Model of time-dependent and stress-dependent chloride penetration of concrete under sustained axial pressure in the marine environment

2018 ◽  
Vol 170 ◽  
pp. 207-216 ◽  
Author(s):  
Jun Xu ◽  
Fumin Li ◽  
Jie Zhao ◽  
Lang Huang
Keyword(s):  
Marine Environment ◽  
Chloride Penetration ◽  
Time Dependent ◽  
Axial Pressure ◽  
Stress Dependent

The Chloride Ion Penetration Model Coupled with Temperature and Moisture Transfer in Marine Environment

2012 ◽  
Vol 591-593 ◽  
pp. 2422-2427
Author(s):  
Juan Zhao
Keyword(s):  
Marine Environment ◽  
Moisture Transfer ◽  
Regional Climate ◽  
Chloride Ion ◽  
Chloride Penetration ◽  
Chloride Diffusion ◽  
Tidal Zone ◽  
Analog Simulation ◽  
Chloride Ion Penetration ◽  
Ion Penetration

Considering the complexity of the chloride ion penetration in concrete exposed to marine environment, an integrated chloride penetration model coupled with temperature and moisture transfer is proposed. The governing equations and parameters embody fully the cross-impacts among thermal conduction, moisture transfer and chloride ion penetration. Furthermore, the four exposure conditions are classified based on the different contact with the aggressive marine environment, and then the micro-climate condition on the concrete surface is investigated according to the regional climate characteristics, therefore, a comprehensive analog simulation to the chloride penetration process is proposed. To demonstrate that the proposed numerical model can correctly simulate the chloride diffusion in concrete, the integrated chloride diffusion model is applied in reproducing a real experiment, finally the model gives good agreement with the experimental profiles, and it is proved the tidal zone exposure results in a more severe attack on the reinforcement

scholarly journals FUNDAMENTAL STUDY ON EVALUATION FOR TIME-DEPENDENT CORROSION BEHAVIOR OF LONG STEEL MEMBERS IN MARINE ENVIRONMENT

2009 ◽  
Vol 65 (2) ◽  
pp. 440-453 ◽  
Author(s):  
Shigenobu KAINUMA ◽  
Naofumi HOSOMI ◽  
Atsushi GOTO ◽  
Yoshito ITOH
Keyword(s):  
Corrosion Behavior ◽  
Marine Environment ◽  
Time Dependent ◽  
Fundamental Study ◽  
Steel Members

scholarly journals Mechanical Behavior and Chloride Penetration of Precracked Reinforced Concrete Beams with Externally Bonded CFRP Exposed to Marine Environment

2016 ◽  
Vol 2016 ◽  
pp. 1-8
Author(s):  
Yan Xie ◽  
Kunhua Guan ◽  
Lei Zhan ◽  
Qichen Wang
Keyword(s):  
Reinforced Concrete ◽  
Marine Environment ◽  
Chloride Penetration ◽  
Reinforced Concrete Beams ◽  
Bending Test ◽  
Chloride Diffusion ◽  
Accelerated Ageing ◽  
Rc Beams ◽  
Cfrp Sheets ◽  
Externally Bonded

Cracked reinforced concrete (RC) beams can be repaired effectively by using externally bonded CFRP sheets. However, when the strengthened beams are subjected to marine environment, long-term performance will be affected by the material and the interface deterioration of concrete and CFRP. Therefore, to evaluate the service life of the strengthened beams, this study investigates the behavior of precracked RC beams strengthened with CFRP sheets exposed to marine environment. Accelerated ageing experiments were carried out by exposing specimens to cyclic wetting in sea water and drying in 40°C air for 3 months and 6 months, respectively. After the environment exposure, four-point bending test was conducted and then the diffusion of chlorides in the strengthened beams was analysed. The results show that the bonding behavior of the adhesive was weakened and the ductility of the strengthened beams was slightly reduced due to the marine environment. But there is no obvious strength difference between the strengthened beams suffered from marine environment for 3 months and 6 months. Besides, the precracks in the RC beams accelerated the chloride diffusion, while CFRP bonding reduced the chloride penetration. In addition, NEL method was employed to validate the effect of the cracks on chloride permeability. The results showed that the chloride diffusion coefficients increased with the depth of the cracks.

scholarly journals Evaluation Technique of Chloride Penetration Using Apparent Diffusion Coefficient and Neural Network Algorithm

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Yun-Yong Kim ◽  
Byung-Jae Lee ◽  
Seung-Jun Kwon
Keyword(s):  
Neural Network ◽  
Diffusion Coefficient ◽  
Apparent Diffusion Coefficient ◽  
Chloride Penetration ◽  
Time Dependent ◽  
Network Algorithm ◽  
Analysis Technique ◽  
Apparent Diffusion ◽  
Neural Network Algorithm

Diffusion coefficient from chloride migration test is currently used; however this cannot provide a conventional solution like total chloride contents since it depicts only ion migration velocity in electrical field. This paper proposes a simple analysis technique for chloride behavior using apparent diffusion coefficient from neural network algorithm with time-dependent diffusion phenomena. For this work, thirty mix proportions of high performance concrete are prepared and their diffusion coefficients are obtained after long term-NaCl submerged test. Considering time-dependent diffusion coefficient based on Fick’s 2nd Law and NNA (neural network algorithm), analysis technique for chloride penetration is proposed. The applicability of the proposed technique is verified through the results from accelerated test, long term submerged test, and field investigation results.

Unified Constitutive Modelling of Nonlinear Time-Dependent Materials

1989 ◽  
Vol 42 (11S) ◽  
pp. S78-S82
Author(s):  
P. G. Glockner ◽  
W. Szyszkowski
Keyword(s):  
Strain Softening ◽  
Strain Tensor ◽  
Damage Function ◽  
Constitutive Modelling ◽  
Constitutive Law ◽  
Time Dependent ◽  
Type Integral ◽  
Characteristic Features ◽  
Stress Dependent ◽  
Semi Empirical

A semi-empirical engineering constitutive law modelling in a unified and continuous manner the main characteristic features of time-dependent materials, including creep, strain softening, relaxation and recovery and tensile brittleness, is briefly reviewed. The model, which contains 13 parameters, is a hereditary single Volterra-type integral representation of material response with stress/strain nonlinearity assumed in the form of a power law, the strain tensor dependent on the entire stress history and the stress-anisotropy/brittleness feature handled by means of a tensile-stress dependent damage function. The capability/versatility of the model is illustrated by examples for several materials.

scholarly journals Limitations of sorptivity and water permeability for the estimation of the chloride penetration rate in concrete regarding the accomplishment of prescriptive design for durability in the marine environment

2018 ◽  
Vol 8 (3) ◽  
pp. 301-316
Author(s):  
Yury A Villagrán Zaccardi ◽  
María E Sosa ◽  
Ángel A Di Maio
Keyword(s):  
Marine Environment ◽  
Diffusion Rate ◽  
Penetration Rate ◽  
Chloride Penetration ◽  
Chloride Diffusion ◽  
Capillary Absorption ◽  
Chloride Ingress ◽  
Water Penetration ◽  
Conventional Concrete

This paper presents an analysis of experimental data from conventional concrete regarding sorptivity and penetrability under pressure comparing these parameters to chloride diffusion rate determined in the laboratory and in actual marine environment. Prescriptions for durability assurance of reinforced concrete structures is based on the qualitative characterization of transport properties. For the specific case of the marine environment, it is required to assess the resistance of concrete to chloride ingress. The results show the limitations of both parameters as prescriptive indexes, with capillary absorption rate showing some advantages over water penetration under pressure.

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