If they used it in Britain they must of used it here ...What is RAAC?
Reinforced autoclaved aerated concrete (RAAC) is a lightweight material that was used mostly in flat roofing, but also in floors and walls, between the 1950s and 1990s.
It is a cheaper alternative to standard concrete, is quicker to produce and easier to install.
It is aerated, or "bubbly", like an Aero chocolate bar.
But it is less durable and has a lifespan of around 30 years.
Its structural behaviour differs significantly from traditional reinforced concrete.
Moreover, it is susceptible to structural failure when exposed to moisture. The bubbles can allow water to enter the material.
If that happens, any rebar reinforcing RAAC can also decay, rust and weaken.
Because of this, RAAC is often coated with another material, such as bitumen on roofing panels. But this material can also degrade.
The Standing Committee on Structural Safety (SCOSS) noted that: "Although called 'concrete', RAAC is very different from traditional concrete and, because of the way in which it was made, much weaker."
According to Loughborough University, there are tens of thousands of these structural panels already in use and "many are showing signs of wear and tear and deterioration".
The Health and Safety Executive says RAAC is now beyond its lifespan and may "collapse with little or no notice".
DID our Government know about this Why did they pull down Ballymun and St Michaels Estate ?Imagine if this Concrete was used in the Old Shannon or Dublin Airports ?Probably explains why they part remodeled the Legoland Houses with Flat concrete roofs in Cherryorchard and Old Bawn ?
