New corrosion resistant steel grade for marine applications
AMLoCor, ArcelorMittal’s new ‘low corrosion’ steel grade will undoubtedly revolutionize the design of port structures. One concern of designers and port authorities is the durability of marine structures like quay walls, breakwaters, jetties.
The main advantage of AMLoCor is a significant reduction of the corrosion rates in the ‘Low water zone’ and in the ‘Permanent immersion zone’, especially since in most cases the maximum bending moments, and consequently the steel stresses, are in the permanent immersion zone.
In-situ tests have proven that the loss of steel thickness of AMLoCor is reduced by a factor 3 to 5, depending on the exposed zones (see figure below). As a reference, in Eurocode 3 Part 5, tables with typical corrosion rates can be found, valid for standard carbon steel, in northern European countries.
|Typical loss of steel thickness in a marine environment|
Compared to the unprotected steel piling solution the use of AMLoCor leads to considerable savings in steel weight, as soon as loss of steel thickness due to corrosion in the immersion zone is significant. Cathodic protection or coatings can be an alternative solution to increase the service life of a sheet pile structure, however, AMLoCor will in many cases yield the cheapest solution in the long-term.
In addition AMLoCor protects steel from ALWC (Accelerated Low Water Corrosion) which is related to biological activity enhancing degradation of steel in the low water zone.
Mechanical properties of AMLoCor grades are fully equivalent to normal piling grades, so that design structural resistances can be determined according to all relevant design codes used for steel sheet piling structures, like EN 1993-5:2007.
Port of Shoreham in the UK installed an anchored quay wall approximately 30 m long in 2010, with one anchor level, and a retained height of 8.7 m. The design required AZ 37-700 sheet piles in AMLoCor Blue 355 steel grade, with a yield strength of 355 MPa.
You will find more detailed information in the new brochure ‘AMLoCor’:
- part 1: contains general information about the new steel grade and the design approach with AMLoCor.
- part 2: contains the steel properties and chemical composition of AMLoCor, as well as the available sheet pile sections in AMLoCor. Please check regularly for new updates.
- part 3: (under preparation) will contain a design example comparing three different solutions.
|New brochure AMLoCor part 1||New brochure AMLoCor part 2|
Please contact us for further information on AMLoCor: firstname.lastname@example.org
Released on 03/11/2011