The specification ASTM A/AM is applicable exclusively to the hot-dip galvanizing of reinforcing steel, otherwise known as rebar (Figure 13), and is. 25 Jan ASTM A, Standard Specification for Zinc-Coating (Galvanized) Steel Bars for Concrete Reinforcement first and foremost specifies the. 11 Jan Galvanizers are mandated to follow the requirements listed in ASTM A/ AM, which is the “product standard.” Galvanizers are not.
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As this evolved hydrogen gas travels through the concrete matrix toward the surface, voids can be created which weaken the bonding with the concrete or disturb the smoothness of the concrete surface. Within the text, the SI units are shown in brackets. ASTM A does not apply to wire, astm a767, tube, or steel sheet which is galvanized on specialized or continuous lines. ASTM A also contains information on minimum coating thickness astm a767 well as finish and adherence requirements.
The mass of the coating shall be determined by magnetic thickness gage measurements. Work Item s – proposed revisions of this standard. The values stated in each system may asttm be exact equivalents. A retest shall be provided if the average zinc coating mass fails to meet the astm a767. Combining values from astm a767 two systems may result in non-conformance with this specification.
astm a767 Minimum bend diameters for finished bars are included in the specification to prevent the coating from flaking on bend radii, as are requirements for coating thickness according to bar size. This specification covers steel reinforcing bars with protective zinc coatings applied by dipping the properly prepared reinforcing bars into a molten bath of zinc. Rebar is commonly bent prior to the hot-dip galvanizing process.
The main specifications that pertain to hot-dip galvanizing are:. Ashm notes and footnotes excluding those in astm a767 shall not be considered as requirements of astm a767 specification. However, this single product specification introduces a few new requirements that apply solely to hot-dip galvanized rebar. Stripping method, weighing before and after galvanizing, and microscopy method astm a767 be used to referee the results obtained by magnetic thickness measurements.
It satm both un-fabricated products and fabricated products, for example, assembled steel products, structural steel fabrications, large tubes already bent or welded before galvanizing, and wire work fabricated from uncoated steel wire. However, wire is not included.
These specifications have slightly different requirements for coating thickness, ashm most refer back to the ASTM astm a767, and by following ASTM specifications the galvanizer will meet the requirements outlined in them.
It is informational astm a767 and not an official part of the standard; the full text of the standard itself must be referred to for its use and application. The galvanized coating shall be chromate treated.
ASTM A767 for Reinforcing Steel
Astm a767 order astm a767 help prevent and suppress this reaction, hot-dip galvanized rebar is dipped into a dilute chromate quench solution after being removed from the galvanizing kettle.
It is intended to astn applicable to hardware items that are centrifuged or otherwise handled to remove excess zinc. The galvanizer is identified throughout this specification as the manufacturer.
The galvanizer shall be permitted to subject the newly coated steel reinforcing bars to air or steam wiping to remove excess zinc from the bars. In addition, since astm a767 is handled frequently during its installation, any tears or sharp spikes that make the material dangerous to handle astm a767 grounds for rejection.
Table 5 below gives recommendations for bend diameters based upon the bare steel bar diameter before coating. asmt
Galvanization shall be used to prepare reinforcing bars. The specification includes minimum coating thicknesses according to material category as well as finish and adherence requirements.
Astm a767 are some other specifications for hot-dip galvanizing you occasionally see used in North America. Steel reinforcing bars bent cold prior to hot-dip galvanizing should be fabricated asgm a bend diameter equal to or greater than the specified values. Therefore, each system shall be used independently of astm a767 other. Historical Version s – view previous versions of standard.
ASTM A for Reinforcing Steel | American Galvanizer’s Association
Historical Version s – view previous versions of standard Work Item s – proposed revisions of this standard Translated Version s: This astm a767 also introduces a new astm a767 to the galvanized coating known as chromating. Link to Active This link will always route to the current Asstm version of the standard.
Hot-dip galvanizing is done in accordance with long established ASTM specifications. The main specifications that pertain to hot-dip galvanizing are: Newly galvanized steel can react with wet concrete and potentially form hydrogen gas as a product. This specification also covers steel forgings aetm iron castings incorporated into pieces fabricated before galvanizing or which are too large to be centrifuged or otherwise handled to remove excess galvanizing bath metal.
ASTM does not give asmt warranty express or implied or make any representation that the contents of this abstract are accurate, complete or up to date. The mass astm a767 zinc coating shall conform to specified requirements. This abstract is a astm a767 summary of the referenced standard.
Referenced Documents purchase separately The documents astm a767 below are referenced within the subject standard but are not provided as part of the standard.