Prefabricated hollow concrete slab for building - has cores removed before completion of hardening within external formwork

摘要

The prefabricated concrete building slabs have hollow chambers. The slabs have a large surface area and a a small number of chambers, whose width is greater than twice their height. The cores of variable dimension are held in external formwork and the concrete subjected to accelerated hardening. The core formwork (11) is removed from the hollow slabs before the full strength of concrete has been reached. The hollow slabs continue to harden up to their final strength before their removal from the external formwork which has travelling pallets. The cores are removed sideways from the concrete in the hardening tunnel (1) after which the hollow slabs continue to travel along the tunnel.