ASTM D7957/D7957M-2017 混凝土鋼筋用實(shí)心圓形玻璃纖維增強聚合物筋的規格 Standard Specification for Solid Round Glass Fiber Reinforced Polymer Bars for Concrete Reinforcement

1.1 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. Bars covered by this specification shall meet the requirements for geometric, material, mechanical, and physical properties described herein. 1.2 Bars produced according to this standard are qualified using the test methods and must meet the requirements given by Table 1. Quality control and certification of production lots of bars are completed using the test methods and must meet the requirements given in Table 2. TABLE 1 Property Limits and Test Methods for QualificationA Property Limit Test Method Mean Glass Transition Temperature Midpoint temperature ≥100 °C [212 °F] ASTM E1356 Mean Degree of Cure ≥95 % ASTM E2160 Mean Measured Cross-Sectional Area Table 3 ASTM D7205/D7205M, subsection 11.2.5.1 GuaranteedB Ultimate Tensile Force Table 3 ASTM D7205/D7205M Mean Tensile Modulus of Elasticity ≥44,800 MPa [6 500 000 psi] ASTM D7205/D7205M Mean Ultimate Tensile Strain ≥1.1 % ASTM D7205/D7205M GuaranteedB Transverse Shear Strength ≥131 MPa [19 000 psi] ASTM D7617/D7617M GuaranteedB Bond Strength ≥7.6 MPa [1100 psi] ASTM D7913/D7913M Mean Moisture Absorption to Saturation ≤1.0 % to saturation at 50 °C [122 °F] ASTM D570, subsection 7.4 Mean Alkaline Resistance ≥80 % of initial mean ultimate tensile force following 90 days at 60 °C [140 °F] ASTM D7705/D7705M, Procedure A GuaranteedB Ultimate Tensile Force of Bent Portion of Bar ≥60 % of the values in Table 3 ASTM D7914/D7914M(A) For the determination of the mean and guaranteed properties, at least 24 samples shall be obtained in groups of eight or more from three or more different pr