Item 257 Diamond Grinding Portland Cement Concrete Pavement
257.01
Description
257.02
Equipment
257.03
Construction
257.04 Final
Surface Finish
257.05 Method
of Measurement
257.06 Basis of
Payment
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 the equipment is capable of 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 it 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
(Square
Meter)
Concrete Pavement