I was thinking the same thing. The only welding I can think of is steel studs to a plate and that’s done with a stud gun. It’s pretty hard to screw up that, and there’s no credentials required. Rebar is overlapped and tied. Sometimes an exposed plate in a piece of precast has something welded to it, but that’s not for structural purposes usually. Sometimes a cross brace between two girders, but once the deck is poured, how much are those contributing? Girders are generally bolted if built up steel sections. If precast concrete, then they secured by a poured in place bulkhead.
I think the only welding the mexicans are doing is on some false work. That’s all tore down before any traffic crosses.
Cadwelding is done only when the engineer requires it!
Not done very much anymore.
I can remember when Americans tyed rebar.
Black, White, Lumbi Indians fron NC were big into it!