Hello everyone, could you kindly advise if there is any upper limit on the percentage of recycled steel and/or EAF-made steel that can be used in buildings (whether high-rise or low-rise) from the standpoint of safety and structural integrity? We are hearing conflicting information from various parties on this point. Any references to scientific/peer-reviewed papers would be especially helpful. Thanks!
Hi Vikitoo - modern EAF produced steel is practically indistinguishable from BOF produced steel. As always, you should be specifying the grades required, which will define the steel chemistry and heat treatments required. I always recommend positive material identification is undertaken for critical members to ensure that the steel received is what was ordered. Quality control during fabrication also needs to be specified to ensure that the steel is not compromised, e.g., by poor welding practices.
Hi Will - Many thanks for the prompt feedback and the detailed explanation. Regarding the EAF produced steel and the positive material identification process, would be much appreciated if you could advise below questions. Thanks!
- Since EAF rebar is indistinguishable from BOF-produced steel, could we assume the qualify of both routes manufactured steel should be the same if we specify the grades required? Any difference in structural design and safety concerns?
- Is there any worldwide recognized certification or standard procedure protocol that could ensure the positive material identification process?
Generally, yes you can specify to the ASTM, ASME, or whichever local codes apply, and the quality should be the same - it is actually unlikely that the supplier with report the BOF / EAF content unless you specifically ask. There are ASTMs for PMI, that will depend on the specific requirements and methods used, I would start with ASTM A751 and ASTM E1476.