The Reinforced Concrete Durability and Rebar Erosion Monitoring

2012 ◽  
Vol 446-449 ◽  
pp. 3252-3258
Author(s):  
Jin Yang Zhang ◽  
De Mi Cui ◽  
Lie Min Lv ◽  
Zhi Yang
Keyword(s):  
Reinforced Concrete ◽  
Service Life ◽  
Protective Layer ◽  
Concrete Surface ◽  
Monitor System ◽  
Concrete Durability ◽  
Information Feedback ◽  
Starting Time ◽  
Cast Concrete

On the basis of the advantages of low construction cost, remarkable dynamics property, easy cast moulding and more controllable construction, the reinforced concrete construct are widely applied in buildings and main structures of constructions in China. However, the reinforced concrete is found more or less aging after many years’ utilization and erosion from the environment, which will lead to a hidden risk to affect its functions. After technical development for decades, the concrete can assure its durability under normal situation, yet the function would be deteriorated due to the erosion from the complex and harsh environment to make it hardly reach its designed service life. With the assist of CorroWatch erosion monitor system, the concrete structures’ erosion can kept watched on to obtain the depassivation development and information feedback of some key data dynamically and in long term so as to foresee precisely the erosion starting time. The newly cast concrete depassivation frontline is located on concrete surface and will tend to go through the protective layer and penetrate towards rebar as time goes on. Its structure service life can be enhanced with the re-designed durability in terms of the mentioned characters and do well the erosion proof measures.

Reinforced Concrete Durability in Marine Environments DURACON Project: Long-Term Exposure

CORROSION ◽  
10.5006/1893 ◽  
2016 ◽  
Vol 72 (6) ◽  
pp. 824-833 ◽  
Author(s):  
O. Troconis de Rincón ◽  
J.C. Montenegro ◽  
R. Vera ◽  
A.M. Carvajal ◽  
R.M. de Gutiérrez ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Concrete Durability ◽  
Marine Environments

Prediction of durability of structural concrete in aggressive exposures

2018 ◽  
Author(s):  
Сергей Леонович ◽  
Sergey Leonovich ◽  
Валентин Доркин ◽  
Valentin Dorkin ◽  
Оксана Чернякевич ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Service Life ◽  
Building Materials ◽  
Limit State ◽  
Concrete Structures ◽  
Life Cycles ◽  
Reinforced Concrete Structures ◽  
Concrete Durability ◽  
Concrete Carbonation ◽  
Corrosion Of Steel

The monograph is devoted to the prediction of the longevity of reinforced concrete structures, the destruction of which is associated with corrosion of steel reinforcement caused by chloride aggression or concrete carbonation. On the basis of a comprehensive analysis of models for calculating the service life of structures and experimental data, preference is given to the mathematical model Dura Crete. Life cycles for the main degradation processes in concrete and reinforcement, periods of initiation and propagation of corrosion are considered. Particular attention is paid to the influence of environmental factors and the quality of concrete on the kinetics of chloride penetration and movement of the carbonization front. Formulated limit state design reinforced concrete durability in chloride attacks and carbonation. The basic provisions of the method of calculating the durability of reinforced concrete structures, based on the use of the reliability coefficient for the service life. The practical assessment of service life of reinforced concrete elements taking into account stochastic processes in concrete and reinforcement is made. Verification of the model reliability is performed. For all those interested in the issues of building materials and processes occurring in them.

scholarly journals DEGRADATION DAMAGE OF REINFORCED CONCRETE FRAME IN LONG-TERM EXPLOITATION

2021 ◽  
Vol 9 (4) ◽  
pp. 11-15
Author(s):  
Mikhail Berlinov ◽  
Marina Belinova ◽  
Roman Korol ◽  
Aleksandr Tvorogov
Keyword(s):  
Reinforced Concrete ◽  
Service Life ◽  
Phenomenological Theory ◽  
Reinforced Concrete Frame ◽  
Term Operation ◽  
Concrete Frame ◽  
Aggressive Environment ◽  
Real Work ◽  
Combined Action

A method for calculating a reinforced concrete frame under rheological deformation conditions is proposed, taking into account degradation damage as a result of corrosion during long-term operation, reflecting their real work under the combined action of a load and an aggressive environment based on the modern phenomenological theory of deformation of an elastic-creeping body. The possibility of considering the processes of long-term deformation of reinforced concrete in conditions of long-term exploitation is shown. Analytical dependencies and a calculated example are given for the considered service life.

The Experimental Study on Fatigue Properties of CFRP Reinforced Concrete Beam

2011 ◽  
Vol 383-390 ◽  
pp. 3157-3161
Author(s):  
Zi Qi Li ◽  
Yan Yan Fan
Keyword(s):  
Experimental Study ◽  
Reinforced Concrete ◽  
Service Life ◽  
Concrete Beam ◽  
Concrete Structures ◽  
Reinforced Concrete Beam ◽  
Fatigue Performance ◽  
Fatigue Properties ◽  
Experimental Basis

Based on the research of CFRP reinforced concrete beam , this article indicates that CFRP can improve greatly the fatigue performance of damage concrete beam, prolong its service life , and provide the experimental basis for long-term fatigue properties of CFRP concrete structures.

scholarly journals Long-term Influence of Concrete Surface and Crack Orientation on Self-healing and Ingress in Cracks – Field Observations

2018 ◽  
Vol 58 (1) ◽  
pp. 1-16 ◽  
Author(s):  
Tobias Danner ◽  
Mette Rica Geiker
Keyword(s):  
Reinforced Concrete ◽  
Concrete Surface ◽  
Reinforced Concrete Structures ◽  
Chloride Ingress ◽  
Field Observations ◽  
Self Healing ◽  
Crack Orientation ◽  
Horizontal Orientation ◽  
The Impact

Abstract This paper presents results from investigations on the long-term influence of concrete surface and crack orientation on ingress in cracks. Five reinforced concrete structures from Norway exposed to either de-icing salts or seawater have been investigated. Concrete cores were taken with and without cracks from surfaces with vertical and horizontal orientation. Carbonation in cracks was found on all de-iced structures, and a crack on a completely horizontal surface appeared to facilitate chloride ingress. Ingress of substances from seawater was found in all cracks from marine exposure. However, the impact of cracks on chloride ingress was unclear. Horizontal cracks on vertical surfaces appeared to facilitate self-healing.

scholarly journals Reinforced Concrete under the Action of Carbonization and Chloride Aggression: a Probabilistic Model for Service Life Prediction

2019 ◽  
Vol 18 (4) ◽  
pp. 284-291 ◽  
Author(s):  
S. N. Leonovich ◽  
E. E. Shalyi ◽  
L. V. Kim
Keyword(s):  
Reinforced Concrete ◽  
Service Life ◽  
Life Prediction ◽  
Ph Value ◽  
Chloride Concentration ◽  
Protective Layer ◽  
Service Life Prediction ◽  
Simultaneous Action ◽  
Shelf Zone ◽  
Reinforcement Corrosion

Reinforcement corrosion of marine and coastal hydraulic structures due to chloride aggression and concrete carbonization leads to a sharp decrease in structure safety. The reinforcement is subjected to a depassivation process as soon as a chloride concentration on its surface exceeds a certain threshold concentration, or the pH value in a concrete protective layer is decreased to a threshold value due to carbonation. Electrochemical reactions are realized with formation of corrosion products due to penetration of oxygen up to reinforcement surface. This leads to cracking of the concrete protective layer and decrease in reinforcement cross-section. The paper proposes a method for predicting a complex degradation of reinforced concrete structures with due account of various mechanisms of corrosion wear that allows to develop efficient methods for improvement of structure durability and maintainability which are operated in the marine environment. A methodology for forecasting of reinforced concrete service life prediction has been developed under a combined effect of carbonization and chloride aggression while using finite-difference and probability models. The paper takes into account initiation periods of reinforcement corrosion and propagation periods for conditions of Sakhalin shelf zone. Field surveys of Kholmsk and Korsakov port facilities are presented in the paper. Carbonization front and chloride content have been estimated according to depth of the concrete protective layer. The paper proposes a model that allows to determine an average period prior to repair while taking into account rate of concrete protective layer degradation caused by simultaneous action of two corrosion processes: carbonization and chloride aggression.

Electro-Migration Corrosion Inhibitors for Chlorides Induced Corrosion in Reinforced Concrete

2013 ◽  
Vol 477-478 ◽  
pp. 1007-1013
Author(s):  
Xiao Dong Hu ◽  
Jun You Huang ◽  
Zhi Qing Li ◽  
Song Gan Weng
Keyword(s):  
Reinforced Concrete ◽  
Corrosion Inhibition ◽  
Corrosion Inhibitors ◽  
Corrosion Potential ◽  
Protective Layer ◽  
Galvanic Current ◽  
Concrete Deterioration ◽  
Current Weight

In connection with the reinforced concrete deterioration by chlorides, a new electro-migration corrosion inhibitors which can move to the surface of rebar covered by 100mm protective layer, was used. And through the test of macro galvanic current, weight lost and corrosion potential, the effect of corrosion inhibitors was studied. The result showed that, with the reasonable treatment, a stable, long-term effectiveness of corrosion inhibition could be obtained.

scholarly journals On Stochastic Approach to Evaluation of Service Life for Reinforced Concrete Constructional Elements and Structures during Concrete Carbonization

2020 ◽  
Vol 19 (3) ◽  
pp. 241-251
Author(s):  
S. N. Osipov ◽  
V. M. Chik
Keyword(s):  
Reinforced Concrete ◽  
Service Life ◽  
Concrete Structures ◽  
Calculated Data ◽  
Protective Layer ◽  
Stochastic Approach ◽  
Reinforced Concrete Structures ◽  
Reinforced Concrete Structure ◽  
Deterministic Models

The currently existing deterministic models for determination of structure service life do not take into account to the full extent variety of factors that have an effect on them and also stochastic characteristics of the used natural materials and conditions for manufacturing construction products, possible errors during the process of designing and construction etc. More trustworthy approach determining longevity and growth rate of destruction processes for structures in future periods can be obtained with the help of statistic methods that take into account a probabilistic essence of the process. The paper presents a possible approach of the probabilistic analysis on reinforced concrete structure service life while assessing rates of variation in depth growth of carbonization in a concrete protective layer on the basis of the existing experimental and calculated data pertaining to changes of the given index in reinforced concrete structures of various types. Variability of the existing approaches for determination of structure longevity as a whole has been shown firstly due to various number of basic vаriables used in calculations. Stochastic processing of the data on parameters of carbonization depth in the concrete protective layer has been carried out and this processing has made it possible to determine variation rates which allow to assess the presupposed service life of reinforced concrete structures having similar characteristics and being operated under analogous conditions. A definitive non-uniformity in statistic indices has been established that testifies about the necessity to increase accumulation of data on the investigated characteristics and to execute its processing more thoroughly. An expedience in usage of a concrete impermeability as a main factor determining its longevity has been established on the basis of statistical assessment of the existing data.

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