Experimental Analysis of Continuous Beams Made of Self-Compacting Concrete (Scc) Strengthened with Fiber Reinforced Polymer (Frp) Materials

Abstract

Strengthening of concrete structures is applied as a solution for various deterioration problems in civil engineering practice. This also refers to the structures made of self-compacting concrete (SCC), which is increasingly in use, but there is a lack of research in this field. This paper presents an experimental analysis of flexural behavior of reinforced concrete (RC) continuous beams made of SCC, strengthened with fiber reinforced polymer (FRP) materials (glass (GFRP) and carbon (CFRP) bars, CFRP laminates), by the use of near surface mounted (NSM) and externally bonded (EB) methods. Six two-span continuous beams of a total length of 3200 mm, with the span between supports of 1500 mm and 120/200 mm cross section, were subjected to short-term load and tested. The displacements of beams and the strains in concrete, steel reinforcement, FRP bars and tapes were recorded until failure under a monotonically increasing load. The ultimate load capacities of the strengthened beams were enhanced by 22% to 82% compared to the unstrengthened control beam. The ductility of beams strengthened with GFRP bars was satisfactory, while the ductility of beams strengthened with CFRP bars and tapes was very small, so the failure modes of these beams were brittle.

Improving the Structural Characteristics of Heavy Concrete by Combined Disperse Reinforcement

“…The results of experimental studies of the effect of a combination of various types of fibers and volume content on the strength and deformation characteristics of fiberreinforced concrete are presented in Figures [7][8][9][10][11] show that the highest compressive and tensile strengths in bending and elastic modulus, as well as the smallest ultimate deformations under axial compression and tension of fiber-reinforced concrete, are observed with the following combinations and volumetric contents of fiber fibers: steel-basalt (2%-2%), steel-polypropylene (2.5%-1.5%), polypropylene-basalt (1.5%-2.5%). Figures [7][8][9][10][11] show that the highest compressive and tensile strengths in bending and elastic modulus, as well as the smallest ultimate deformations under axial compression and tension of fiber-reinforced concrete, are observed with the following combinations and volumetric contents of fiber fibers: steel-basalt (2%-2%), steel-polypropylene (2.5%-1.5%), polypropylene-basalt (1.5%-2.5%). Figures [7][8][9][10][11] show that the highest compressive and tensile strengths in bending and elastic modulus, as well as the smallest ultimate deformations under axial compression and tension of fiber-reinforced concrete, are observed with the following combinations and volumetric contents of fiber fibers: steel-basalt (2%-2%), steel-polypropylene (2.5%-1.5%), polypropylene-basalt (1.5%-2.5%).…”

“…Figures [7][8][9][10][11] show that the highest compressive and tensile strengths in bending and elastic modulus, as well as the smallest ultimate deformations under axial compression and tension of fiber-reinforced concrete, are observed with the following combinations and volumetric contents of fiber fibers: steel-basalt (2%-2%), steel-polypropylene (2.5%-1.5%), polypropylene-basalt (1.5%-2.5%). Figures [7][8][9][10][11] show that the highest compressive and tensile strengths in bending and elastic modulus, as well as the smallest ultimate deformations under axial compression and tension of fiber-reinforced concrete, are observed with the following combinations and volumetric contents of fiber fibers: steel-basalt (2%-2%), steel-polypropylene (2.5%-1.5%), polypropylene-basalt (1.5%-2.5%).…”

“…In [10], an experimental analysis of the bending behavior of reinforced concrete beams reinforced with fibrous polymer materials using surface mounting and external bonding methods is presented. Six double-span beams with a total length of 3200 mm and a 120/200 mm cross-section were tested under short-term and monotonically increasing loads.…”

Numerical Analysis of an Innovative Double-Strap Joint for the Splicing of Near-Surface Mounted Fiber-Reinforced Polymer Bars for Reinforced Concrete Beam Strengthening

“…The EB-FRP method appeared earlier and has wider applications because of its practical values [4]. On the other hand, the NSM FRP method has significant advantages, which have been shown in many studies [5][6][7][8][9]. The basic advantage of the NSM FRP technique of strengthening compared to that of EB-FRP is based on its better adhesiveness, which mostly affects the ultimate strengths of strengthened structures [10][11][12].…”