Item 257 Diamond Grinding Portland Cement Concrete Pavement
257.01 Description. This work consists of diamond grinding and
texturing Portland cement concrete pavement longitudinally to substantially
eliminate joint and crack faulting and to restore proper riding characteristics
to the pavement surface.
257.02 Equipment. Provide grinding equipment that is a power
driven, self-propelled machine that is specifically designed to smooth and
texture Portland cement concrete pavement with diamond blades or diamond
impregnated cylinder rings. Mount the
blades or cylinder rings on an arbor head.
Provide a grinding head at least 3 feet (0.9 m) wide. Ensure the equipment is capable of grinding
the surface in the longitudinal direction without causing spalls
or other damage at cracks, joints and other locations. Ensure tThe equipment is
capable of l correcting the pavement profile and
providing proper cross slope on the concrete pavement.
Provide
equipment with an effective wheelbase of at least 12.0 feet (3.6 m); a
set of pivoting tandem bogey wheels at the front of the machine and rear wheels
that travel and track in the fresh cut pavement. Ensure the center of the grinding head is no
further than 3.0 feet (0.9 m) forward from the center of the back wheels. Ensure iIt
is
also of a shape and dimension that does not encroach on traffic movement
outside of the work area.
Furnish and
maintain a profiler conforming to Supplement
1058 for daily use during the grinding operations. Provide all necessary supplies to fully
operate and graph the results of testing the ground pavement for
smoothness. The Engineer will
verify the profiler according to Supplement
1058.
257.03 Construction. The plans will designate the areas of pavement
surfaces to be ground. Grinding of
bridge decks and roadway shoulders will not be required unless indicated on the
plans or required to provide drainage. Perform
grinding
in a manner that eliminates crack or joint faults while providing
positive lateral drainage by maintaining a constant cross-slope between
grinding extremities in each lane.
Transition auxiliary or ramp lane grinding as required from the mainline
edge to provide positive drainage and an acceptable riding surface.
Ensure the
operation results in pavement that conforms to the typical cross-section and
the requirements specified for the final surface finish, however, it is the
intention of this specification that the faulting at joints and cracks be eliminated and the overall riding characteristics be
restored within the limits specified. To
accomplish the smoothness required, grinding may not be required on 100 percent
of the pavement surface.
During
initial grinding operations, use the profiler to test the pavement surface as
soon as the concrete has been ground full lane width. This initial testing is to aid the Contractor in
evaluating the grinding methods and equipment being used. Subsequent to the initial testing, run daily
profiles of each day's grinding the next working day.
Remove all grinding residue. Remove solid residue before it is blown by
traffic action or wind. Do not allow
residue to flow across lanes used by the traveling public or into gutters or
drainage facilities.
257.04 Final Surface Finish. Produce a pavement surface that is true to
grade with the ground area consisting of a longitudinal corduroy-type
texture. Ensure the peaks of the ridges
are approximately 1/16 inch (1.5 mm) higher than the grooves with 53 to 57
evenly spaced grooves per foot (174 to 187 per meter).
Measure the
finished pavement surface for riding quality.
Produce a mainline riding surface which does not exceed an IRI of 95 inches per mile (1.50 m/km), nor any localized surface deviations in excess of 0.4 inches in 25 feet (10 mm in 7.6 m), as measured with the approved profiler. Use equipment conforming to Supplement 1058 and obtain a profile and smoothness measurements using ProVAL and supplement 1110. The Engineer will witness the testing of the pavement surface’s wheel paths. The wheel paths are located parallel to the centerline of the pavement and approximately 3 feet (0.9 m) measured transversely, inside all lane edges. Maintain the alignment of the profiler with reference to the pavement edge at all times. Re-grind any 0.10 mile (0.16 km) sections with an IRI greater than 95 inches per mile (1.5 m/km) until the measured IRI is less than 95 inches per mile (1.5 m/km).
Provide the
necessary traffic control and survey stationing for initial measurements or any
subsequent measurements. Measure the entire
length of pavement, starting and stopping the measuring equipment when any
wheel is within 1.0 foot (0.3 m) of any existing pavement, pressure relief
joint or approach slab.
Ensure
transverse joints and cracks are flush with adjacent surfaces. The Engineer will
visually inspect transverse joints and cracks to ensure that adjacent surfaces
are in the same plane. Adjacent sides of
joints or cracks within of 1/16 inch (1.5 mm) of each other will be
considered flush. Ensure the transverse
slope of the pavement is uniform to a degree that no depressions or
misalignments of slope greater 1/4 inch in 12 feet
(6 mm in 3.6 m) are present. Use a
straightedge placed perpendicular to the centerline to measure depressions and
misalignments.
Straightedge requirements do not apply outside of area ground.
257.05 Method of Measurement. The Department will measure diamond
grinding by the number of square yards
(square meters) of pavement ground and
accepted. The quantity of diamond
grinding will be determined by multiplying the width specified on the plan by
the total length of the finished pavement surface, excluding bridge decks,
approach slabs or the 1.0 foot (0.3 m) adjacent to the existing pavement,
pressure relief joints, approach slabs and other areas designated by the
Engineer.
257.06 Basis of Payment. Payment is full compensation for furnishing all labor, materials, tools,
equipment and incidentals and for doing all work involved in grinding the
existing surface, removing residue, cleaning the pavement, and testing with a
profiler.
The
Department will pay for accepted quantities at the contract price as follows:
Item unit Description
257 Square Yard Diamond grinding Portland cement concrete
(Square Meter) pavement