Or, why does cement curl at all?
heat genorated from the saw blade and the fact that the blade is spinning in an upward rotation has something to do with it.
Because one side is drier then the other. It tends to curl towards the drier side. You can get the same effect from cutting certain types of fruit. This only happens to cement that is approaching hardness.
I have never seen cement curl, possibly don't understand- sorry. As far as dryness. Concrete when poured starts to cure and set immediately. The outer edges cool or cure faster than the inside area because there is more sq inches exposed to the air. Sometime in the late evening go out barefoot and stand on a sidewalk that has been in the direct sunlight during the day. You will notice if you put your foot on the edge it is much cooler than the middle - same thing the edge has more surface and edge exposed to allow it to cool quicker. Sorry about the curling - I just didn't understand - my fault.
