Title
Early stage beneficial effects of cathodic protection in concrete structures
Author
Polder, R.B.
Peelen, W.H.A.
Neeft, E.A.C.
Stoop, B.T.J.
TNO Bouw en Ondergrond
Publication year
2010
Abstract
Over the last 25 years, cathodic protection (CP) of reinforced concrete structures suffering from chloride induced reinforcement corrosion has shown to be successful and durable. CP current causes steel polarisation, electrochemical reactions and ion transport in the concrete. CP systems are designed based on experience, which results in conservative designs and their performance is a matter of wait-and-see. CP systems can be designed for critical aspects and made more economical using numerical models for current and polarisation distribution. Previously, principles of numerical calculations for design of CP systems were reported. The results were satisfactory, except in terms of current density for active corroding systems. This was suggested to be due to neglecting beneficial effects of CP current flow. One of the beneficial effects is pH increase at the steel surface due to oxygen reduction. As the pH increases, the corrosion rate decreases and the current demand decreases. A simple model was set up for this transient process, suggesting that such effects should occur on the time scale of hours to days. This model was validated from start up data of a CP field trial system on part of a bridge. Field results confirmed the modelling proposed here. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Subject
Architecture
cathodic protection
concrete
numerical modelling
reinforcement corrosion
Beneficial effects
Concrete structures
Current flows
Electrochemical reactions
Field trial
Ion transports
Numerical calculation
Numerical modelling
Numerical models
Oxygen Reduction
Polarisation
Reinforced concrete structures
reinforcement corrosion
Start-ups
Steel surface
Time-scales
Transient process
Cathodic protection
Chlorine compounds
Computer simulation
Concrete beams and girders
Corrosion rate
Electrochemical corrosion
Electrolytic reduction
Numerical methods
Oxygen
pH effects
Polarization
Reinforced concrete
Reinforcement
Structural design
To reference this document use:
http://resolver.tudelft.nl/uuid:b1fc7ff2-5def-4c27-8dd7-e2533f34c850
DOI
https://doi.org/10.1002/maco.201005803
TNO identifier
425584
Source
Materials and Corrosion, 61 (2), 105-110
Document type
article