scholarly journals Behavior predictions of deep beams with short straight bar anchorages using strut-and-tie models and nonlinear analysis

2016 ◽  
Vol 9 (5) ◽  
pp. 710-721
Author(s):  
R. A. SOUZA ◽  
S. BREÑA
Keyword(s):  
Nonlinear Analysis ◽  
Longitudinal Reinforcement ◽  
Deep Beams ◽  
Bond Slip ◽  
Crack Control ◽  
Strength Factor ◽  
Strut And Tie ◽  
Effective Strength ◽  
Laboratory Test Results ◽  
Strut And Tie Model

Abstract This paper investigates the laboratory test results of 12 deep beams available in the literature, where the longitudinal reinforcement was anchored into the support using short straight bar anchorages. Four different specimen groups with three different shear span-to-depth ratios (a/d) were selected and most of the deep beams failed by strut crushing after yielding of the main longitudinal reinforcement. In order to investigate the behavior of the selected deep beams, an enhanced strut-and-tie model assuming geometrical adaptability (possibility of update in the dimensions of the struts and ties as the main tie starts to yield) is proposed. The analytical results obtained using this approach may be considered as much as accurate than some conducted complex nonlinear analysis considering smeared fixed cracking model and bond-slip behavior. However, an improvement on the effective strength factor of bottle-shaped struts by means of an iterative strut-and-tie model is needed, once the effective strength factor prescribed by NBR6118 (2014) has shown to be over conservative for all ranges of span-to-depth ratio (a/d) investigated. Finally, the obtained results indicated that short bar anchorages did not seem to influence significantly the shear strength of the deep beams investigated, especially the strength of bottled-shaped struts when appropriate crack control reinforcement is present.

Experimental Study on Shear Behavior of Prestressed Concrete Deep Beams with Draped Tendons

2010 ◽  
Vol 163-167 ◽  
pp. 1339-1342
Author(s):  
Guo Lin Wang ◽  
Shao Ping Meng
Keyword(s):  
Shear Strength ◽  
Prestressed Concrete ◽  
Design Method ◽  
Shear Behavior ◽  
Longitudinal Reinforcement ◽  
Test Results ◽  
Normal Amount ◽  
Deep Beams ◽  
Strut And Tie ◽  
Strut And Tie Model

Two simply supported deep beams were tested, one with draped prestresssing tendons and the other without for reference. Shear behavior and the prestressing effect were focused on. The test results showed that deep beams with the longitudinal reinforcement ratio of a normal amount were inclined to fail in flexural-shear, and the prestressing could greatly increase both the cracking load and the shear strength. Beside, the Modified Strut-and-Tie Model (MSTM) and the sectional design method from China Code (GB02) have also been adopted for predictions. The comparisons indicates that the MSTM can not only well predict the shear strengths of deep beams, but also well account for the prestressing effect, while the sectional design method seems so conservative due to its not properly considering the shear mechanism of deep beams. It can be concluded that the MSTM is capable of predicting the shear strength of PC deep beams with draped tendons and thus can be employed in practical designs.

Study on Mechanical Behaviors and Calculation of Shear Strength of Steel Truss Reinforced Concrete Deep Beams

2011 ◽  
Vol 243-249 ◽  
pp. 514-520
Author(s):  
Chun Yang ◽  
Ming Ji He ◽  
Jian Cai ◽  
Yan Sheng Huang ◽  
Yi Wu
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Experimental Investigations ◽  
Deep Beam ◽  
Deep Beams ◽  
Steel Reinforced Concrete ◽  
Strut And Tie ◽  
Steel Truss ◽  
Mechanical Performances ◽  
Strut And Tie Model

Based on strut-and-tie model (STM) in deep beams, steel truss reinforced concrete (STRC) deep beam was developed. Experimental investigations of mechanical performances of STRC deep beams were carried out, and results show that STRC deep beam is of high ultimate bearing capacity, large rigidity and good ductility; Strut-and-tie force transference model is formed in STRC deep beams, and loads can be transferred in the shortest and direct way. Then Steel reinforced concrete (SRC) strut-and-tie model (SSTM) for determining the shear strength of STRC deep beams is proposed. The contribution of SRC diagonal strut, longitudinal reinforcements, stirrups and web reinforcements to the shear strength of STRC deep beams are determined with consideration of softened effects of concrete, and for safe consideration, superposition theory is employed for SRC struts. Computer programs are developed to calculate the shear strength of STRC deep beams and verified by experimental results.

Experimental Study on Deep Four-Pile Caps with Different Reinforcement Layouts Based on 3D Strut-and-Tie Analogy

2008 ◽  
Vol 400-402 ◽  
pp. 917-922 ◽  
Author(s):  
Qian Gu ◽  
Cheng Fang Sun ◽  
Shao Min Peng
Keyword(s):  
Load Capacity ◽  
Longitudinal Reinforcement ◽  
Test Results ◽  
Test Procedures ◽  
Strut And Tie ◽  
Pile Cap ◽  
Scale Ratio ◽  
Pile Caps ◽  
Strut And Tie Model ◽  
Distributed Reinforcement

Based on 3D strut-and-tie analogy developed for analyzing the load-transferring mechanism of deep pile cap, this paper focuses on the effect of different longitudinal reinforcement layouts at the lower part of cap on the mechanical behaviors of deep four-pile cap. Besides a common layout of uniformly distributed reinforcement by the flexural theory, three different layouts of concentrated reinforcement over piles were designed by 3D strut-and-tie analogy. All specimens were limited in same reinforcement percentages, dimensions, materials and test procedures. Four specimens with the scale ratio of 1/5 were tested under the statically incremental gravity loading. The load capacity, deflection, strain of longitudinal reinforcement of specimens were measured, and the failure mode, crack propagation, deformation of specimens and stress distribution of reinforcement were analyzed. Through comparisons of the test results among all specimens, it was found that deep pile cap failed in shear and corner-pile punching whether with concentrated or uniform reinforcement, and the reinforcement concentrated over each two adjacent piles, similar to the tension bars in the strut-and-tie model, had considerable advantages than common uniform reinforcement layout. The ultimate strength of deep pile cap with concentrated reinforcement was significantly increased, while the improvement of deformation resistance and brittleness of deep pile cap was limited. According to above findings, the appropriate reinforcement layouts for deep pile cap were suggested in this paper.

scholarly journals Composite Strut and Tie Model for Reinforced Concrete Deep Beams

2009 ◽  
Vol 7 (1) ◽  
pp. 97-109 ◽  
Author(s):  
Kil-Hee Kim ◽  
Woo-Bum Kim ◽  
Jin-Man Kim ◽  
Sang-Woo Kim
Keyword(s):  
Reinforced Concrete ◽  
Deep Beams ◽  
Strut And Tie ◽  
Strut And Tie Model

scholarly journals Study on an Optimal Strut-And-Tie Model for Concrete Deep Beams

2019 ◽  
Vol 9 (17) ◽  
pp. 3637
Author(s):  
Haitao Chen ◽  
Lai Wang ◽  
Jitao Zhong
Keyword(s):  
Carrying Capacity ◽  
Engineering Application ◽  
Load Carrying Capacity ◽  
Deep Beam ◽  
Structural Members ◽  
Deep Beams ◽  
Strut And Tie ◽  
Load Carrying ◽  
Strut And Tie Model ◽  
Reinforcement Design

The optimal strut-and-tie models (STMs) of two typical irregular concrete deep beams were constructed using evolutionary structural optimization and compared with those of previous studies. The reinforced concrete deep beam specimens were cast according to the reinforcement designs guided by different STMs. Eight irregular concrete deep beam specimens were experimentally investigated under stepped loading, and the differences in the amount of steel used, the load-carrying capacity, and the failure pattern of the different specimens were analyzed. The results show that the optimal STMs proposed in this study have significant advantages in terms of cost-effectiveness and can simultaneously ensure the load-carrying capacity, delay the crack propagation of irregular concrete deep beams, and reduce the amount of steel used in structural members. Therefore, they have an important engineering application value for the reinforcement design of irregular concrete deep beams.

Shear Behavior of Reinforced Concrete Deep Beams with Various Horizontal to Vertical Reinforcements and Shear Span-to-Effective Depth Ratios

2014 ◽  
Vol 931-932 ◽  
pp. 473-477
Author(s):  
Prach Amornpinnyo ◽  
Jaruek Teerawong
Keyword(s):  
Reinforced Concrete ◽  
Shear Behavior ◽  
Beam Specimen ◽  
Test Results ◽  
Deep Beams ◽  
Shear Span ◽  
Strut And Tie ◽  
Vertical Reinforcement ◽  
Effective Depth ◽  
Strut And Tie Model

This paper presents the test results on the shear behavior of reinforced concrete deep beams with six steel reinforcement configurations. They were designed in accordance with the method given in the ACI 318-11. The specimens were subjected to the single concentrated loading at mid-span. The horizontal to vertical reinforcement ratios and shear span-to-effective depth ratios were the variables studied. The shear span-to-effective depth ratios of the beam specimen were between 1.5 to 2.0. The strut-and-tie model was used for the analysis. The test results indicated that the first diagonal cracking load and the failure mode were controlled by the horizontal to vertical reinforcement ratios and the shear span-to-depth ratios. The tests consistently gave the strength values slightly less than those calculated by using the ACI model. A modified ACI model for strut-and-tie was thus proposed and was found to accurately fit the experimental results.

Effective Strength of Concrete Struts for a Three-dimensional Four-pile Cap Strut-and-Tie Model

2019 ◽  
Vol 31 (1) ◽  
pp. 49-59
Author(s):  
Young Mook Yun ◽  
Young-Jae Lee ◽  
Sung-Sik Park ◽  
Seong-Cheol Lee ◽  
Sung Gun Lim
Keyword(s):  
Three Dimensional ◽  
Strut And Tie ◽  
Effective Strength ◽  
Pile Cap ◽  
Strut And Tie Model
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