scholarly journals A Multichannel Strain Measurement Technique for Nanomodified Smart Cement-Based Sensors in Reinforced Concrete Structures

Sensors ◽  
2021 ◽  
Vol 21 (16) ◽  
pp. 5633
Author(s):  
Andrea Meoni ◽  
Antonella D’Alessandro ◽  
Massimo Mancinelli ◽  
Filippo Ubertini
Keyword(s):  
Reinforced Concrete ◽  
Measurement Technique ◽  
Strain Measurement ◽  
Concrete Structures ◽  
Strain Sensing ◽  
Rc Structures ◽  
Multichannel Measurement ◽  
Sensing Technology ◽  
Technological Improvements ◽  
Detection And Localization

Nanomodified smart cement-based sensors are an emerging self-sensing technology for the structural health monitoring (SHM) of reinforced concrete (RC) structures. To date, several literature works demonstrated their strain-sensing capabilities, which make them suited for damage detection and localization. Despite the most recent technological improvements, a tailored measurement technique allowing feasible field implementations of smart cement-based sensors to concrete structures is still missing. In this regard, this paper proposes a multichannel measurement technique for retrieving strains from smart cement-based sensors embedded in RC structures using a distributed biphasic input. The experiments performed for its validation include the investigation on an RC beam with seven embedded sensors subjected to different types of static loading and a long-term monitoring application on an RC plate. Results demonstrate that the proposed technique is effective for retrieving time-stable simultaneous strain measurements from smart cement-based sensors, as well as for aiding the identification of the changes in their electrical outputs due to the influence of environmental effects variable over time. Accordingly, the proposed multichannel strain measurement technique represents a promising approach for performing feasible field implementations of smart cement-based sensors to concrete structures.

Damage of Reinforced Concrete Structures due to Steel Corrosion

2015 ◽  
Vol 1111 ◽  
pp. 187-192
Author(s):  
Corina Sosdean ◽  
Liviu Marsavina ◽  
Geert de Schutter
Keyword(s):  
Reinforced Concrete ◽  
Building Materials ◽  
Structural Integrity ◽  
Colorimetric Method ◽  
Concrete Structures ◽  
Steel Corrosion ◽  
Degradation Process ◽  
Reinforced Concrete Structures ◽  
Chloride Ingress ◽  
Rc Structures

Reinforced concrete (RC) became one of the most widely used modern building materials. In the last decades a great interest has been shown in studying reinforcement corrosion as it became one of the main factors of degradation and loss of structural integrity of RC structures. The degradation process is accelerated in the case of RC structures situated in aggressive environments like marine environments or subjected to de-icing salts. In this paper it is shown how steel corrosion of the embedded rebars occurs and how this affects the service life of reinforced concrete structures. Also, an experimental study regarding the combined effect of carbonation and chloride ingress was realized. Samples with and without rebars were drilled from a RC slab which was stored in the laboratory for two years. Non-steady state migration tests were realized in order to determine the chloride profile, while the carbonation depth was measured using the colorimetric method based on phenolphthalein spraying. It was concluded that carbonation has a significant effect on chloride ingress, increasing it.

scholarly journals Effects of Tension Reinforcement Ratio on Ductility of Mid-Rise Reinforced Concrete Structures

2018 ◽  
Vol 1 (1) ◽  
pp. 702-708
Author(s):  
Onur Onat ◽  
Burak Yön
Keyword(s):  
Reinforced Concrete ◽  
Failure Mode ◽  
Concrete Structures ◽  
Reinforcement Ratio ◽  
Reinforced Concrete Structures ◽  
Rc Structures ◽  
Beam Elements ◽  
First Case ◽  
Rc Structure ◽  
Determine Effect

Failure mode of reinforced concrete (RC) structures are classified according to tension reinforcement ratio of beam elements. To determine effect of tension reinforcement ratio on performance of RC structure, two planar RC structure were selected. One of them is 5 stories other of them is 7 stories. Two different concrete class, C20 and C25, were considered for analysis. Three tension reinforcement combinations were considered, three different tension reinforcement ratios were used. First case is the ratio of the tension reinforcement is lower than that of the compression reinforcement, second case is the ratio of the tension reinforcement is equal to the ratio of the compression reinforcement and third case is the ratio of the tensile reinforcement is higher than the compression reinforcement.

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.

Residual Service Life Prediction of Offshore Concrete Structures With Chloride-Induced Damage: The State of the Art

2013 ◽  
Author(s):  
S. M. S. M. K. Samarakoon ◽  
R. M. Chandima Ratnayake
Keyword(s):  
Reinforced Concrete ◽  
Service Life ◽  
Prediction Models ◽  
Laboratory Data ◽  
Concrete Structures ◽  
Residual Service Life ◽  
Reinforcement Corrosion ◽  
Rc Structures ◽  
Maintenance And Repair ◽  
Remaining Service Life

Offshore oil and gas (O&G) production and process facilities (P&PFs) consist of concrete components and structures with steel reinforcement and pre-stressing tendons. They are vulnerable to deterioration due to chloride-induced damage from being exposed to the severe marine environment. The aforementioned deterioration creates significant challenges to the life extension analysis presently required for P&PFs located in the North Sea. Currently, maintenance work has been carried out via in-service inspection and condition monitoring to assure the structural integrity at a pre-specified level of P&PFs. In this context, the knowledge from existing models forms a basis for making quantitative predictions of the remaining service life of structures and components made of concrete. The service life of reinforced concrete structures in relation to reinforcement corrosion is usually modeled considering the initiation period and the corrosion propagation period. The formation of optimal proactive maintenance and repair strategies for corrosion-damaged reinforced concrete (RC) structures is highly dependent on the results of prediction models. The combination of both field (i.e. inspection) and laboratory data with numerical modeling helps the formulation of models for the prediction of the time to pre-defined limit states or to estimate the time for carrying out necessary maintenance and repair. This manuscript provides a review of the available methods for predicting the remaining service life of RC structures in relation to reinforcement corrosion. It also highlights suitable methods for predicting the remaining service life of offshore ageing concrete structures in a severe corrosive environment.

A Novel TDR-Based Coaxial Cable Sensor for Crack/Strain Sensing in Reinforced Concrete Structures

2009 ◽  
Vol 58 (8) ◽  
pp. 2714-2725 ◽  
Author(s):  
Shishuang Sun ◽  
D.J. Pommerenke ◽  
J.L. Drewniak ◽  
Genda Chen ◽  
Liang Xue ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Concrete Structures ◽  
Coaxial Cable ◽  
Reinforced Concrete Structures ◽  
Strain Sensing

scholarly journals Reinforcement corrosion in reinforced concrete Structures: Classification and overview

2021 ◽  
Vol 2 (1) ◽  
pp. 19-24
Author(s):  
Nour Eldeen Abo Nassar
Keyword(s):  
Reinforced Concrete ◽  
Concrete Structures ◽  
Control Measures ◽  
Reinforced Concrete Structures ◽  
Reinforcement Corrosion ◽  
Early Failure ◽  
Comprehensive Review ◽  
Rc Structures ◽  
Entire Structure ◽  
Steel Bars

Reinforced concrete (RC) structures have the ability to be extremely durable and able to withstand a diversity of different environmental cases. However, failure in these structures still happens due to precocious reinforcement erosion. If steel reinforcement corrodes in concrete structures, this leads to a decrease in the lifetime and durability of these structures, which cause early failure of the structures, costing significantly to inspect and maintain the deteriorating structures. Then, monitoring of reinforcement corrosion is of great importance to prevent early failure of structures. Structures corrosion can be decreased through correct monitoring and taking appropriate control measures in the appropriate period of time. When steel bars corrode, the formation of rust causes the concrete to be separated from the steel and then thereafter. In case this issue is not addressed, it may influence the entire structure. This paper attempts to present a comprehensive review of corrosion of rebar in RC structures, its mechanisms, monitoring and prevention.

scholarly journals Autonomous Corrosion Assessment of Reinforced Concrete Structures: Feasibility Study

Sensors ◽  
2020 ◽  
Vol 20 (23) ◽  
pp. 6825
Author(s):  
Woubishet Zewdu Taffese ◽  
Ethiopia Nigussie
Keyword(s):  
Reinforced Concrete ◽  
Feasibility Study ◽  
Concrete Structures ◽  
Chloride Ion ◽  
High Sensitivity ◽  
Reinforced Concrete Structures ◽  
Corrosion Condition ◽  
Rc Structures ◽  
Corrosion Assessment ◽  
Use Of Internet

In this work, technological feasibility of autonomous corrosion assessment of reinforced concrete structures is studied. Corrosion of reinforcement bars (rebar), induced by carbonation or chloride penetration, is one of the leading causes for deterioration of concrete structures throughout the globe. Continuous nondestructive in-service monitoring of carbonation through pH and chloride ion (Cl−) concentration in concrete is indispensable for early detection of corrosion and making appropriate decisions, which ultimately make the lifecycle management of RC structures optimal from resources and safety perspectives. Critical state-of-the-art review of pH and Cl− sensors revealed that the majority of the sensors have high sensitivity, reliability, and stability in concrete environment, though the experiments were carried out for relatively short periods. Among the reviewed works, only three attempted to monitor Cl− wirelessly, albeit over a very short range. As part of the feasibility study, this work recommends the use of internet of things (IoT) and machine learning for autonomous corrosion condition assessment of RC structures.

scholarly journals Crack Detection of Reinforced Concrete Member Using Rayleigh-Based Distributed Optic Fiber Strain Sensing System

2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Tingjin Liu ◽  
Honghao Huang ◽  
Yubing Yang
Keyword(s):  
Reinforced Concrete ◽  
Optical Fiber ◽  
Optical Fibers ◽  
Crack Detection ◽  
Concrete Surface ◽  
Strain Sensing ◽  
Rc Structures ◽  
Strain Measurements ◽  
Space Resolution ◽  
Sensing System

Early detection of crack is critical for the maintenance of reinforced concrete (RC) structures. In this study, a distributed optical fiber (DOF) sensing system with Rayleigh Optical Frequency Domain Reflectometry (OFDR) technique was deployed to a member of RC structure in a full-scale laboratory experiment, which was subjected to a monotonic lateral load. With the aid of a high space resolution (up to 1 mm) and measurement accuracy (±1 micro strain) interrogator (OSI-S by Semicon), continuous strain measurements inside of the RC member are elaborately implemented. The result of crack detection by the analysis of the measured tensile strain profiles is in excellent agreement with the visually observable cracks mapped during the test. This confirms the ability of the optical fiber inside of RC members to capture cracks on concrete surface. Moreover, the recognition of crack orientation and depth is accomplished by comparing strain measurements of optical fibers installed at multiple locations.

scholarly journals Collapse rates of reinforced concrete structures during large magnitude earthquakes: case study for Romania

2021 ◽  
Vol 3 (5) ◽  
Author(s):  
Florin Pavel
Keyword(s):  
Reinforced Concrete ◽  
Seismic Event ◽  
Concrete Structures ◽  
Reinforced Concrete Structures ◽  
Large Magnitude ◽  
Rc Structures ◽  
High Rise ◽  
The Moment ◽  
Water Tanks

AbstractThis case study focuses on the evaluation of the collapse rates of various types of reinforced concrete structures (residential and industrial) as observed from the data collected in Romania after the Mw 7.4 Vrancea earthquake of March 4, 1977. The results of the analyses show that the largest collapse rates were attributed to elevated reinforced concrete silos and water tanks. Moreover, the majority of the collapsed elevated reinforced concrete water tanks were full at the moment of the seismic event. Very small collapse rates were observed for high-rise residential RC structures and for the multi-storey industrial RC structures.

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