Splice Strength of Staggered and Non-Staggered Bundled Glass Fiber-Reinforced Polymer Reinforcing Bars in Concrete

摘要

While bundling of reinforcing bars in concrete is inevitable infield applications, the behavior of lap-spliced glass fiber-reinforced polymer (GFRP) bars in bundles has not yet been fully investigated. Therefore, this study aimed at elaborating on the splice strength of bundled GFRP bars in concrete under tension. Twelve full-scale beams with different staggering patterns, splice lengths, and GFRP bar sizes were tested under a monotonically increasing load using a four-point bending setup. The test results indicated that staggering had a pronounced effect on the bond strength of the three-bar bundle, although it was insignificant for splices of single- and two-bar bundles. Moreover; the bond strength was found to be dependent on the number of bars within a bundle as the splice strength was reduced by increasing the number of bundled bars. The reliability of the current provisions in CSA S806-12 and the applicability of the provisions in ACI 318-14 relating to GFRP bars was assessed, and design recommendations were made based on the experimental findings. The recommendations herein may support the work of the North American technical committees engaged in the development of standards and design provisions for development and lap splice lengths of bundled reinforcement in concrete members reinforced with GFRP bars.