On 21/03/2019 21:06, Kipper at sea wrote:
Red Ash is burnt out coal spoil waste. Its found in the middle of
coal mine slag heaps. It was used to fill in the middle of houses to
bring the floor level up then a concrete screed lay on top. It was
found that some of the acids in the ash caused the screed to
disintegrate.

Indeed. Suphurous coal will in addition to meiting Sulphur oxides make
certain sulhur style comounds with te dah, taht can turn to sulphuhuric
acid when wet.

Turning cement from insoluble carbonates to soluble sulphates over time.
Same as brick acid.


--
"In our post-modern world, climate science is not powerful because it is
true: it is true because it is powerful."

Lucas Bergkamp