Heavy-duty macro-synthetic fibers represent the next generation of synthetic technology, capable of a much more higher replacement level of conventional steel reinforcement. The FORTA-FERRO® macro fiber maximizes each of the critical fiber characteristics that contribute to long term durability and crack-control performance. Using advanced co-polymer chemistry and a blend of fiber shapes, along with twisted bundles and special gray color to assure uniform mixing and excellent surface finish, this unique best-of-its-kind macrosynthetic may be used at a much higher dosage (3.0,5.0,7.5 lbs./cu.yd. or more). FORTA-FERRO® has the highest slab curling reduction and best post-crack performance values of any synthetic fiber in its class.