UFC 3-270-04
15 March 2001
harder the aggregate, the thinner the spacing between the blades. As the diamond grinding head
cuts the surface of the pavement, thin fins of concrete are left between the cutting blades. These
fins should break off during the grinding process. If these fins do not break off, a grinding head
with thinner spacers should be used. When grinding aggregate susceptible to polishing, the
spacing must be wider to provide more an area between the blades. The grinding chip thickness
measured at the thickest point should be an 0.080-inch (2-millimeter) minimum and have an
average thickness of 0.100 inch (2.5 millimeters). For harder aggregates not subject to polishing,
the minimum chip thickness should be 0.065 inch (1.7 millimeters) and an average of 0.080 inch
(2 millimeters).
9.5. Grinding Procedure. Roughness removal: When areas have been identified as being too
rough, a level of restoration must be set and sections having excess roughness must be ground.
Following the grinding, the roughness should be tested again. Testing is typically accomplished
using equipment such as the California Profilograph (Figure 9.3.) or the Mays Ride Meter. Prior
to grinding, the grade should be established. The old pavement surface should not be used as
the reference unless a long beam or skid is used. Where sags in the pavement are encountered,
the sags should be removed by slabjacking. Grinding a sag will not remove roughness. The
pavement should be reinvestigated following slabjacking to determine if grinding requirements
were altered.
Fault removal: Prior to grinding the faulted joints, the slabs should be undersealed to prevent the
fault from recurring. The joints must be cleaned, resawn to the proper depth, and resealed. This
is necessary to prevent infilration of water from the grinding operation. Grinding should cut into
the faulted joints, this produces smoother joints, and a more efficient operation. The fault must be
feathered back some distance into the slab. The distance required depends on the allowable
roughness. The American Concrete Paving Association has a general guideline of 1 foot
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