The decision to close some schools and erect emergency structural supports in others just days before the start of a new term appeared to come about suddenly. The announcement followed three recent failures of reinforced autoclaved aerated concrete (Raac), in particular the collapse of a beam in late August at a primary school in Leicester.
Click here for original story, Concrete crisis: Officials thought asbestos in schools was safe too—the same mistakes have been made over Raac
Source: Phys.org