15 March 2001
joint. An additional sawcut is then made to intersect the two prevoius cuts at an
approximately 60-deg angle with a minimum distance of 14 in. (360 mm). For corner
spalls that are more rectangular in shape, a rectangular repair similar to that of a joint
spall is conducted.
Pavement and unsound concrete within sawcuts shall be broken out and removed to a
depth not less than 2 in. (50 mm) or 1/2 in. (13 mm) into visually sound concrete,
whichever is deeper. Exposed cavity surfaces shall be cleaned as specified.
Dowels, tie-bars, or reinforcing bars, or WWF exposed for more than 90 deg of their
circumference shall have the surrounding concrete completely removed to a depth of at
least 1/2 in. (13 mm) below the bar or wire. See References a, f, and i.
A groove may be sawed at existing joint lines to a point 1/2 in. (13 mm) below the
prepared cavity surface to hold new bond-breaking medium in place during concrete
A bond-breaking medium is required to maintain existing joints and working cracks.
Width of the medium shall be equal to the width of the existing gap at the joint or crack
and should extend at least 1 in. (25 mm) on each side of the prepared cavity. Depth of
the medium shall be not less than the depth of new patch materials. The medium
should be neatly installed to prevent new grout or concrete from by-passing the
medium and entering the joint space.