What are the recent changes to ASTM A123?

ASTM has balloted a few changes to ASTM A123 to add some clarity to the repair requirements, to specifically address the acceptance of skimmings in final inspection, and to reference the specification for continuous galvanized rebar in the scope section.  It has always been difficult to describe the area on the galvanized parts that can be repaired through ASTM A780.  The proposed change includes new language to further identify the maximum size of an area that can be repaired, as well as a drawing of two areas to be repaired to show in pictorial form the acceptable and rejectable repair areas.  The change also includes language to address repairs to galvanized parts in the field where there is no minimum size for areas to be repaired.  This change has been approved through the ASTM balloting and a new version of A123 will be published in the next couple of months. The AGA Blue Book of Selected Specifications will not be updated this year but an insert with the changes will be provided in all copies purchased until new AGA books are ordered from ASTM. This is likely about two years away based on current inventory.

The second proposed change to A123 addresses the acceptance or rejection of areas of galvanized skimmings on the surface of the coating.  Since the galvanized coating is complete under the skimmings, the presence of skimmings on top of the coating is not cause for rejection.  The change goes on to say that for appearance reasons the skimmings can be brushed off the surface or washed off.  Some skimmings may need to be ground off the surface making sure to avoid taking off too much zinc so the coating thickness no longer meets the minimum requirement.  This change had one negative vote and the ASTM editor reviewed the editorial change and agreed with the change being classified as editorial so the ballot is now passed and will be included in the next revision of A123.

The third proposed change to A123 is to reference in the scope of the specification the newly accepted specification on continuous galvanized rebar, A1094.  The reference directs the reader to go to A1094 for requirements specific to reinforcing steel that is galvanized by the continuous process.  This change has been approved through the ASTM balloting and a new version of A123 will be published in the next couple of months.

Another specification under consideration for language changes is ASTM A385.  This is the specification that describes the chemistry of the steel affecting the coating thickness and appearance.  This is a tricky subject since the combination of silicon and phosphorus can introduce thick and dull coatings even when both elements are in supposed safe regions.  The chemistry of the steel is measured through a sampling of the steel heat reported on a Material Test Report (MTR), and this can also provide questionable evidence for silicon and phosphorus content that can be directly linked to the coating thickness and appearance.  The specification change attempts to give more information on the use of MTR values for silicon and phosphorus in anticipating the coating thickness and appearance.  Specifiers should not set limits on steel chemistry since even silicon values in the middle of the Sandelin region or beyond silicon content of 0.25% can produce acceptable corrosion protection.  This change has been approved through the ASTM balloting and a new version of A385 will be published in the next couple of months.