Behaviour of reinforced concrete deep beams in previous studies

Abstract

This paper is a comprehensive study of the reinforced concrete simple deep beams based on previous experimental and theoretical studies. Forevermore, it is a review of the methods of analysis that recommended by ACI code or suggested by some researchers. The main parameters that were taken into considerations were: shear span to effective depth ratio (a/d), amount of flexural reinforcement (ρ), web shear reinforcement (ρh and ρv ), steel fiber volumetric ratio (Vf), compressive strength of used concrete (f’c), existence of openings with different shapes and sizes in addition to strengthening them. Researchers found that increasing a/d ratio about 50-67% leads to decrease deep beam ultimate capacity by about 17-23%, respectively. Increasing ρ leads to decrease ductility. Increasing ρh and ρv or both, increases capacity by different ratios. Removing only ρv leads to a decrease in ultimate capacity by about 19%, removing only ρh leads to a decrease in ultimate capacity by about 10%, while removing both, leads to about 31% reduction in ultimate capacity. Using Vf = 0.4% causes increasing in cracking and ultimate capacity by about 33% and 11%, respectively, while using Vf = 0.8% causes increasing in cracking and ultimate capacity by about 64% and 33%, respectively. Increasing f’c about 50% leads to increase the ultimate capacity by about 39-52%. It was also found that opening existence decreases the ultimate capacity especially when they lie in the strut paths, more specifically, they decrease ultimate capacity by about 3-69%, while strengthening them by steel plates leads to increase ultimate capacity by about 9-27%.

Shear Resistance of Fibrous Reinforced Concrete Deep Beams with Opening – A Critical Review

“…Nowadays, reinforced concrete (RC) deep beams are common structural elements in modern constructions ranging from tall buildings to marine gravity structures [2][3][4][5]. They are also used as foundation beams, panel girders, and deep mesh walls in marine-type gravity concrete structures [3][4][5][6]. Deep beams are often used as load distribution elements in engineering structures such as deep girders, shear walls, bent caps (in the bridges), pile caps (in foundation), warehouses (bunker), and water tanks where the walls act as vertical beams that span between column supports [3][4][5][6][7].…”

“…They are also used as foundation beams, panel girders, and deep mesh walls in marine-type gravity concrete structures [3][4][5][6]. Deep beams are often used as load distribution elements in engineering structures such as deep girders, shear walls, bent caps (in the bridges), pile caps (in foundation), warehouses (bunker), and water tanks where the walls act as vertical beams that span between column supports [3][4][5][6][7]. Reinforced concrete (RC) deep beams transfer a load as a supported beam to the support through a compression mechanism [4].…”

“…The term deep beam applies to any beam with a sufficiently large depthspan ratio to cause a non-linearity in the distribution of elastic flexural stress over the depth of the beam and distribution of shear stress to be non-parabolic. In simple words, RC deep beams are structural members with a depth much greater than their span length, while the thickness of the vertical direction is much smaller than the depth or span [3][4][5][6]8]. According to the American Concrete Institute (ACI), 318-14 [9] definition, deep beams are structural members supported on the face and oppositely loaded on the other face so that compressive struts can develop between the support and the loads.…”

“…RC deep beams are considered a complex phenomenon, many experimental types of research have been performed previously, but the structural behavior of RC deep beams is still unreliable [4,6,7,10]. Most researchers have concluded that failure is significantly affected by its shear resistance (capacity) than flexural resistance [4][5][6][7][8][10][11][12][13][14]. Thus, shear behavior is the key point of this critical review.…”

Strut and Tie Modelling of Reinforced Concrete Deep Beams Under Static and Fixed Pulsating Loading

“…Deep beams are qualified by having a shear spandepth ratio (a/d) relatively small Figure 1, [3] thus, their behavior is dominant under shear rather than flexure and their capacity depends on the mode of application of load and supports condition. Many investigations have been conducted on the behavior of a simply supported RC deep beam under static loading [3,4], however, some RC deep beams are under the influence of pulsating loading such as the vibrating machine. Their behaviors are different when compared to the static loading [5].…”