Currently, the only reaction that makes CNCT is pressurizing molten ROCK; this is quite slow and also makes BRMT/BMTL.  So I propose a new way to make CNCT production lines that is faster and doesn't leave us with less finished product than raw material:

PSTE mixes with SAND to make PSTE(SAND); while normal PSTE turns hardens into BRCK at 474C, PSTE(SAND), instead, hardens into CNCT at this temperature.

@jansuki (View Post)

 What is "why do you need cnct" supposed to mean?

I would also give SAND another practical application besides GLAS production.  Real life concrete is made with sand anyways, so it would also add more realism.