Experimental and Numerical Investigation of Different Types of Jacketing Effect on Retrofitting RC Short Columns Using ECC Concrete

Abstract

Given the deterioration of civil infrastructure throughout the world, developing more efficient repair and strengthening is essential. Jacketing is one of the most common methods for retrofitting reinforced concrete (RC) columns. Notably, using engineered cementitious composite (ECC) within the jacketing area increases the bearing capacity and significantly enhances the ductility of the columns. The recent development of ECC concrete with suitable compressive strength and higher ductility of about 5 % can significantly enhance the performance of reinforced concrete structures. The behavior of retrofitted RC columns depends heavily on the cohesion between the jacket and the original column as well as the mechanical properties of the jacketing materials. This study investigates jacketed square and circular RC columns using ECC and conventional/normal concrete (NC) using different casing techniques to retrofit RC columns, namely galvanized mesh, U and L-shape joints, removing the cover, core drilling, and integrated models. All specimens were subjected to a compression test. The results indicate that in both square and circular specimens, the use of ECC as a super ductile material and vertical U-shaped elements to connect the longitudinal rebars of the casing and the core leads to much higher ductility and bearing capacity than in NC specimens. These elements also showed suitable ductility because of using ECC as a super ductile material. In order to optimize these methods, finite element analysis (FEA) was conducted using Abaqus software to verify experimental models, as well as a parametric study to achieve an optimum design of the jacketing.

Experimental studies on tensile behavior of reinforced engineered cementitious composite members with double steel rebars

“…13,14 In addition, ECC has a great potential as a structural strengthening/repairing material in engineering application. [15][16][17][18] To date, the tensile behavior of reinforced concrete and other types of reinforced fiber concrete has been widely studied experimentally and analytically. 4,[19][20][21][22][23][24][25][26] Moreno et al 21,22 conducted a series of uniaxial tension tests on reinforced concrete and reinforced ECC members.…”

“…Therefore, ECC can be used in reinforced concrete structures in place of conventional concrete to significantly improve postracking behavior and seismic behavior of structures 13,14 . In addition, ECC has a great potential as a structural strengthening/repairing material in engineering application 15–18 …”

Size Effect on Flexural and Fracture Properties of Polypropylene Fiber-reinforced Engineered Cementitious Composite

“…During the last decades, the engineered cementitious composite (ECC) has drawn the attention of many scholars and designers in various structures, such as high-rise buildings, bridge decks, tunnels, and highways, in different parts of the world [1][2][3][4]. ECC is a particular class of ultra-high ductile fiber-reinforced cementitious composite, which exhibits significant performance in the strain-hardening stage due to triggering multiple cracks with width less than 100 µm while keeping the volume content of randomly distributed short fibers no more than 2% [3,5].…”

Effect of ECC layer thickness and reinforcement ratio on the load carrying capacity of steel‐reinforced composite beams

“…It is also used in the jacketing technique for the strengthening of deficit RC structures. 10 Although numerous studies have been carried out to investigate the flexural behavior of ECC structural members, [11][12][13][14] very few studies were conducted on steelreinforced concrete beams with ECC replacement, which are expected to be more economical and more likely to be applied in practical conditions. Reinforced composite beams were developed with partial replacement of concrete using ECC in its tensile region for improving flexural strength and limiting crack widening and propagation.…”

“…In recent times, ECC has been successfully implemented in the construction of infrastructural assets, such as earthquake‐resistant buildings, link slab or overlays in bridge deck, coupling beam in high‐rise building, and so forth. It is also used in the jacketing technique for the strengthening of deficit RC structures 10 …”