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

Abstract

The purpose of this study was to introduce a proposed method to retrofit RC beams. For this purpose self-compacting concrete containing aluminium oxide nanoparticles (ANPs) and silica fume (SF) was used in RC jackets. The laboratory experiment and numerical simulation were used to investigate the behavior of the beams. The experimental variables were included the amount of ANPs used in the jackets (0 and 2.5% by weight of cement) and the surface interaction between beam and jacket (75% and 100% of the side and bottom surfaces of the beam). Five RC beams with a length of 1.4 m and the same dimensions were made and subjected to four-point loading. After completing the laboratory steps, RC beams were simulated according to laboratory conditions using the finite element method and ABAQUS software. After verifying the used method, parametric analysis was performed and parameters such as beam span length (1.5, 3, 4.5 m), concrete jacket thickness (4, 8, and 12 cm), and the diameter of the bars used in the jacket (8, 10 and 12 mm) were examined. The results showed that the use of RC jackets containing ANPs, depending on the jacket thickness, the diameter of the bars used in the jacket, and the length of the beam span increased the beams flexural strength by 155 to 447%. It was observed that the crushing of concrete without nanoparticles compared to concrete contain nanoparticles is more severe because nanoparticles affected the concrete matrix and reduced its crushing in RC jackets.

Experimental Comparison of Different Types of FRP Wrapping in Repairing of RC Deep Beams with Circular Openings

“…The adhesive utilized to bond the FRP sheets was a two-part adhesive consisting of hardener and resin. According to the manufacturer's catalog, this adhesive's density and tensile strength are equal to 1.11 g/cm 3 and 76.1 MPa, respectively.…”

“…One of the topics that construction industry experts have considered in recent years is repairing existing structures that are still in operation after their lifetime. Errors in construction and execution, the weakness of old regulations, increasing the number of storys, and the impact of destructive environmental factors are among the reasons for the need for retrofitting computational errors [1][2][3].…”

Strengthening of RC Beams Using SCC Jacket Consisting of Glass Fiber and Fiber-Silica Fume Composite Gel

“…Nowadays, strengthening and rehabilitation of beams, which are essential members of structural frames, have been investigated. Increasing flexural or shear *Corresponding Author Email: Maleki.ah@yahoo.com (A. Maleki) capacity, control of deformation, and cracking are the main goals of strengthening these members [10][11][12].…”

“…They showed that steel fiber can decrease the cracks and improve the performance of the RC jacket [11]. Faez et al [12] examined the strengthened beams with RC jacket. They used aluminum oxide nanoparticles and silica fume in jacket.…”

“…They used aluminum oxide nanoparticles and silica fume in jacket. The proposed method enhanced the bearing load about 155 to 447% [12]. Maraq et al [17] investigated the flexural behavior of reinforced concrete beams with steel wire mesh and self-compacting concrete jacket.…”