Sources: Helix Steel, Ann Arbor, Mich.; CP staff
A proprietary test described in ASTM International’s Journal of Testing and Evaluation provides for direct comparison of steel fiber and conventional rebar concrete specimen tensile properties, according to Helix Steel, developer of Twisted Steel Micro Reinforcement.
Product developers characterize Helix 5-25 Micro-Rebar Concrete Reinforcement System as the only code approved material of its kind engineers can confidently specify as a replacement for primary structural reinforcing. Micro-Rebar are .5-mm diameter, 25-mm (1-in.) long fibers of twisted, high tensile (246 ksi), zinc-coated steel wire, dosed at 9 lb. to 70 lb. per cubic yard of concrete. Each pound of product has about 11,500 fibers.