permanent formwork
lost formwork

BCA investigates Hybrid permanent formwork.

This is termed a 'bubble-reinforcement' sandwich, which is then cast into bottom layer of 60 mm pre-cast concrete, encasing the bottom mesh reinforcement, to provide permanent formwork within part of the overall finished slab depth.

A norm was presented by which all walls and framework were to be realized in concrete and the lost formwork in artificial stone, incorporating the visible decoration.