Depending on what is desired in each case and the conditions of the work, additives may be used in cement grouts.
The use of additives should be limited to the maximum, only using them when absolutely necessary.
The pressure is always measured at the entrance to the hole and depends basically on three factors:
a) The size of the voids of the terrain, i.e. its permeability;
b) Viscosity of the grout; Obstacles that the grout finds until reaching the ground, such as the manchettes elements and the previous sealing or filling grouting.
c) Time spent on operations