Listed below in Table 1, are the main protective coating system guides and standards that have been available for the current generation of specifying structural engineers in Australasia.

The earliest available was the British Code of Practice 2008 from 1966, which became BS 5493 in 1977. This was the basis for AS 2312 first published in 1980. AS 2312 It was updated in 1984, again in 1994 when it was made a combined standard, and updated again in 2002.  The ISO 12944 series has since replaced BS 5493.

In 2014, AS/NZS 2312 was split into 3 parts and ten years later Part 3 may finally be published! Note that the amended version of Part 1 published in 2017, which corrected printing errors in the original 2014 version, is unfortunately no longer a joint AS/NZS Standard.

Table 1. Protective coatings

BS CP 2008:1966 Code of Practice for Protective coating of iron and steel structures against corrosion

BS 5493:1977 CoP for Protective coating of iron and steel structures against corrosion (revised 1984 & 1993)

AS 2312:1980 Guide to the protection of iron and steel against exterior atmospheric corrosion (revised in 1984 and made a joint AS/NZS standard in 1994)

ISO 12944:1998 (in 9 parts that superseded BS 5493, last revised in 2018)

AS/NZS 2312:2002 Guide to the protection of structural steel against atmospheric corrosion by the use of coatings

AS/NZS 2312:2014 Split into Part 1: Paint coatings, Part 2: Hot dip galvanizing & Part 3: TMS coatings (in prep.)

AS 2312.1 / Amdt.1/ 2017-10-18

SNZ TS 3404: 2018 Durability requirements for steel structures and components

Guides and standards for Thermal Metal Spray coatings have been around since at least 1955.  BS 2569 was included in the specification for the first four lanes of the Auckland Harbour Bridge that was completed in 1959. (Its first coat was 50 microns of flame-sprayed zinc).  The US Army Corps of Engineering developed a very comprehensive manual for the use of thermal spray on their hydraulic structures, which is a useful reference.

Our 1994 edition of AS 2312 referenced ISO 2063 which has been progressively updated over the years.  Its 2017 version was initially considered as basis for Part 3 but not considered suitable for adoption without significant modification. In the meantime, NACE and SSPC adopted and updated the 1993 American Welding Society Guide C2.18.

Available application specifications listed in Table 2 include the ones produced by Shell Global and the American Association of State Highway and Transportation Officials (AASHTO).  These have also been referenced in developing the latest draft of Part 3 being finalised by an ACA Working Group, which should be available from Standards Australia for public comment in the near future.

Table 2. Thermal spray

BS 2569. Sprayed metal coatings: Part 1:1955 Protection of iron and steel against atmospheric corrosion (Superseded by BS 2569 (1964) and BS EN 22063:1994)

EM 1110-2-3401 (1999) Thermal Spraying: New Construction and Maintenance, US Army Corps of Engineers: Engineer Manual

ISO 2063:1991 Metallic and other inorganic coatings – Thermal spraying – Zinc, aluminium and their alloys (superseded EN 22063:1994, revised in 2005 and re-issued in two parts in 2017 and last revised in 2019)

NACE No.12/AWS/SSPC C2.18 Guide for the protection of steel with thermal sprayed coatings of aluminum and zinc and their alloys and composites (2003) (based on 1993 ANSI/AWS standard – revised in 2016)

Shell DEP (2005) Thermal spray coatings of aluminium and 85/15 zinc/aluminium alloy (revised 2008 and 2017)

AASHTO/NSBA S8.2, SSPC-PA 18 (2017) Specification for the Application of Thermal Spray Coatings on Steel Bridges

NZTA S9: Part 3 (2020) Specification for coating steelwork on highway structures with thermal metal spray

Matt Vercoe, NZ.

The above is an extract from a presentation to the ACA Coatings Technical Group Forum by Willie Mandeno at Corrosion & Prevention 2023 in Perth this November. Get Tickets!


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