Lateral cyclic behavior of interior two-way concrete slab–column connections reinforced with GFRP bars. (15th April 2020)

• Record Type: Journal Article
• Authors: Eladawy, Mohamed; Hassan, Mohamed; Benmokrane, Brahim; Ferrier, Emmanuel
• Is Part Of: Engineering structures. Volume 209(2020)
• Publication Date: 2020-04-15
• Subjects: Punching shear -- GFRP-reinforced concrete -- Slab–column connection -- Stirrups -- Shear reinforcement -- High-strength concrete -- Drift capacity -- Cyclic loading -- Ductility; Structural engineering -- Periodicals; Structural analysis (Engineering) -- Periodicals; Construction, Technique de la -- Périodiques; Génie parasismique -- Périodiques; Pression du vent -- Périodiques; Earthquake engineering; Structural engineering; Wind-pressure; Periodicals; 624.105
• DOI: 10.1016/j.engstruct.2019.109978
• Languages: English
• ISSNs: 0141-0296

Abstract

Highlights: The feasibility of using FRP as internal reinforcement in reinforced-concrete members to resist seismic loads. The punching-shear performance of interior two-way slab–column connections reinforced with glass-fiber-reinforced-polymer (GFRP) bars under lateral cyclic loads. The effect of using high-strength concrete on the seismic behavior of interior slab–column connections. The influence of providing closed GFRP stirrups in the vicinity of columns on the seismic performance of the slab–column connection. The ability of GFRP-RC slab–column connections to withstand a high interstory drift ratio. Abstract: In flat plates, the use of high-strength concrete (HSC) in the slabs, and the presence of shear reinforcement in the vicinity of columns are considered effective, economical, and practical solutions for enhancing the punching shear performance of slabs. This paper presents the first-ever experimental results for interior concrete slab–column connections reinforced with glass-fiber-reinforced-polymer (GFRP) bars subjected to a combination of gravity and lateral reversed cyclic loads. Four full-scale slabs measured 2500 × 2500 mm with a thickness of 200 mm, and 300 mm square column extending 700 mm above and below the slab surfaces specimens were constructed and tested until failure. The main test variables were (i) flexural-reinforcement type (GFRP and steel bars); (ii) slab's concrete compressive strength (NSC and HSC); and (iii) the use of GFRP shear reinforcement. All the tested specimens demonstrated adequate strength, deformation capacity, drift ductility indices, dissipated energy, and connection stiffness. The GFRP-reinforced NSC specimen without shear reinforcement showed adequate ability to withstand interstory drift up to 2.25% without punching failure. The GFRP-reinforced HSC specimen without shear reinforcement had a 33% higher lateral deformation and moment-transfer capacities compared to the GFRP-reinforced NSC specimen. The provision of GFRP-stirrups in the slab–column connection significantly influenced slab overall performance. The shear-reinforced specimen was able to sustain lateral drifts as high as 5% with no more than a 20% decrease in the moment carrying capacity. Moreover, the shear-reinforced slab was able to sustain the gravity load until the end of testing and only exhibited softer punching-shear failure with a gradual decrease in lateral loads.