinforcements (TSMRs) dispersed within the concrete matrix. The TSMRs have a variable twist pitch; wherein the twist pitch of a portion of the TSMRs is in the range of 6 to 20 twists per 25.4 mm (1 inch) applied along its longitudinal axis. The TSMRs are made from a common base stock and have the number of twists predetermined, such that the concrete structure exhibits at least 10% greater performance in one or more of a stress, deflection, energy, or crack mouth opening (CMOD) properties as determined through one or more defined standard tests than a similar concrete structure formed with the same amount by weight of steel fibers having one or two bends.