scholarly journals Especificaciones de cálculo de la vida útil y estado límite de corrosión

2013 ◽  
Vol 3 (2) ◽  
pp. 79-97 ◽  
Author(s):  
C. Andrade
Keyword(s):  
Service Life ◽  
Diffusion Coefficients ◽  
Prediction Models ◽  
Concrete Structures ◽  
Surface Concentration ◽  
Panama Canal ◽  
Present Communication ◽  
Limit Values ◽  
Aging Factor ◽  
Acceptable Probability

RESUMENLos cálculos de vida útil de las estructuras de hormigón están pasando rápidamente de los laboratorios a las normativas y a ser especificados en la licitación de grandes infraestructuras. Así vidas útiles de 100 años o más se han requerido en puentes como Oresund o en el nuevo canal de Panamá. Sin embargo la especificación se realiza de forma resumida sin que se defina la forma de demostrar esa durabilidad y en algunos casos, sin siquiera mencionar los ensayos y sus valores limites que se deben utilizar. En la presente comunicación se describen los aspectos más importantes que se deben especificar en los modelos que deben ser además de los coeficientes de difusión, la concentración superficial, los factores de envejecimiento y el límite de cloruros así como la probabilidad de corrosión que se considera inaceptable.Palabras Clave: hormigón; cloruros; resistividad; difusión.ABSTRACTEstimates of service life of concrete structures are rapidly moving from laboratories to the standards and to be specified in the construction for large infrastructures. So service life of 100 years or more were required to Oresund bridge or the new Panama Canal. However, the specification is made without defining how to prove the specified durability and in some cases, without even mentioning the tests and limit values to be used. Present communication describes the most important aspects to be specified in the chloride prediction models in addition to the diffusion coefficients, which are the surface concentration, the aging factor, the limit of chlorides and the acceptable probability of corrosion.Keywords: concrete; chlorides; resistivity; diffusion.

scholarly journals Computational modeling for predicting corrosion initiation in reinforced concrete structures

2017 ◽  
Vol 10 (6) ◽  
pp. 1205-1244
Author(s):  
W. K. DOMINICINI ◽  
J. L. CALMON
Keyword(s):  
Reinforced Concrete ◽  
Service Life ◽  
Concrete Structures ◽  
Surface Concentration ◽  
Reinforced Concrete Structures ◽  
The Finite Element Method ◽  
Effects Of Temperature ◽  
Solar Radiation Exposure ◽  
Dimensional Domain ◽  
Brazilian Standard

Abstract This article presents a model for penetration of chloride by diffusion in reinforced concrete structures based on the solution of the Fick's 2nd Law, using the finite element method (FEM) in two-dimensional domain. This model predicts the time, in a given situation, so that a certain limit of chlorides for depassivation of reinforcement is reached, characterizing the end of service life. Several approaches for the chloride surface concentration and for the diffusion coefficient are used, parameter which must be corrected due to the effects of temperature, solar radiation, exposure time, and relative humidity. Moreover, a parametric analysis is carried out in order to study the factors involved and their impact on the ingress of chlorides by diffusion, contributing to a better understanding of the phenomenon. In addition, the developed model is applied to the cities of Vitória (ES) and Florianópolis (SC) to analyze the service life for different concrete covers, making a comparison with the Brazilian standard.

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.

CARBONATION INDUCED CORROSION ANALYSIS OF REINFORCED CONCRETE STRUCTURES BASED ON FULL PROBABILISTIC APPROACH – AN INDONESIAN CASE STUDY

2018 ◽  
Vol 4 (1) ◽  
pp. 165
Author(s):  
Herry Prabowo ◽  
Mochamad Hilmy
Keyword(s):  
Service Life ◽  
Probabilistic Approach ◽  
Concrete Structures ◽  
Weather Condition ◽  
Analysis Data ◽  
National Standard ◽  
Concrete Carbonation ◽  
Durability Design ◽  
Starting Point ◽  
Real Performance

The assessment of the service life of concrete structures using the durability design approach is widely accepted nowadays. It is really encouraged that a simulation model can resemble the real performance of concrete during the service life. This paper investigates the concrete carbonation through probabilistic analysis. Data regarding Indonesian construction practice were taken from Indonesian National Standard (SNI). Meanwhile, data related to Indonesian weather condition for instance humidity and temperature are taken from local Meteorological, Climatological, and Geophysical Agency from 2004 until 2016. Hopefully the results can be a starting point for durability of concrete research in Indonesia.

scholarly journals Seismic Damage Accumulation in Highway Bridges in Earthquake-Prone Regions

2015 ◽  
Vol 31 (1) ◽  
pp. 115-135 ◽  
Author(s):  
Jayadipta Ghosh ◽  
Jamie E. Padgett ◽  
Mauricio Sánchez-Silva
Keyword(s):  
Service Life ◽  
Damage Accumulation ◽  
Main Shock ◽  
Prediction Models ◽  
Time Window ◽  
Damage Index ◽  
Active Regions ◽  
Highway Bridges ◽  
Main Shocks ◽  
Aftershock Sequences

Civil infrastructures, such as highway bridges, located in seismically active regions are often subjected to multiple earthquakes, including multiple main shocks during their service life or main shock–aftershock sequences. Repeated seismic events result in reduced structural capacity and may lead to bridge collapse, causing disruption in the normal functioning of transportation networks. This study proposes a framework to predict damage accumulation in structures subjected to multiple shock scenarios after developing damage index prediction models and accounting for the probabilistic nature of the hazard. The versatility of the proposed framework is demonstrated on a case-study highway bridge located in California for two distinct hazard scenarios: (1) multiple main shocks during the service life and (2) multiple aftershock earthquake occurrences following a single main shock. Results reveal that in both cases there is a significant increase in damage index exceedance probabilities due to repeated shocks within the time window of interest.

Evaluation of service life design models on concrete structures exposed to marine environment

2010 ◽  
Vol 43 (10) ◽  
pp. 1397-1412 ◽  
Author(s):  
Irina Stipanovic Oslakovic ◽  
Dubravka Bjegovic ◽  
Dunja Mikulic
Keyword(s):  
Service Life ◽  
Marine Environment ◽  
Concrete Structures ◽  
Design Models ◽  
Service Life Design ◽  
Life Design
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