scholarly journals Lumped damage mechanics as a diagnosis tool of reinforced concrete structures in service: case studies of a former bridge arch and a balcony slab

2021 ◽  
Vol 15 (58) ◽  
pp. 21-32
Author(s):  
Rafael Cunha ◽  
Camila Vieira ◽  
David Amorim
Keyword(s):  
Reinforced Concrete ◽  
Case Studies ◽  
Damage Mechanics ◽  
Low Cost ◽  
Concrete Structures ◽  
Structural Condition ◽  
Numerical Analyses ◽  
Engineering Practice ◽  
Reinforced Concrete Structures ◽  
Diagnosis Tool

Reinforced concrete structures may need repair in order to ensure the designed durability. Such necessity vary in cause and effect, but the structural diagnosis serves as the basis for adopting intervention measures. The assessment of the structural condition usually is made in loco, but sometimes numerical analyses are required as a low cost and effective preliminary diagnosis. In general, numerical analyses use hundreds or thousands of finite elements and nonlinear theories that are not often used in engineering practice. As an alternative, lumped damage mechanics (LDM) uses key concepts of classic fracture and damage mechanics in plastic hinges throughout well-known quantities such as ultimate moment and cracking moment. Such theory describes the concrete cracking by a damage variable, which can be used as a diagnosis criterion. Therefore, this paper presents LDM as a diagnosis tool to analyse actual structures. The case studies presented in this paper are a former bridge arch tested in China and a balcony that collapsed in Brazil. The results show that LDM numerical response of those structures are quite close to laboratory observations (former bridge arch) and in loco measurements (balcony).

scholarly journals Development of low cost packaged fibre optic sensors for use in reinforced concrete structures

Measurement ◽  
2019 ◽  
Vol 135 ◽  
pp. 617-624 ◽  
Author(s):  
Richard H. Scott ◽  
Sanjay Chikermane ◽  
Miodrag Vidakovic ◽  
Brett McKinley ◽  
Tong Sun ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Low Cost ◽  
Concrete Structures ◽  
Reinforced Concrete Structures ◽  
Fibre Optic

Monitoring carbon steel behavior under biotic and abiotic conditions

2015 ◽  
Vol 1768 ◽  
Author(s):  
E.J. León ◽  
D.A. Koleva ◽  
H.M. Jonkers ◽  
J.M.C. Mol ◽  
H. Terryn ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Carbon Steel ◽  
Common Knowledge ◽  
Concrete Structures ◽  
Steel Corrosion ◽  
Engineering Practice ◽  
Reinforced Concrete Structures ◽  
Initial Surface ◽  
Abiotic Conditions ◽  
Simulated Environment

ABSTRACTDeterioration of concrete structures, together with corrosion of reinforcing steel due to the action of microorganisms, is known as Microbiologically Induced Corrosion of Concrete (MICC). The activity of microorganisms can initiate and further accelerate both steel corrosion and cement-based matrix degradation in reinforced concrete structures. The mechanism is related to initial surface colonization and further bio-products (and aggressive substance respectively) penetration into the bulk concrete matrix, reaching the reinforcement level. Common knowledge is that bio-deterioration-related infrastructure degradation, maintenance and repair have a significant economic impact worldwide. However, due to the complexity of all related mechanisms, a durable and feasible solution is still to be achieved for the engineering practice. This paper briefly points out main bio-degradation related mechanisms for concrete, steel and reinforced concrete structures and presents results on the electrochemical response of carbon steel in simulated environment under biotic and abiotic conditions.

scholarly journals Analysis of reinforced concrete structures through the ultrasonic pulse velocity: technological parameters involved

2017 ◽  
Vol 10 (2) ◽  
pp. 358-385 ◽  
Author(s):  
D.S. ADAMATTI ◽  
A. LORENZI ◽  
J. A. CHIES ◽  
L.C.P. SILVA FILHO
Keyword(s):  
Reinforced Concrete ◽  
Low Cost ◽  
Concrete Structures ◽  
Ultrasonic Pulse Velocity ◽  
Correct Choice ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Reinforced Concrete Structures ◽  
Technological Parameters ◽  
Surface Mapping

Abstract The application of Nondestructive Testing methods (NDT) may be an interesting strategy to monitor the condition state of reinforced concrete structures, especially when there are problems related to mixing, conveying or placing the concrete. Among the NDT methods, the Ultrasonic Pulse Velocity (UPV) has been one of the most used in various fields of civil engineering, due to the ease of operation, low cost, test velocity and low level of damage to the surface analyzed. This work aims to study the influence of certain technological variables in the results obtained through UPV tests. With this aim two large blocks were cast at the laboratory, with dimensions close to real concrete elements. One of the elements was reinforcement with steel meshes on both sides while the other was cast without reinforcement. Inside these elements objects were introduced to reproduce internal concrete flaws. To facilitate the analysis the results were represented by means of a surface mapping image technique and were also subjected to statistical analysis. Through the study it was demonstrated that the correct choice of test parameters is crucial to obtain a right interpretation of UPV results from real structures.

Damage mechanics applied to the modelling of corroded reinforced concrete structures

2010 ◽  
Vol 14 (6-7) ◽  
pp. 869-890 ◽  
Author(s):  
Frédéric Ragueneau ◽  
Benjamin Richard ◽  
Christian Crémona ◽  
Yves Berthaud
Keyword(s):  
Reinforced Concrete ◽  
Damage Mechanics ◽  
Concrete Structures ◽  
Reinforced Concrete Structures

Reliability of Existing Concrete Structures Determined with Physical Models - Carbonation Induced Corrosion

2017 ◽  
Vol 259 ◽  
pp. 255-260 ◽  
Author(s):  
Ivan Zambon ◽  
Anja Vidović ◽  
Alfred Strauss
Keyword(s):  
Reinforced Concrete ◽  
Prediction Models ◽  
Limit State ◽  
Concrete Structures ◽  
Structural Condition ◽  
Empirical Models ◽  
Physical Models ◽  
Reinforced Concrete Structures ◽  
Material Parameter Identification ◽  
Reliability Indices

The main goal of transportation infrastructure management is to optimize the use of infrastructure in the most beneficiary way while respecting the predefined requirements. One of the crucial parts in management strategy is the prediction of behaviour of vital transportation elements. Used prediction models should accurately describe the process of degradation and allow forecasting of structural condition by considering environment, usage and maintenance actions. Deterioration models can be divided into mathematical (statistical), physical and empirical models. Statistical models are based on data that describe condition of structure, such as for example condition rating. Physical models describe damage-causing processes and empirical models are experience based. The focus of this paper is to present the physical model of carbonation in assessment of performance of existing reinforced concrete structures in transportation networks. Assessment is done through determining the probability of limit state of depassivation. In order to determine the carbonation without testing, a special attention has to be given to environmental and material parameter identification. Herein, the identification takes into account weather specifics and construction practice in Austria. Finally, the reliability of existing reinforced concrete structures for combination of different exposure classes and material characteristics is analysed. Based on the analysis of reliability, the carbonation nomogram for engineering use is presented, showing the reliability indices β for the service life of 50 years.

Wireless low-cost corrosion sensors for reinforced concrete structures

2005 ◽  
Author(s):  
Nathan P. Dickerson ◽  
Jarkko T. Simonen ◽  
Matthew M. Ardringa ◽  
Sharon L. Wood ◽  
Dean P. Neikirk
Keyword(s):  
Reinforced Concrete ◽  
Low Cost ◽  
Concrete Structures ◽  
Reinforced Concrete Structures

scholarly journals Simplified damage models applied in the numerical analysis of reinforced concrete structures

2012 ◽  
Vol 5 (1) ◽  
pp. 26-37 ◽  
Author(s):  
J. J. C. Pituba ◽  
M. M. S. Lacerda
Keyword(s):  
Reinforced Concrete ◽  
Structural Engineering ◽  
Damage Model ◽  
Concrete Structures ◽  
Numerical Analyses ◽  
Anisotropic Damage ◽  
Reinforced Concrete Structures ◽  
Damage Models ◽  
Tension And Compression ◽  
Elastic Responses

This work presents one and two-dimensional numerical analyses using isotropic and anisotropic damage models for the concrete in order to discuss the advantages of these modeling. Initially, it is shortly described the damage model proposed by Mazars. This constitutive model assumes the concrete as isotropic and elastic material, where locally the damage is due to extensions. On the other hand, the damage model proposed by Pituba, the material is assumed as initial elastic isotropic medium presenting anisotropy, plastic strains and bimodular response (distinct elastic responses whether tension or compression stress states prevail) induced by the damage. To take into account for bimodularity two damage tensors governing the rigidity in tension and compression regimes, respectively, are introduced. Damage activation is expressed by two criteria indicating the initial and further evolution of damage. Soon after, the models are used in numerical analyses of the mechanical behavior of reinforced concrete structures. Accordingly with comparison of the obtained responses, considerations about the application of the isotropic and anisotropic damage models are presented for 1D and 2D reinforced concrete structures modeling as well as the potentialities of the simplified versions of damage models applied in situations of structural engineering.

Application of Polymer-Mortar Composites as a Sustainable Building Material

2015 ◽  
Vol 650 ◽  
pp. 21-28 ◽  
Author(s):  
A.S. Benosman ◽  
Y. Senhadji ◽  
M. Mouli
Keyword(s):  
Energy Efficiency ◽  
Reinforced Concrete ◽  
Composite Materials ◽  
Tap Water ◽  
Low Cost ◽  
Concrete Structures ◽  
Sound Intensity ◽  
Reinforced Concrete Structures ◽  
Destructive Testing ◽  
Polymer Mortar

In a number of countries, important research projects are nowadays carried out and are mainly devoted to developing original approaches to sustainability in order to improve the lifetime of reinforced concrete structures. This paper describes an innovative use of plastic bottle waste as cement-substitution within composite materials for preventing chemical attacks, energy efficiency in buildings or repairing various reinforced concrete structures. So, experiments were accomplished on polymer-mortar composite materials where the cement was partially replaced by various volume fractions of waste polyethylene terephthalate (PET) particles (0%, 6%, 12% and 17%). The specimens were tested by destructive and non-destructive testing and for chemical resistance to acid solutions at different concentrations. From this study, it was found that the PET-modified mortars exposed to aggressive environments showed better resistance to chemical attack than unmodified one without substantially affecting the mechanical strength in tap water and UPV values decrease as the proportion of PET waste in the mix increases. The addition of PET to the modified mortars, means reducing the penetration of aggressive agents. The formations which appear such as different calcium salts were determined by TG/dTG analysis. So, these composite materials are often used as low-cost materials for energy efficiency in buildings, preventing chemical attacks or repairing various reinforced concrete structures exposed to aggressive environments where high resistance to acid is required and to both reduce sound intensity and dampen vibrations.

A low-cost version of electro-mechanical impedance technique for damage detection in reinforced concrete structures using multiple piezo configurations

2016 ◽  
Vol 20 (8) ◽  
pp. 1247-1254 ◽  
Author(s):  
Naveet Kaur ◽  
Lingfang Li ◽  
Suresh Bhalla ◽  
Yong Xia
Keyword(s):  
Reinforced Concrete ◽  
Health Monitoring ◽  
Low Cost ◽  
Concrete Structures ◽  
Mechanical Impedance ◽  
Metal Wire ◽  
Reinforced Concrete Structures ◽  
Experimental Scheme ◽  
Impedance Technique ◽  
Lcr Meter

The electro-mechanical impedance technique has developed rapidly during the past few decades as a reliable health monitoring component of civil structures. However, the high cost of impedance analyzer/LCR meter conventionally used for data acquisition in the electro-mechanical impedance technique restricts its wide use in real applications. This article provides a comprehensive study of exploring the low-cost electro-mechanical impedance technique for health monitoring of concrete under destructive testing using multiple piezo configurations. The experimental scheme ensures separate acquisition of both the real and the imaginary components of the electro-mechanical impedance signature for detailed analysis, a feature not available in some previous low-cost adaptations. The piezo configurations covered here for comparison are the surface-bonded piezo configuration, the embedded piezo configuration, and the metal wire piezo configuration. The repeatability of the proposed low-cost electro-mechanical impedance technique is checked and the results are compared with the traditional counterpart utilizing conventional LCR meter. The two electro-mechanical impedance approaches show similar trends of the conductance signature for all configurations. In particular, the metal wire piezo configuration can be adopted as an excellent alternative in practice for reinforced concrete structures when the direct surface bonding is not feasible. Overall, the low-cost version of the electro-mechanical impedance technique is effective to detect the presence of the damage.

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