Composite Strut and Tie Model for Reinforced Concrete Deep Beams

Abstract

Monotonic shear loading tests were conducted on three half-scaled reinforced concrete deep beams with shear span-todepth ratios of 0.5 to 0.75. The obtained test results were investigated in detail based on the experimental measurements and finite element analysis. From these investigations, a new macro model for deep beams was established. This model is composed of two crooked main struts formed between both beam end sections and branched-off sub struts. The compressive force introduced to main struts balances the flexural compression and the external shear force. The bond stress of the longitudinal reinforcement and the tensile force of the stirrup produce the diagonal compression in the sub strut.Theoretically predicted shear strengths of tested deep beams showed good agreement with experimentally observed shear strengths, where the effective strength of concrete was assumed to be 75% of the cylinder strength.

A Simple Approach to Predict the Shear Capacity and Failure Mode of Fix-ended Reinforced Concrete Deep Beams based on Experimental Study

“…Shear failure of the beam occurs when the concentrated flow of stresses along the diagonal strut surpasses the compressive capacity of the cracked reinforced concrete in the panel. The influence of the softened effect on concrete is thus considered for concrete strength [29]. This model is called the softened strut-and-tie model since it considers the softening effect, which weakens the concrete strength.…”

“…The model was used to simulate the load capacity and failure mode of 31 additional experimental tests. These experimental tests are including; Subedi and Arabzadeh [3] involving 16 fixed-end RC deep beams, three specimens of Kim et al [29], Hidalgo et al [30], and Yang et al [31]. Table 4 shows the summary of the experimental tests included in this study.…”

“…In this group, the average strength ratio was 1.18 so this group was good agreement with the proposed STM model. The third category also was 3 fixed end deep deem that was tested under monotonic loading by Kim et al [29] the AVG. of this group was 1.12.…”

The GBESO Method Based on FEA with Discrete Models and Application for Aided Design to Members in RC D-Region

“…Reinforced concrete (RC) D-region, characterized by complex stress fields, includes various members (e.g., deep beams and corbels). Recent design methods for these members predominantly relied on the Strut-and-Tie Model (STM) method (Kim et al 2009;Salem and Maekawa 2006), in which the construction of the STM played a pivotal role. Conventional STM construction methods which only emphasize equilibrium conditions without considering deformation compatibility often result in non-unique models and corresponding difficulties in model determination, thus significantly hindering the widespread application for STM method.…”

Effect of Detailing of Web Reinforcement on the Behavior of Bottle-shaped Struts

“…Despite numerous researches and a number of code recommendations, the shear cracking mechanism and the role of web reinforcement on the shear cracking behavior are not fully understood (Kim et al 2009;Zakaria et al 2009). Although researchers (De Silva et al 2008;Zakaria et al 2009) have studied in detail the role of vertical stirrups on the shear cracking behavior of beams, the contribution of horizontal web reinforcement has been overlooked.…”