I was just walking by the national archives building in DC. It has colums put front apparently supporting the part above the colums. My question is… In modern buildings like that with columns, are they purely decorative? Load-bearing? Are they made of pure stone like ancient real columns? Or are they just fake colums shells around rebar?
Thanks
Given the age of the building, I think you can assume they are structural in nature.
I have seen brand new residential buildings going up with columns, and they are purely decorative. Some columns are made from Styrofoam-like materials with stucco on the outside.
New buildings are probably still being built with structural columns, but you would have to look at the structural drawings and materials to know for sure.
According to the Wiki, the National Archives building has solid granite and limestone facade. As you can see in this image, the columns are solid and in one piece. Based on this picture, I would say that the stone facade is supported laterally by the underlying steel frame, but it carries its own weight.
That said, anything built since 70s is likely to be reinforced concrete with nice surface finish
A common feature on McMansions these days are hollow PVC columns with steel beams inside.
Similarly, arched doorways and windows have been very popular for at least the last 50 years or so (certainly in Southern California at least, where Spanish Revival architecture has be de rigeur or however you say that in Spanish) – but these too are just façades, consisting really of modern post-and-lintel, with arches made of plaster and chicken wire.
Back to the question… The public building with columns at the front probably has a large , roof high, foyer… So no floors there to hang off the column… The front is just a facade being a shell holding itself and the roof.
I’ve seen some of those McMansions under construction, and often they will have a wood post - 4x4 or couple of 2x4s nailed - to support the porch until the fancy decorative pillar arrives and can be substituted.
If the overhang is significant, say 4 or 5 feet or more for wood houses (maybe 10 feet or more for metal frame buildings?), odds are the pillars perform some support function. They just are not the major load bearing piece of the house, it’s just simpler to rest the overhang on them rather than building it to hang out unsupported. The main walls will be the major structural element.
If they are fake shells, they probably hide structural steel columns. Rebar is reinforcing steel used for a specific reason inside poured concrete…it’s not a structural material by itself.
Who says ancient buildings had pure stone columns? The Romans were big on stone-faced concrete.
