Patent ID: 7462392

Claim:
Fibers for reinforcing a concrete or other matrix material, comprising: fiber bodies having two opposed ends defining therebetween an intermediate elongated fiber body portion which is substantially non-fractured and non-fibrillatable when mixed into a matrix material such as concrete, shotcrete, mortar, grout, or synthetic polymer, the fiber body portion having a length of 5 mm - 100 mm; the body portion defining longitudinal major axis Z and comprising a transverse cross-sectional profile having two tapering dimensions for pull out-resistance from the concrete or other matrix material, the first tapering dimension occurring in a first transverse minor axis X that is perpendicular to axis Z, the second tapering dimension occurring in a second transverse minor axis Y that is perpendicular to both axes X and Z; the first and second tapering dimensions having inverted tapering behaviors wherein, alone axis Z, the first tapering dimension along axis X increases as the second tapering dimension along axis Y decreases, and the first tapering dimension along axis X decreases as the second tapering dimension along axis Y increases; the transverse cross-sectional area remaining substantially uniform along axis Z having said inverted tapering dimensional behaviors; and said fibers having an aspect ratio in terms of length to eguivalent diameter of not less than 10 and not greater than 500, a modulus of elasticity not less than 5 Gigapascals and not greater than 250 Gigapascals, a tensile strength not less than 400 Megapascals and not greater than 2,500 Megapascals, and a load carrying capacity of not less than 50 Newtons per fiber and not greater than 5,000 Newtons per fiber.