1 minute ago, joe90 said:

Yup, some scientist thought it was a good idea 🤷‍♂️

 

I think it was untested aggregate that was the issue. Concrete blocks will initially appear sound but as the pyrite oxidises internally the completely dissolve. 

 

Plenty of videos on YouTube showing the scale of the issue. Children crushing concrete blocks much like rice Krispie cakes. I feel sorry for the people involved. 

 

Their houses are literally falling down. 

I remember fly ash from coal power stations being used to make "insulated" lightweight blocks in the 80's often used as the inner leaf as my first house was. Horrible things to fix anything to they were so soft even when new.  I wonder how they are bearing up?