Apparatus and method for cutting unhardened concrete

A method of cutting grooves in a concrete surface with a cutting blade having cutting segments, comprising the steps of:

• rotating the concrete cutting segments in an up-cut rotation in the concrete surface to form a first central groove with a first width and first depth and to form a second groove with a shallower depth and with a second width that overlaps the width of the first groove, the rotating step occurring before the concrete surface has reached a hardness of about 1200 psi and being performed without supplying liquid to the cutting segments;
• selecting the depth of the first groove to be sufficient for crack control, while selecting the second width of the second groove to be wider than the first width and sufficiently wide to hold enough concrete sealant to maintain sealing contact with sides of the groove during climatic variations;
• supporting the concrete surface during the rotating step at a distance sufficiently close to the second groove, and adjacent at least the portion of the cutting segments exiting from the concrete surface, so that cutting raveling of the second groove is reduced, while not trowelling over and filling in the second groove;
• and
• supporting the concrete surface during the rotating step at the location where the cutting segments exit from the concrete surface, and along a length of the cutting segments that does not exceed the difference between the depth of the first and second grooves, and at a distance sufficiently close to the first groove to reduce raveling of the concrete surface at the second groove.

A method of cutting grooves in a concrete surface comprising the steps of:

• cutting a first groove in the concrete with a rotating concrete cutting blade having an up-cut rotation by cutting before the concrete has reached a hardness of about 1200 psi;
• simultaneously cutting a second groove in the concrete substantially parallel to and overlapping the first groove and opening onto the surface of the concrete;
• selecting the depth of the first groove to be sufficient for crack control while selecting the depth of the second groove to be less than the depth of the first groove but deep enough for a sealant well, and further selecting the width of the second groove to be greater than the width of the first groove but wide enough for a sealant well;
• and
• supporting the concrete surface during the cutting at the location where the cutting blade exits the concrete, and at a distance sufficiently close to the cutting blade to produce a surface adjacent the second groove that does not ravel.