I live in a large grain farming area. I see lots made of concrete, and lots made of horizontally ribbed metal rings. Very nice work on all of the details. edit: sort of like this
The material is confused because the of the tiled lines you put in, that make it seem like planks. Lose those lines if you want it to be concrete. I don't see them in the reference either. Everything else looks really nice, though.
since i live in Iowa - the land of "Silos and Smokestacks" according to one state boarder sign, I would say I've seen a few silos, while they can be made from a variety of materials, the majority of silos in Iowa seem to be made in the same way from concrete blocks(it's likely from the same company -…