scholarly journals The load-bearing behaviour of a reinforced concrete beam investigated by optical measuring techniques

2021 ◽  
Vol 54 (3) ◽  
Author(s):  
Götz Hüsken ◽  
Stephan Pirskawetz ◽  
Detlef Hofmann ◽  
Frank Basedau ◽  
Klaus-Peter Gründer ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Failure Modes ◽  
Shear Failure ◽  
Reinforced Concrete Beam ◽  
Image Correlation ◽  
Fibre Bragg Grating ◽  
Load Bearing ◽  
Measuring Techniques ◽  
Deformation Measurements

AbstractBending beams and slabs are typical examples for structural elements used for reinforced concrete structures such as bridge girders, T-beams and bridge decks. Their strength related failure modes at maximum loading can be divided into bending and shear failure. The failure of beams loaded in bending can occur with or without indication. Therefore, conventional design concepts aim on failure modes with sufficient indication (e.g. large deflections or cracks), as it occurs in the case of secondary flexural compression failure. These indicating factors can also be used for Structural Health Monitoring (SHM) of civil infrastructure systems (e.g. bridges) to identify structural changes. In this context, non-destructive testing (NDT) methods offer different techniques for measuring deflections or crack formation and opening. However, profound knowledge on the determining failure modes of bending beams and their detection by NDT methods is required for the reliable application of SHM. Different NDT methods have been used in this study for analysing the load-bearing behaviour of a reinforced concrete beam in bending. The different measuring techniques are briefly described and their applicability is discussed by means of experimental results. For this purpose, the load-bearing behaviour of a reinforced concrete beam having a span of 2.75 m was investigated in a four-point bending flexural test at laboratory scale. The focus is on the characterization of determining failure modes by optical NDT and the comparison with classical measuring techniques (e.g. deformation measurements by displacement transducers). The bending beam was equipped with two single-mode (SM) sensor fibres. One fibre served as Distributed Optical Fibre Sensor (DOFS), whereas the other fibre contained Fibre Bragg Grating (FBG) sensors. In addition, optical deformation measurements using Digital Image Correlation (DIC) and Stereophotogrammetry (SP) were conducted.

Non-dimensional pressure–impulse diagrams for blast-loaded reinforced concrete beam columns referred to different failure modes

2018 ◽  
Vol 21 (14) ◽  
pp. 2114-2129 ◽  
Author(s):  
Runqing Yu ◽  
Diandian Zhang ◽  
Li Chen ◽  
Haichun Yan
Keyword(s):  
Reinforced Concrete ◽  
Dynamic Response ◽  
Concrete Beam ◽  
Failure Modes ◽  
Shear Failure ◽  
Reinforced Concrete Beam ◽  
Pressure Impulse ◽  
Beam Columns ◽  
Concrete Beam Columns ◽  
Bending Failure

The pressure–impulse diagram is commonly used to assess the damage level of structural components under explosion. Non-dimensional pressure–impulse diagrams referred to different failure modes was obtained using a new methodology in this article. Nine non-dimensional key parameters were first proposed on basis of the Euler beam theory. Considering the shear failure, an elastic–plastic method to calculate the dynamic response of reinforced concrete beam columns was then proposed for different failure modes. Three failure categories, for example, bending failure, shear failure, and combined shear and bending failure, were considered. The threshold between the three failure modes was determined using non-dimensional pressure–impulse curves. A systematic parametric study was conducted to investigate the effects of different non-dimensional parameters on the dynamic response and the failure modes of reinforced concrete beam column. Parametric study shows that the nine non-dimensional key parameters are sufficient to calculate the dynamic response of reinforced concrete beam columns. Moreover, present study shows that the tangent modulus of direct shear stress–slip relation has a great influence on the failure modes. Beam columns with a smaller tangent modulus are more likely to generate combined shear and bending failure mode.

scholarly journals Numerical Simulation on Reinforced Concrete Beam with Different Cover Size under Two Point Bending Load

2021 ◽  
Vol 7 (05) ◽  
pp. 39-43
Author(s):  
R Padma Rani & R Harshani
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Structural Analysis ◽  
Concrete Beam ◽  
Failure Modes ◽  
Equivalent Stress ◽  
Reinforced Concrete Beam ◽  
Simulation Software ◽  
Beam Specimen ◽  
Bending Load

Structural analysis is used to assess the behavior of engineering structures under the application of loads. Usually, structural analysis methods include analytical,experimental and numerical methods is used in thisproject, however, only Analytical method is used and the values are taken from literature reference, to get familiar with Finite Element Analysis (FEA) using ANSYS, this is done to acquire practical knowledge about of the effect of the cover. The aim is to identify different failure modes under a range of loading conditions by changing the cover size to get the data of various parameters such as deflection, stress etc. Study of cover helps to observe the stability, reliability and the overall strength of the structural beam. This project attempts made to study the effect of cover on the behavior of reinforced concrete beam. Forthis analytical study, the Reinforced concrete beam specimen of 2000x100x200mm was considered.ANSYS software is a suite of engineering simulation software, based on finite element method, which can solve problems ranging from linear analysis to nonlinear analysis. The Doubly reinforced beams weremodeled by using geometry. In this model,various covers are provided. The beam specimensused in this study were tested under two-point static loading condition until failure of the specimen. From theobtained resultconcluded that the total deformation and directional deformation values are low in 25mm cover compared to other cases but the equivalent stress value is low in 35mm cover size compared to 25mm cover size.

scholarly journals Load Bearing Capacity Calculation of the System “Reinforced Concrete Beam – Deformable Base” under Torsion with Bending

2019 ◽  
Vol 97 ◽  
pp. 04059 ◽  
Author(s):  
Alexey Dem’yanov ◽  
Vladymir Kolchunov ◽  
Igor Iakovenko ◽  
Anastasiya Kozarez
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Cross Sections ◽  
Concrete Beam ◽  
Equations Of State ◽  
Reinforced Concrete Beam ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Deformable Base ◽  
The Relationship

It is presented the formulation and solution of the load bearing capacity of statically indeterminable systems “reinforced concrete beam – deformable base” by spatial cross-sections under force and deformation effects. The solution of problem is currently practically absent in general form. It has been established the relationship between stresses and strains of compressed concrete and tensile reinforcement in the form of diagrams. The properties of the base model connections are described based on a variable rigidity coefficient. It is constructed a system of n equations in the form of the initial parameters method with using the modules of the force (strain) action vector. The equations of state are the dependences that establish the relationship between displacements which are acting on the beam with load. Constants of integration are determined by recurrent formulas. It makes possible to obtain the method of initial parameters in the expanded form and, consequently, the method of displacements for calculating statically indefinable systems. The values of the effort obtained could be used to determine the curvature and rigidity of the sections in this way. It is necessary not to set the vector modulusP, the deformation is set in any section (the module is considered as an unknown) during the problem is solving. This allows us to obtain an unambiguous solution even in the case when the dependence M–χ has a downward section, i.e one value of moment can correspond to two values of curvature.

Shear Failure of Patched Reinforced Concrete Beam without Web Reinforcements

2017 ◽  
Vol 737 ◽  
pp. 441-447 ◽  
Author(s):  
Stefanus Kristiawan ◽  
Agus Supriyadi ◽  
Senot Sangadji ◽  
Hapsara Brian Wicaksono
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Shear Failure ◽  
Unsaturated Polyester ◽  
Reinforced Concrete Beam ◽  
Concrete Cover ◽  
Patch Repair ◽  
Rc Beam ◽  
Diagonal Crack ◽  
The Web

Degradation of reinforced concrete (RC) element could lead to a reduction of its strength and serviceability. The degradation may be identified in the form of spalling of concrete cover. For the case of RC beam, spalling of concrete cover could occur at the web of the shear span due to corrosion of the web reinfocements. The shear strength of the damaged-RC beam possibly will become less conservative compared to the corresponding flexural strength with a risk of brittle failure. Patch repair could be a choice to recover the size and strength of the damaged-RC beam. This research investigates the shear failure of patched RC beam without web reinforcements with a particular interest to compare the shear failure behaviour of patched RC beam and normal RC beam. The patch repair material used in this research was unsaturated polyester resin (UPR) mortar. The results indicate that the initial diagonal cracks leading to shear failure of patched RC beam occur at a lower level of loading. However, the patched RC beam could carry a greater load before the diagonal crack propagates in length and width causing the beam to fail in shear.

scholarly journals A NONLINEAR FINITE ELEMENT ANALYSIS OF PRECAST INDUSTRIALISED BUILDING SYSTEM BEAM UNDER FLEXURAL TEST

2019 ◽  
Vol 81 (3) ◽  
Author(s):  
Chun-Chieh Yip ◽  
Jing-Ying Wong ◽  
Ka-Wai Hor
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Reinforced Concrete ◽  
Concrete Beam ◽  
Failure Modes ◽  
Reinforced Concrete Beam ◽  
Shear Cracks ◽  
Flexural Test ◽  
Element Analysis ◽  
Failure Behaviour

Software simulation enables design engineers to have a better picture of possible structural failure behaviour and determine the accuracy of a design before the actual structural component is fabricated. Finite element analysis is used to simulate the behaviour of the reinforced concrete beam under the flexural test. During the flexural test, results are recorded for both simulation and experimental tests. By comparing the results, beam displacement, crack patterns, and failure modes can be studied with better accuracy. The accuracy percentage for yield load and ultimate load between the two tests results were 94.12 % and 95.79 %, respectively, whereas the accuracy percentage for elastic gradient before the yielding stage was 81.08 %. The behaviour between simulation and laboratory models described is based on crack pattern and failure mode. The progression of von Mises (VM) stresses highlighted the critical areas of the reinforced concrete beam and correlation between the experimental specimen, in terms of flexural cracks, shear cracks, yielding of tension reinforcement, and the crushing of concrete due to compressive stress. This paper concludes that simulation can achieve a significant accuracy in terms of loads and failure behaviour compared to the experimental model.

scholarly journals Structural Behavior of Reinforced Self-Compacted Engineered Cementitious Composite Beams

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Bashar S. Mohammed ◽  
M. F. Nuruddin ◽  
Muhammad Aswin ◽  
Nursyuhada Mahamood ◽  
Hashem Al-Mattarneh
Keyword(s):  
Reinforced Concrete ◽  
Large Scale ◽  
Concrete Beam ◽  
Failure Modes ◽  
Reinforced Concrete Beam ◽  
Composite Beams ◽  
Experimental Results ◽  
Structural Behavior ◽  
Cementitious Composite ◽  
Engineered Cementitious Composite

Eight large-scale reinforced self-compacted engineered cementitious composite (R-SC-ECC) beams with different steel reinforcement ratios have been designed, prepared, cast, cured, and tested to failure at the age of 28 days. The experimental results have been compared with theoretical values predicted using EC2, RILEM, and VecTor2 models. Results show that failure modes in flexure and shear of R-SC-ECC beams are comparable to that of normal reinforced concrete beam. Nevertheless, contrary to VecTor2, models of EC2 and RILEM are not suitable for predicting reasonable ultimate moments for the beams, while results using VecTor2 model have successfully predicted the failure modes and load-deflection curves for all R-SC-ECC beams. It has been concluded that R-SC-ECC fall in the category of ductility class medium to high which gives advantages of using R-SC-ECC beams in regions susceptible to seismic activities.

scholarly journals THE EFFECTS OF INCLINED SHEAR REINFORCEMENT IN REINFORCED CONCRETE BEAM

2018 ◽  
Vol 30 (1) ◽  
Author(s):  
Nor Fazlin Zamri ◽  
Roslli Noor Mohamed ◽  
NurHafizah A. Khalid ◽  
Kang Yong Chiat
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Shear Failure ◽  
Reinforced Concrete Beam ◽  
Rc Beam ◽  
Rc Beams ◽  
Shear Reinforcement ◽  
Strain Behaviour ◽  
Different Types ◽  
Loading System

This paper presents the findings of an experimental data on the effects of inclined shearreinforcement in reinforced concrete (RC) beam. Two types of shear reinforcement of RC beamwere investigated, conventional stirrups (vertical links) and inclined shear reinforcement (45degrees of inclined shear reinforcement). The RC beam with conventional stirrups wasdesignated as a control specimen. The RC beams with different types of shear reinforcementwere tested for shear under four-point loading system. Comparisons were made between bothtypes of RC beam on load-deflection, load-steel strain, load-concrete strain behaviour and modeof failure. The theoretical and experimental were calculated by using conventional formulation inaccordance to EC 2 in order to verify the experimental results. From the results, it was observedthat the RC beam with 45 degree inclined shear reinforcement improved structural performancein shear by approximately 20% and thus prolong the shear failure behaviour as compared to theRC beam with vertical links.

scholarly journals Study on shear failure and repair method of reinforced concrete beam.

1985 ◽  
pp. 119-128
Author(s):  
Yoshio OZAKA ◽  
Motoyuki SUZUKI ◽  
Hiroki ISHIDA ◽  
Katsumi KATO
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Shear Failure ◽  
Reinforced Concrete Beam ◽  
Repair Method
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