Anyone who has had the pleasure of removing set cement from a machine will appreciate this. On smaller mixers some holes drilled and a few gallons of acid help and if lucky big bits can be broken out after a week or two then tumbling large rocks can help. Worst case is some poor monkey has to put in ear plugs, stuff their grade 5 earmuffs with cotton waste, put on the breathing gear and get in with a rock-breaker finishing off with an air chisel in the tight bits.
I thought this was far better. 100 MPa Carbon fibre reinforced concrete!