Specifications include, but are not limited to: PCC PAVEMENT GRINDING, ASPHALT CONCRETE SURFACING OF SHOULDERS; A. GRINDING 1. Equipment: Grinding of PCC pavement will be accomplished using diamond blades mounted on a self-propelled machine designed specifically for diamond grinding and texturing pavement. The equipment will weigh a minimum of 35,000 pounds including the grinding head and be of a size that will grind a strip at least 4 feet wide in a single pass. The effective wheel base of the machine will be no less than 12 feet. The effective wheel base is defined as the distance from the front wheel assembly transverse pivot point to the transverse pivot point of the profile/depth control/ground drive wheels. The equipment will be such that it will not strain or damage the underlying pavement surface. Grinding equipment that causes raveling, aggregate fractures, spalls, or disturbance of the transverse or longitudinal joints will not be permitted. The equipment will have a positive means of vacuuming the grinding residue from the pavement surface, leaving the surface in a clean, near-dry condition. 2. Methods and Procedures: The grinding will be performed in a longitudinal direction. Grinding will begin and end at lines normal to the pavement centerline at the project limits. Passes of the grinding head will not overlap more than 1 inch. No unground surface area between passes will be permitted. The area ground between passes will not be left smooth or polished. Adequate cross slope drainage will be maintained. Lateral drainage will be achieved by maintaining a constant cross slope between grinding extremities in each lane. The finished cross slope will match the pre-grind cross slope. Structures will not be ground. 3. Final Surface Finish: The grinding process will produce a pavement surface true in grade and uniform in appearance with longitudinal line-type texture. The line-type texture will contain corrugations parallel to the centerline and present a narrow ridge corduroy type appearance. The area ground will not be left smooth or polished. The peaks of the ridges will be 1/8 inch ± 1/16 inch higher than the bottom of the grooves with evenly spaced ridges. The Engineer may require removal of unbroken fins at the Contractor’s expense. It is the Contractor’s responsibility to select the number of blades per foot to be used to provide the proper surface finish for the aggregate type and concrete present on the project. The number of blades used for grinding will range between 50 and 60 blades per foot as necessary to provide the designated texture. Harder aggregates may require the use of 55 to 60 blades per foot. The Contractor may be required to make multiple passes with the equipment to meet the specifications. It is the Contractor’s responsibility to determine the proper sequence of operations to meet the specifications. If multiple passes of the grinding equipment are required, the area will only be considered for payment once.
