Precast concrete roof without reinforced concrete topping [RC4] - jcgomezz/Building_taxonomy GitHub Wiki

Precast concrete units without a reinforced concrete topping. Precast units include hollow-core slabs, solid slabs, or a system of precast concrete joists with timber or hollow concrete infill. Sometimes overlaid with light-weight roofing.

Precast concrete hollow core slabs (tropicalconcrete.com)