What material is it made Hall

Rounded halls without pillars are made by NAVELI CONSTRUCT after a new american technology, that use galvanized sheet or prepainted in rolls, folded at a certain opening, between 12-36m. Galvanized sheet can have a thick layer of zinc 70-275g/mp. Prepainted sheet, also can have a thick layer of zinc 70-275g/mp, and over zinc are applied several layers of polymers, about 20 layers on the outside and 7 on the interior.  Hall rounded advantage made from prepainted sheet is that each beneficiary is able to build a hall in their desired color.