Experimental study on fracture behavior of notched self‐consolidating concrete beam strengthened with off‐axis CFRP sheet

Abstract

In this study, the effects of fiber orientation within the carbon fiber reinforced (CFRP) sheets, on the fracture mode and crack growth of specimens were investigated by constructing five groups of initially notched self‐consolidating concrete beams, and strengthening them with CFRP sheets in the tensile area. Furthermore, the bearing capacity, strain variation along the sheet, crack mouth opening, and the midspan displacement were recorded by varying the height of the beams and the initial notch lengths. The results indicate that the load‐crack mouth opening curves have two peak load points. First, the applied load increases up to one peak value and then there is a drop in the load‐caring capacity. Afterwards, the applied load is improved to another peak value due to the relatively high cohesive effect of the CFRP sheet. The results show that as the height of the beam section increases, or the initial notch length decreases, the first and the second peak loads increase. By comparing the specimens with different fiber angles in each group, it was observed that the specimen with fiber angle 0° has a higher capacity relative to other angles, yet its failure occurs in a lower displacement. Furthermore, with the help of finite element software and nonlinear static analysis, the behavior of the aforementioned beams including the stress and strain distributions in the CFRP sheet, and the sheet‐to‐concrete bond zone have been examined and compared with the existing experimental results for validation.

Wrapping and anchoring effects on CFRP strengthened reinforced concrete arches subjected to blast loads

“…FRP is a high‐performance composite material, which is composed of certain proportions of fiber material and resin matrix material. Because of the properties of high strength and stiffness‐weight ratio, superior corrosion resistance, and on‐field ease of application, the use of FRP composites as external confinement for concrete structures has received a great deal of attention in the last two decades, 4,5 and it has also been applied to strengthen arch structures for years 6 . The FRP strengthening is effective in improving load‐carrying capacity, decreasing structural deformation, and improving structural stability of masonry arches 7,8 and RC arches 9,10 .…”

Retrofitting of RC Beams using Reinforced Self-compacting Concrete Jackets Containing Aluminum Oxide Nanoparticles

“…Various studies have been conducted on retrofitting of RC beams. Sangi et al [10] made 35 self-compacting concrete beams and retrofitted them with CFRP sheets in the tensile zone (bottom surface of the beam). Also, numerical simulation was used to investigate the fracture mode and cracks distribution in the samples.…”

“…Also, numerical simulation was used to investigate the fracture mode and cracks distribution in the samples. It was indicated that the retrofitted beam with CFRP angle 0° has more capacity *Corresponding Author Email: Sayari_arash@yahoo.com (A. Sayari) in comparison to other specimens [10]. Shadmand et al [11] introduced a proposed method for retrofitting RC beams in which steel-concrete composite jackets containing steel fibers were used.…”

“…Oltulu and Sahin [28] investigated the effect of Nano silica, ANPs, and iron oxide nanoparticles separately and in combination with fly ash and silica fume. The results showed that the best performance in terms of compressive strength and permeability was obtained in the presence of 1.25% ANPs [10]. Behfarnia and Salemi [29] investigated the effects of nano silica particles and ANPs on the resistance of ordinary concrete to freezing.…”