Decreased Corrosion Initiation Time of Steel in Concrete due to Reinforcing Bar Obstruction of Diffusional Flow

2002 ◽  
Vol 99 (1) ◽  
Keyword(s):  
Initiation Time ◽  
Reinforcing Bar ◽  
Corrosion Initiation ◽  
Diffusional Flow ◽  
Corrosion Initiation Time

Corrosion initiation time of steel reinforcement in a chloride environment—A one dimensional solution

1997 ◽  
Vol 39 (4) ◽  
pp. 739-759 ◽  
Author(s):  
P. Arora ◽  
B.N. Popov ◽  
B. Haran ◽  
M. Ramasubramanian ◽  
S. Popova ◽  
...  
Keyword(s):  
Steel Reinforcement ◽  
Initiation Time ◽  
Dimensional Solution ◽  
One Dimensional ◽  
Corrosion Initiation ◽  
Corrosion Initiation Time ◽  
Chloride Environment

Probability Model of Corrosion Initiation Time of Steel in Concrete Structure in Chloride Environment

2011 ◽  
Vol 243-249 ◽  
pp. 5632-5636
Author(s):  
Ya Li Ma ◽  
Ai Lin Zhang
Keyword(s):  
Sensitivity Analysis ◽  
Probability Distribution ◽  
Probability Model ◽  
Chloride Concentration ◽  
Initiation Time ◽  
Distribution Law ◽  
Corrosion Initiation ◽  
Corrosion Initiation Time ◽  
Chloride Environment ◽  
Distribution Type

Probability distribution law of corrosion initiation time of steel in concrete under chloride environment is discussed. Based on the Fick’s second law, by Monte Carlo, frequency distribution, distribution type and probability density is analyzed. The statistic parameters of the factors influencing the probability distribution of corrosion initiation time are studied and the expression for sensitivity analysis of corrosion initiation time is deduced. By sensitivity analysis can know, corrosion initiation time is found to be more sensitive to cover than the diffusion coefficient, and more sensitive to surface chloride concentration than the critical chloride level. The analysis of the paper perfects the methods of predicting the corrosion initiation time.

CORROSION INITIATION TIME FOR REINFORCED CONCRETE MEMBERS ALONG INDIAN COASTS: EFFECTS OF TEMPERATURE AND RELATIVE HUMIDITY — A PROBABILISTIC APPROACH

2008 ◽  
Vol 15 (06) ◽  
pp. 539-553
Author(s):  
SATISH B. ALLAMPALLEWAR ◽  
A. SRIVIDYA
Keyword(s):  
Diffusion Coefficient ◽  
Relative Humidity ◽  
Probabilistic Approach ◽  
Chloride Concentration ◽  
Threshold Value ◽  
Chloride Ingress ◽  
Initiation Time ◽  
Corrosion Initiation ◽  
Concrete Members ◽  
Corrosion Initiation Time

Corrosion initiation time of steel reinforcement for partially saturated concrete members subjected to chloride ingress is investigated at five places along Indian coasts using simplified probabilistic analysis and sensitivity of the parameters to reinforcement corrosion is studied. Previously proposed diffusion based chloride ingress model for constant surface chloride concentration and variable diffusion coefficient is used. Corrosion is initiated when the chloride concentration on steel reinforcement exceeds a threshold value. The various input parameters considered in the model are surface chloride concentration (Cs), chloride threshold value (Cth), Concrete cover (X), reference diffusion coefficient (Dref), age (t), reference age (tref), diffusion decay index (m) and monthly temperature and relative humidity correction factors f(T) and f(h) respectively; to reference diffusion coefficient. For prediction of corrosion initiation time temperature and relative humidity data collected by India metrological Department is used and all other parameters are assumed same. A large variation in corrosion initiation time is found and therefore it becomes necessary to consider the temperature and relative humidity data in a region. Life-365 considers fully saturated condition of concrete and thus underestimates the corrosion initiation time of a reinforced concrete member. The deterministic approach uses mean values of the parameters and provides a 50% probability of corrosion initiation but the probabilistic approach provides expected time of first corrosion for chosen risk of corrosion and also gives sensitivity of parameters to probability of corrosion. Corrosion initiation time in ascending order is found at Colaba, Kanyakumari, Santacruz, Chennai and Vishakhapatnam. Corrosion initiation time is useful for owner, designer, or to an organization to take decision in time of priority of repairs, repair strategy, corrosion protection in order to optimize maintenance planning and budgeting. Planned maintenance at the optimum time is the safest and most cost effective approach.

Ensemble machine learning model for corrosion initiation time estimation of embedded steel reinforced self-compacting concrete

Measurement ◽  
2020 ◽  
Vol 165 ◽  
pp. 108141
Author(s):  
Babatunde Abiodun Salami ◽  
Syed Masiur Rahman ◽  
Tajudeen Adeyinka Oyehan ◽  
Mohammed Maslehuddin ◽  
Salah U. Al Dulaijan
Keyword(s):  
Machine Learning ◽  
Time Estimation ◽  
Learning Model ◽  
Initiation Time ◽  
Self Compacting Concrete ◽  
Corrosion Initiation ◽  
Ensemble Machine Learning ◽  
Machine Learning Model ◽  
Corrosion Initiation Time

scholarly journals The Effect of Shape on Chloride Penetration of Circular Reinforcement Concrete Columns and Its Durability Design

2020 ◽  
Vol 10 (2) ◽  
pp. 459
Author(s):  
Gu Yin ◽  
Li Pan
Keyword(s):  
Diffusion Model ◽  
Chloride Diffusion ◽  
Model Parameters ◽  
Geometrical Shape ◽  
Initiation Time ◽  
Minimum Thickness ◽  
Corrosion Initiation ◽  
Durability Design ◽  
Corrosion Initiation Time ◽  
The Impact

The reinforced concrete (RC) circular element is usually simplified as slab one on the issue of chloride diffusion simulation, without considering the effect of the geometrical shape. In the paper, a modified slab diffusion model is proposed for circular section. A formulation for estimating the error caused by neglecting the effect of shape on chloride diffusion is derived. The formulation demonstrates that radius significantly affect the error. When shape is neglected, the effects of model parameters, including the diffusion coefficient, radius, cover concrete thickness and age factor, on the corrosion initiation time are investigated. The result shows the radius has a slight effect on calculating the corrosion initiation time compared with other model parameters. Furthermore, the influence of shape on estimating on reliability index for different service time is also discussed. A guideline is proposed for properly using the modified slab diffusion model instead of the original one to predict service life. Finally, the impact of the shape of the RC circular column on the durability design against chloride corrosion is studied. The design result when the column is simplified as a slab element indicates a lower required minimum concrete cover thickness. The minimum thickness should be improved by 5 mm as a conservative choice based on the result of the slab element.

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