Concrete mixing system

A mixing tool for mixing, in a mixing container with a predetermined internal shape, plural materials including a first material, which is a liquid, and a second material, which is a dry mix;

• said mixing tool comprising:
• a shaft with a first mixing member fixedly positioned at an axial bottom end of the shaft;
• wherein said first mixing member is an elongated, substantially rectangular plate having a plate length which is greater than a plate height and which length extends along a direction that is substantially perpendicular to the shaft axis, and the shaft axis lies along the profile of the plate;
• said first mixing member comprising an upwardly facing plate length top edge;
• the plate top edge includes, between opposing lengthwise ends:
• a first notch, a first bottom of which defining a first visual reference located at a first predetermined distance from a bottom of the shaft;
• and
• a second notch, a second bottom of which defining a second visual reference located at a second predetermined distance from a bottom of the shaft which differs by its distance from the bottom of the shaft as compared with the first bottom of the first notch;
• wherein, when the bottom of the shaft is against an interior bottom of the container:
• a first slurry concentration is consistently obtained by filling the container with a first predetermined amount of the dry mix and a first predetermined amount of the liquid to the first notch and mixing;
• a second slurry concentration is consistently obtained by filling the container with a second predetermined amount of the dry mix and a second predetermined amount of the liquid to the second notch and mixing;
• and
• the first and second slurry concentrations are consistently substantially the same.