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Abstract
Due to limitations in operation, shipping difficulties, and unforeseen soil conditions, it often happens that splicing of precast-prestressed concrete pile (PPCP) segments has to be performed at the construction site to achieve longer lengths. In order to splice PPCPs, Glass fiber reinforced polymer (GFRP), Carbon Fiber Reinforced Polymer (CFRP), and Stainless Steel (SS) dowels can be used as corrosion-resistant bars. In addition to their durability and superb mechanical performance, GFRP bars show cost advantage when compared to other corrosion-resistant materials. The objective of this study is to investigate the flexural behavior and effectiveness of the GFRP dowel and compare its performance to CFRP and conventional carbon steel dowels. In this research, a design procedure was developed using available design codes for FRP-reinforced concrete sections for epoxy GFRP dowel pile splices. In order to validate the design procedure and investigate the effectiveness of the GFRP dowels as well as to compare to dowels of other materials, 10 full-scale PPCP specimens of 18 18 in cross-section with a total length of 28 ft were fabricated and tested at the Florida Department of Transportation (FDOT) Structures Laboratory. For the PPCP specimens, three different materials of GFRP, CFRP, and traditional carbon steel were used as dowels in combination with CFRP and steel prestressing strands for both drivable unforeseen and preplanned cases. The focus of this study was on the flexural performance at the splice. The experimental results show that the proposed design procedure underestimates the nominal moment capacities for GFRP dowel splices by an average of approximately 14% when compared to the test results. Furthermore, three distinctive failure types were observed in laboratory tests. As the first failure mode, unforeseen splice specimens failed by splitting and bond failure in the female segments due to short dowel lengths. In the second failure mode, specimens for which GFRP dowel was used in combination with piles using CFRP prestressing strands failed by flexural cracking and debonding in the male segment near the end of the GFRP dowel. This failure mode could be an indication of inadequate bond length for CFRP strands. Third failure mode dominating the remaining of the specimens was a classical flexural mode with the concrete crushing in the compression zone at splice section. To facilitate the design of pile splices with varying parameters and sizes for all types of materials and configurations, the design procedure was implemented in Mathcad to develop a stand-alone software tool. This tool provides the user with nominal and design flexural strengths, M-N interaction curves, and complete detailing of the splice zone. This research has developed new splice design and drawings for FRP dowel splices as part of the FDOT standard plans and construction specifications