Precast Columns (H – Section) used to construct the precast compound walls. first of all dig into earth and make pocket, align column into pocket and fill concrete side of those columns.
H section columns use into precast concrete wall to support and hold the panels against wind or any type of pressure.
this type of columns reinforce with HT wire or iron rods, but reinforcement with HT steel with pre-stressed will save iron weight with desire strength and after rust iron bar will take role into concrete cracks at the same time HT steel will not take role for same.
as it is pre-cast so, it is obvious that it manufactures at factory and transport to the location where needed