Quote:
Originally Posted by natelox
Concrete can be ductile with the addition of reinforcing steel. Steel construction is very much a column and beam system. Concrete can be (and is very often) built in this manner, but concrete shear walls offer much better lateral resistance than the moment frames or tension rods typically seen in steel construction. Shearwalls, especially massive (as in weight) ones, dissipate energy more readily than moment frames or tension rods.
Concrete columns are protected from lateral forces by the reinforcing ties. Circular columns have better seismic resistance than square because of the nature of the rebar. Circular columns use a spiral rebar to tie the vertical rebar together. If the concrete cracks or shatters because of an earthquake, the helical rebar ties will keep the broken pieces in place, and the column will retain its ability to resist compression.
Furthermore, there is the added advantage that concrete is always fireproof, and steel needs an applied fireproofing. Since fires typically do as much damage, if not more, than lateral movement during the aftermath of seismic activity, concrete may be more beneficial (Fire is dangerous post-seismic activity because underground water supply lines tend to rupture, rendering fire-hydrants and fire-fighters without water). Fire-rated gypsum board, which typically protects steel, could easily fail during significant lateral movement.
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I agree very much with this. However, the blame on the steel, well, I don't call it steel, its a form of metallurgy. I should have said this before, its not steel, its so many varieties of different elements. ASME, ASTM have a variety of code that can be mixed with polymers, other elements and even concrete that are more withstanding that simple rebar and Concrete. Cost withstanding, probably and issue. I work in the LNG pressure vessels and Nuclear reactors, so its probably more of an issue with us than fabrication of buildings.