Comparison between ASTM D7205 and CSA S806 Tensile-Testing Methods for Glass Fiber–Reinforced Polymer Bars

The standards ASTM D7205/D7205M-06 and CSA S806 contain the commonly used test methods for characterizing the tensile properties of glass fiber–reinforced polymer (GFRP) bars for use as reinforcement in concrete structures. These standards, however, use different anchor dimensions and loading rates, thereby possibly yielding different properties for the same type of fiber-reinforced polymer (FRP) bars. This paper assessed the results of a four-laboratory testing program comparing the sample preparation methods and test results according to ASTM D7205 and CSA S806. Each laboratory tested at least 10 samples prepared according to the recommendations in Annex A of the ASTM standard and Annex B of the Canadian Standards Association (CSA) standard. Each type of sample was prepared by a single laboratory to minimize variation among the test specimens. The results show a statistically significant difference between the tensile strength measured by using the CSA and ASTM provisions. Regardless of specimen preparation, the modulus of elasticity of the GFRP bars was the same with both test standards, but the ASTM standard returned a wider variation than did the CSA.