If you have chosen to continue with 0.8:1 grout after the first 15 minutes it is certainly time to thicken to
0.6:1. Otherwise far too much water is being injected.
However, if you were using 0.6:1 it would be best to thicken to 0.5:1 if you assume that the mixer can handle
such a thick mix .
It is necessary to decide what to do next. The choice is from one of the following: