Terms & Conditions
Work Group H
Durability: Sacrifical steel, ALWC, coatings, cathodic protection, new steel grades
David Rowbottom - Tata Steel Steve Cross - Royal Haskoning
David Baxtor - ArcelorMittal
Mike Hodgson - BAM Nuttall
The corrosion process – a general introduction.
The long term performance of steel products exposed to the elements has been studied for
many years by both academia and the steel manufacturers which has not only established
the factors that influence the corrosion process but also allowed methods for addressing the
effects to be developed.
The group will produce a general introduction to the corrosion process indicating the factors
that affect the performance of steel elements in different environments.
Deliverables: Report and presentation
The corrosion process – special situations.
General corrosion activity will apply to the vast majority of piling locations but there will be
extreme cases where the effects of corrosion differ significantly from the norm. An example
of this is the phenomenon of Accelerated Low Water Corrosion (ALWC) which can have a
devastating effect on construction products if the cause is not dealt with.
The group will produce a report on the subject including definitions of MIC and ALWC, field
identification of the problem and methods of addressing it on new and established
The corrosion process – Design
The durability of a proposed solution needs to be established to ensure that it offers the
most cost effective solution to the problem. Codes of practice for the design of steel piles (ie
EN1993-5) provide designers with information concerning the rate of corrosion to be
adopted when assessing life expectancy.
The group will prepare sample calculations for sheet and high modulus piles, UBP/UC
bearing piles and marine tubes which demonstrate how the life expectancy of a particular
element can be determined and how that life expectancy can be enhanced by the
introduction of additional measures. The cost effectiveness of the various proposals will be
demonstrated by assessing the cost of each option.
Deliverable: Calculation sheets and list of current costs
The corrosion process – Protective systems
The durability of steel elements can be enhanced by the introduction of protective measures
ranging from barriers (ie paint or concrete encasement) which separate the steel from the
corrosive environment to systems that interrupt the electrochemical process (ie cathodic
protection). It is also possible to specify steel chemistries that are naturally more resistant to
The group will prepare a report outlining the available options for enhancement of the life
expectancy of steel elements including an assessment of the life of each system and
maintenance implications and will attempt to provide real costs for the various options.
Updated by Mark Bramley, 06/03/2013
Printer friendly page
Provided by Webforum