The ICF system has three main elements
Polystyrene blocks
The polystyrene block system is a set of interlocking parts for building warm, airtight homes and other buildings.
Rebar
Rebar is essential for the strength, safety and service life of the structure. Concrete is very strong in compression, and the steel bars take the tensile and bending loads it cannot carry on its own.
Concrete
Concrete is the main structural element: it gives the wall its strength, load-bearing capacity and long life. It makes the wall rigid and resistant to pressure, fire and external impact.