Tensile characterization of glass FRP bars

The characterization of fiber reinforced polymer (FRP) bars for concrete reinforcement is necessary for design purposes as required by structural engineers, and for quality control/optimization purposes as required by bar manufacturers. This paper reports on a test protocol and the results obtained from a replicated experiment intended to yield a statistically valid estimate of the distribution of tensile strength in FRP bars. Four selected types of glass FRP (GFRP) bars with the same diameter were tested. In total, 32 bars from the same manufacturer were investigated. Instead of a polymeric resin-based anchor, a steel pipe filled with expansive cementitious grout was used as the end restrainer. An experiment based on a randomized complete block design was carried out to obtain data for statistical analysis. The analysis was carried out using a commercially available data analysis software program. This research project indicates that the suggested test procedure provides reliable data for tensile characterization and confirms that a Gaussian distribution can represent the tensile strength of the GFRP bars as tested.