GFRP composite bars for splicing prestressed precast concrete piles: Design and experimental investigation

Abstract

Glass Fiber Reinforced Polymer (GFRP) composite bars were investigated in this study as a corrosion-resistant dowel for splicing prestressed precast concrete piles (PPCPs). In addition to their durability and good mechanical performance, GFRP bars show cost advantage when compared to other corrosion-resistant material. Using available design guides for FRP-reinforced concrete sections, a typical epoxy bonded dowel splice using GFRP bars was designed for an 18 × 18 in (457 × 457 mm) PPCP. In order to validate the adopted design procedure and to investigate the effectiveness of GFRP reinforcing bars as bonded dowels for pile splice design, 10 full-scale PPCP specimens of 18 × 18 in (457 × 457 mm) cross-section with a total length of 28 ft (8.5 m) were designed, fabricated, and tested at the Florida Department of Transportation (FDOT) Structures Research Center. In these specimens, three different materials for dowels; GFRP reinforcing bars, Carbon Fiber Reinforced Polymer (CFRP) strand, and traditional carbon-steel reinforcing bars were used in combination with CFRP and steel prestressing strands for PPCPs for both unforeseen and preplanned drivable splicing cases. The focus of this study was on the flexural performance at the splice. The experimental results show that the proposed epoxy GFRP dowel pile splice can match the required design flexural resistance for a preplanned PPCP carbon-steel pile splice. The laboratory tests performed in this research validates the new design procedure for the GFRP dowel splice. The design flexural resistance for the GFRP dowel splice calculated by the new procedure provides 68 % of 245 kip-ft (332.2 kNm), the flexural resistance required by the FDOT design specifications for mechanical preplanned splices. This research will help to improve the standard designs and construction specifications.