How do you remove the glazing of ceramic tiles?

[Caloy B]

My thesis is about replacing coarse aggregates in concrete specimens with ceramic tiles. The problem is I have to deglaze the tiles before we can pour. Right now Im using a hammer and chisel. Is there a faster way to deglaze these tiles?

[trent0123]

Washing in hydrofluoric acid might work, but it's too slow and dangerous.
Grinding is labor intensive and makes a lot of dust.
You can probably get a fairly rough surface on the glazed pieces by tumbling them with other rocks in something like a cement mixer for some time before using the batch.
That may take a few days, but it is less dangerous and less labor intensive than the first 2 ideas. Big batches would be more economical than many small batches.