ASTM D7957/D7957M-17

This specification covers glass fiber reinforced polymer (GFRP) bars, provided in cut lengths and bent shapes and having an external surface enhancement for concrete reinforcement. It specifies the property limits and test methods for qualification, quality control and certification of GFRP bars, the geometric and mechanical property requirements, and minimum inside bend diameter of bent bars. Physical properties include fiber mass content, glass transition temperature, degree of cure, and bar sizes), whereas mechanical properties include ultimate tensile force, tensile modulus of elasticity, ultimate tensile strain, transverse shear strength, and bond strength.This specification also covers the manufacturing process for constituent materials, namely, reinforcing fibers and matrix resins; durability properties (moisture absorption, resistance to alkaline environment); sampling (product qualification, quality control and certification); product certification; and markings and traceability.