Structural Behavior of GFRP-RC Bridge Deck Slabs Connected with UHPFRC Joints under Flexure and Shear

Abstract

Recently, the use of ultrahigh-performance fiber-reinforced-concrete (UHPFRC) closure joints between structural members has increased in accelerated bridge construction (ABC) applications. This paper presents an experimental study to investigate the structural behavior of UHPFRC closure joints between glass-fiber-reinforced-polymer reinforced-concrete (GFRP-RC) bridge-deck slabs. A total of seven full-scale specimens measuring 3,000-mm long × 1,000-mm wide × 225-mm thick were fabricated, comprised of a reference specimen without closure joints and six jointed specimens. The investigated parameters were: (1) the splice lengths (100, 150, and 200 mm with corresponding joint widths of 120, 170, and 220 mm, respectively); and (2) the reinforcement ratio (No. 15 and No. 20 GFRP bars with the same spacing). The specimens were tested up to failure in a cantilever-panel setup under monotonic line loading in which the UHPFRC closure joint was subjected to flexural and shear stresses. The test results are discussed and analyzed in terms of crack pattern, load–deflection response, crack width, GFRP reinforcement, and concrete strains. The test results show that a minimum splice length of 100 mm in 120 mm UHPFRC closure joints yielded adequate strength and performance until failure. The UHPFRC closure joints remained intact without visible cracks and maintained the continuity between the precast slabs.