Experimental Investigation on Effect of Aspect Ratio on Behavior of Isolated Reinforced Concrete Struts

Strength prediction of a bottle-shaped strut for evaluating the shear capacity of reinforced concrete deep beam

“…Dhahir [11,13] proposed m = 6 to calculate the compression capacity of the bottle-shaped strut. Ghanei et al [30] concluded from an experimental and analytical investigation that the aspect ratio of a bottle-shaped strut influences the dispersion of compressive stress. Sahoo et al [29] conducted an experimental and analytical analysis of bottle-shaped struts and concluded that the bearing area of the applied load has a substantial impact on the dispersion of compression in the bottle-shaped strut.…”

“…The proposed STM model considers the effect of reinforcement on strength up to 0.84% and thereafter becomes constant as the efficiency factor equals unity (1). The compressive force dispersion in ACI 318-14 is specified as a slope of 2 parallel to 1 vertical (m = 2), whereas the actual dispersion depends on the geometry of the panel and the width of the loading plate [29,30,37] The proposed STM evaluates the slope 'm' based on the relation proposed by EC2 [equations ( 14) and (15)], that considers the width of the loading area and geometry of the panel. In this case, 'm' comes out to be 6.90, which shows that the slope, m, used by ACI 318-14 is substantially flatter, resulting in a conservative estimate of compressive strength.…”

“…In the recent past, different analytical models were proposed to evaluate the efficiency of the bottle-shaped strut [9,[11][12][13][22][23][24][25][26][27]. Some experimental and analytical research studies have also been carried out to investigate the behaviour of the bottle-shaped struts by testing RC concrete panels by loading them in the plane of the panels and suggesting analytical models to determine the efficiency of struts to evaluate the ultimate strength of compression struts [23,[28][29][30]. Ismail et al [31] investigated twenty-four (24) specimens of deep RC beams experimentally and concluded that the influence of web reinforcement ratio, shear span to depth ratio, and compressive strength of concrete should be considered for shear capacity prediction.…”

Study on Strut and Node Behavior in Strut-and-Tie Modeling

“…Their research investigated the effect of aspect ratio on the behavior of bottle-shaped struts. One of their specimens with an aspect ratio of 2.0 is shown in Figure 2 Ghanei and Aghayari [22] also tested vertically-oriented concrete panels with different dimensions and reinforcement; the failure of three of these panels is shown in Figure 2 [22] The authors of these studies all concluded that the stress can spread outward in bottleshaped struts, which will create transverse tensile stress. Because concrete is weaker in tension than compression, the bottle-shaped struts are weaker than prismatic one.…”