scholarly journals Distributed Fiber Optics Sensing and Coda Wave Interferometry Techniques for Damage Monitoring in Concrete Structures

Sensors ◽  
2019 ◽  
Vol 19 (2) ◽  
pp. 356 ◽  
Author(s):  
Antoine Bassil ◽  
Xin Wang ◽  
Xavier Chapeleau ◽  
Ernst Niederleithinger ◽  
Odile Abraham ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Fiber Optics ◽  
Asset Management ◽  
Crack Opening ◽  
Concrete Structures ◽  
Reinforced Concrete Beam ◽  
Coda Wave ◽  
Reinforced Concrete Structures ◽  
Detection And Localization ◽  
Coda Wave Interferometry

The assessment of Coda Wave Interferometry (CWI) and Distributed Fiber Optics Sensing (DFOS) techniques for the detection of damages in a laboratory size reinforced concrete beam is presented in this paper. The sensitivity of these two novel techniques to micro cracks is discussed and compared to standard traditional sensors. Moreover, the capacity of a DFOS technique to localize cracks and quantify crack openings is also assessed. The results show that the implementation of CWI and DFOS techniques allow the detection of early subtle changes in reinforced concrete structures until crack formation. With their ability to quantify the crack opening, following early detection and localization, DFOS techniques can achieve more effective monitoring of reinforced concrete structures. Contrary to discrete sensors, CWI and DFOS techniques cover larger areas and thus provide more efficient infrastructures asset management and maintenance operations throughout the lifetime of the structure.

scholarly journals Method of the Finite-Element Model Formation Containing the 3D Elements for Structural Calculations of the Reinforced Concrete Structures Considering the Crack Opening

2021 ◽  
Vol 23 (1) ◽  
pp. D15-D25
Author(s):  
Sergei N. Nazarenko ◽  
Galina A. Grudcina
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Crack Opening ◽  
Concrete Structures ◽  
Analytical Calculation ◽  
Element Model ◽  
Data File ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Structures ◽  
3D Elements

This article presents the 3D computational modeling method for reinforced concrete structures. An example of calculation of the reinforced concrete beam, using the Finite Element Method in SCAD++ following proposed algorithm, is given. Results comparison to the analytical calculation of the model with selected reinforcement is presented. For concrete, the 3D solid Finite Elements are used and the 3D beam elements for reinforcement. The model is formed using AutoCAD and AutoLISP, which creates a text data file in SCAD format for the description of model. In addition, computation of the 3D model of the crossbar with a crack is performed. Crack sizes are set in the stretched zone based on data from initial calculation. Graphic results obtained in SCAD++ are presented.

Experimental Evaluation of Corrosion Effect on Bond Between Steel and Concrete in Presence of Cyclic Action

2009 ◽  
Vol 417-418 ◽  
pp. 345-348 ◽  
Author(s):  
Luca Giordano ◽  
Giuseppe Mancini ◽  
Francesco Tondolo
Keyword(s):  
Reinforced Concrete ◽  
Cyclic Load ◽  
Crack Opening ◽  
Concrete Structures ◽  
Electrochemical Corrosion ◽  
Reinforced Concrete Structures ◽  
Reinforcing Bars ◽  
Cyclic Action ◽  
In Series ◽  
Ultimate Condition

Corrosion modifies the steel-concrete interface in reinforced concrete structures. The efficiency of the connection between the two materials is reduced and the structural behavior both in service and in ultimate condition is affected. Moreover in structures subjected to cyclic load, a simultaneous mechanical deterioration due to the load is present. In this work an experimental analysis on reinforced concrete structures under both cyclic load and corrosion of reinforcing bars is presented. Three couples of reinforced concrete ties are connected in series and subjected to the same stress variation in order to produce the cracking conditions and to activate the bond mechanism. However, while one of the two reinforced concrete ties is only subjected to cyclic load, the second one is also corroded using an accelerated electrochemical corrosion process. The simultaneous effect of the cyclic load and corrosion is evaluated monitoring the crack opening on the structures during the test and by means of visual inspection of the sample. The test results show the correlation between the mechanism of bond and the average level of stresses for an amplified stress range.

scholarly journals Optimization of reinforced concrete structures: importance of design detail level

2021 ◽  
Vol 263 ◽  
pp. 02002
Author(s):  
Ashot Tamrazyan ◽  
Anatoly Alekseytsev
Keyword(s):  
Reinforced Concrete ◽  
Cost Minimization ◽  
Concrete Structures ◽  
Reinforced Concrete Beam ◽  
Normal Operation ◽  
Design Solution ◽  
Reinforced Concrete Structures ◽  
Variable Parameters ◽  
Design Detail ◽  
The Cost

The study of the influence for design solution detailing on the cost of reinforced concrete structures during their optimization is carried out. A hypothesis is formulated on the final improvement of the target criterion with an increase in the number of variable parameters. Depending on this number, the concepts of three levels of detail are introduced, at which optimization can be carried out, and the degree of risk of failure of the structure is indicated for them. Using the example of finding a constructive solution for a reinforced concrete beam by the cost minimization criterion, the relationship of the cost change is shown when the number of independently variable parameters changes. The normal operation of the beam and the emergency action effects in the form of local damage to a single corner connection are taken into account. Genetic algorithms are used for the optimization.

scholarly journals Crack Detection of Reinforced Concrete Structures Based on BOFDA and FBG Sensors

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Qinghua Zhang ◽  
Ziming Xiong
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Crack Detection ◽  
Concrete Structures ◽  
Lower Surface ◽  
Reinforced Concrete Beam ◽  
Sensor Data ◽  
Reinforced Concrete Structures ◽  
Surface Cracks ◽  
Fbg Sensors

Reinforced concrete structural elements, as an important component of buildings and structures, require inspection for the purposes of crack detection which is an important part of structural health monitoring. Now existing crack detection methods usually use a single technology and can only detect internal or external cracks. In this paper, the authors propose a new sensing system combining BOFDA (Brillouin optical frequency-domain analysis) and FBG (fiber Bragg grating) technology, which are used to detect internal and surface cracks and their development in reinforced concrete structures, and an attempt is made to estimate the width of surface cracks. In these experiments, a special reinforced concrete beam structure was designed by the author for crack detection under load. Four continuous distributed optical fibers are fixed on the steel skeleton, which is located within the reinforced concrete beam. Three FBG sensors are fixed on the lower surface of the beam, near its centre. By analysing the sensor data, it can be found that the BOFDA-distributed fiber can be used to detect internal cracking before surface cracking, and the difference between scans can be used to judge the time of onset of internal cracking, but the relative error in position is about 5%, while the FBG sensor can detect the cracking time of microcracks on the lower surface in near-real-time and can be used to calculate the crack width. Through the experiment, it is found that if the combination of BOFDA and FBG technology is adopted, we can initially use the strain data obtained by multiple groups of BOFDA monitoring to predict the general location of the internal cracks, then to monitor the exact location of the surface cracks by FBG in the medium term, and to estimate the width of the final expansion of the cracks finally.

scholarly journals Experimental study of beams on yielding supports with thrust

2018 ◽  
Vol 143 ◽  
pp. 01016
Author(s):  
Oleg Kumpyak ◽  
Zaur Galyautdinov ◽  
Daud Galyautdinov
Keyword(s):  
Reinforced Concrete ◽  
Crack Resistance ◽  
Dynamic Loading ◽  
Experimental Studies ◽  
Concrete Structures ◽  
Horizontal Displacement ◽  
Positive Outcome ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Structures ◽  
Short Term

The design of reinforced concrete structures which are subjected to static and intensive dynamic loading requires taking into account the occurrence of thrust reaction resulting in significant increase in strength and crack resistance. Application of yielding supports for the purpose of increasing the energy capacity of structures shall also be considered. The present research aims to define feasibility of yielding supports application in thrust structures. The paper presents the outcomes of experimental studies of reinforced concrete beam structures on yielding supports subjected to thrust under static and short-term dynamic loading. The influence of thrust on the strength, deformation property and crack resistance of reinforced concrete structures under static and short-term dynamic loading was investigated. The combined use of yielding supports and the restriction of horizontal displacement of the support contour were also considered in the study. Research results testify on the positive outcome when yielding supports are applied in the structures subjected to thrust.

THE INFLUENCE OF BASALT-COMPOSITE PRESTRESSED REINFORCEMENT ON THE OPERATION OF LOW-REINFORCED CONCRETE STRUCTURES WITH INTERBLOCK CONSTRUCTION JOINTS

2020 ◽  
pp. 50-59
Author(s):  
O.D. RUBIN ◽  
◽  
S.E. LISICHKIN ◽  
O.V. ZYUZINA
Keyword(s):  
Reinforced Concrete ◽  
Experimental Studies ◽  
Concrete Structures ◽  
Bending Moment ◽  
Reinforced Concrete Beam ◽  
Hydraulic Structures ◽  
Reinforced Concrete Structures ◽  
Beam Type ◽  
Construction Joints ◽  
Composite Reinforcement

It is proposed to use prestressed basalt composite reinforcement to strengthen reinforced concrete structures of hydraulic structures. In order to substantiate technical reinforcement of reinforced concrete structures of hydraulic structures with prestressed basalt composite inforcement, experimental studies were carried out. For experimental studies, reinforced concrete beam-type structures with vertical interblock construction joints were adopted.The results of experimental studies of reinforced concrete models of beam type with interblock joints reinforced with prestressed basalt composite reinforcement by the method of tension “on concrete”are presented. The models are tested for bending moment and transverse force. A special character of cracking is noted; full restoration of the bearing capacity of reinforced concrete structures, weakened by interblock construction joints, was recorded due to the reinforcement of prestressed basalt composite reinforcement.

A fiber optics enriched Digital Twin for assessment of reinforced concrete structures

2021 ◽  
Author(s):  
Carlos G. Berrocal ◽  
Ignasi Fernandez ◽  
Rasmus Rempling
Keyword(s):  
Reinforced Concrete ◽  
Fiber Optics ◽  
Asset Management ◽  
Web Application ◽  
Large Scale ◽  
Management Strategies ◽  
Reinforced Concrete Beam ◽  
Structural Condition ◽  
Ongoing Research ◽  
Digital Twin

<p>This paper presents the results of <i>SensIT</i>, an ongoing research initiative at Chalmers University of Technology aimed at developing a digital twin concept to improve the asset management strategies of reinforced concrete infrastructure. The developed concept relies on data collected from distributed optical fiber sensors (DOFS), which are then analysed to extract relevant features, such as deflections and crack widths, that can be used as indicators of the structural performance. Thereafter, intuitive contour plots are generated to deliver critical information about the element’s structural condition in a clear and straightforward manner. Last, both raw and analysed data are integrated into a collaborative web application where information can be readily accessed, and results can be visualized directly onto a 3D model of the element. The concept has been tested on a large-scale reinforced concrete beam subjected to flexural loading in laboratory conditions.</p>

scholarly journals Seismic Behaviour of Exterior Reinforced Concrete Beam-Column Joints in High Performance Concrete Using Metakaolin and Partial Replacement with Quarry Dust

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
G. R. Vijay Shankar ◽  
D. Suji
Keyword(s):  
Reinforced Concrete ◽  
Cyclic Loading ◽  
High Performance ◽  
Concrete Beam ◽  
High Performance Concrete ◽  
Concrete Structures ◽  
Reinforced Concrete Beam ◽  
Partial Replacement ◽  
Displacement Curve ◽  
Reinforced Concrete Structures

Recent earthquakes have demonstrated that most of the reinforced concrete structures were severely damaged; the beam-column joints, being the lateral and vertical load resisting members in reinforced concrete structures, are particularly vulnerable to failures during earthquakes. The existing reinforced concrete beam-column joints are not designed as per code IS13920:1993. Investigation of high performance concrete (HPC) joints with conventional concrete (CC) joints (exterior beam-column) was performed by comparing various reinforcement detailing schemes. Ten specimens were considered in this investigation and the results were compared: four specimens with CC (with and without seismic detailing), four specimens with HPC (with and without seismic detailing), and two specimens with HPC at confinement joint. The test was conducted for lateral load displacement, hysteresis loop, load ratio, percent of initial stiffness versus displacement curve, total energy dissipation, strain in beam main bars, and crack pattern. The results reveal that HPC with seismic detailing will be better compared with other reinforcements details under cyclic loading and reverse cyclic loading.

scholarly journals Nonlinear calculation of reinforced concrete structures to the impact of the air shock wave

Vestnik MGSU ◽  
2019 ◽  
pp. 33-45 ◽  
Author(s):  
Anton Y. Savenkov ◽  
Oleg V. Mkrtychev
Keyword(s):  
Numerical Simulation ◽  
Shock Wave ◽  
Reinforced Concrete ◽  
Nonlinear Dynamic ◽  
Software Package ◽  
Crack Opening ◽  
Concrete Structures ◽  
Reinforced Concrete Structures ◽  
Advantages And Disadvantages ◽  
The Impact

Introduction. Researched methods of accounting for the nonlinear operation of reinforced concrete structures on the example of an industrial structure, when exposed to an air shock wave using modern software systems based on the finite element method. The calculation of reinforced concrete construction to the impact of an air shock wave, if no increased requirements for tightness are presented to it, in accordance with current regulatory documents, must be carried out taking into account the elastic-plastic work, crack opening in the stretched zone of concrete and plastic deformations of reinforcement are allowed. Reviewed by new coupling approach to determining the dynamic loads of a shock wave, implemented in the LS-DYNA software package, which allows to take into account the effects of a long-range explosion and wave-wrapping around a structure. Materials and methods. The study of the stress-strain state of the structures was carried out using numerical simulation. For the nonlinear equivalent-static method, a step-by-step calculation algorithm is used, with gradual accumulation and distribution of stresses, implemented in the LIRA-SAPR software package. For the nonlinear dynamic method, the Lagrangian-Eulerian formulation is used using the methods of gas dynamics in the LS-DYNA software package. Results. As a result of numerical simulation, the following was done analysis of existing methods of nonlinear calculations; analysis of the existing loads during the flow of shock waves around the structure; analysis of the forces and movements in the bearing elements, as well as pictures of the destruction of concrete and reinforcement. Conclusions. According to the results of the comparison of the two approaches, conclusions are drawn about the advantages and disadvantages of the methods. Advantages of nonlinear dynamic calculation methods are noted compared to the equivalent-static ones. Use of the combined approach to the description of the shock wave front gives a reduction in time and allows us to describe the interaction of the wave with the structure with sufficient accuracy. The findings indicate the relevance of the study and provide an opportunity to move to more reasonable computational models.

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