2532 Pavement Surface Repair (Diamond Grinding)

Section 2532. Pavement Surface Repair (Diamond Grinding).

2532.01 DESCRIPTION.
This work involves grinding an existing PCC pavement surface for profile improvement, for use as a traffic surface, using a diamond grinder. Grinding and texturing shall be performed at the locations shown in the contract documents except for bridge decks, in which case the complete deck shall be ground according to Article 2532.03, B.

The existing surface and the coarse aggregate will be described in the contract documents.

2532.02 EQUIPMENT.
Grinding and texturing shall be done utilizing diamond blades, mounted on a self propelled machine that has been designed for grinding and texturing of concrete surfaces. The equipment shall be such that it will not cause strain or damage to the underlying pavement or bridge deck. Grinding and texturing equipment that causes excessive ravels, aggregate fractures, spalls, or disturbance of the transverse and/or longitudinal joints will not be permitted.

Grinding shall not extend across bridges unless specifically designated.

2532.03 CONSTRUCTION.
Pavement surface repair (diamond grinding) shall consist of grinding and texturing the entire surface of the pavement in a longitudinal direction.

Both the land area and the texture depth shall be within the specified ranges to be in compliance. It may be necessary to adjust the blade spacing during the project to stay within specified ranges.

For multiple passes, the equipment shall be carefully controlled to minimize the overlap. Overlaps shall not exceed 1 inch (25 mm).

The transverse slope of the ground concrete surface shall be uniform to a degree that there are no depressions or misalignment of slope greater than 1/4 inch in 12 feet (6 mm in 3.6 m) when tested by stringline or straightedge placed perpendicular to the center line.

In order to match the outside edge of the pavement, adjacent paved areas (for example, shoulders, curb and gutter, turn lanes, tapers, paved crossovers, and so forth) shall be ground to minimize vertical projections.

The Contractor shall be responsible for quality control of the texture. The Engineer will conduct random Quality Assurance inspections.

A. PCC Pavement.
Substantially the entire surface area of the pavement shall be ground and textured until the pavement surface on both sides of the transverse joints and all cracks are in the same plane and meet the smoothness required. In each lane, at least 95% of the area in each 100 foot (30 m) section shall have a newly ground surface.

Grinding shall be performed in a longitudinal direction. All construction traffic entering or leaving the work area shall move in the direction of traffic of the open lane. Grinding shall begin and end at lines normal to the pavement center line within any one ground area and at the project limits. This will not be required at the end of each shift. Good transverse drainage shall be maintained at all times.

The grinding head should be assembled to produce the following tolerances on pavements with the indicated coarse aggregates:

(ENGLISH) Limestone Gravel

Blade segment thickness
Land area between grooves* 0.130" maximum
0.100" to 0.135" 0.130" maximum
0.080" to 0.110"

Texture depth**
Target of 1/16" with average between 1/32" to 3/32"

(METRIC) Limestone Gravel

Blade segment thickness
Land area between grooves* 3.30 mm maximum
2.5 mm to 3.4 mm 3.30 mm maximum
2 mm to 2.75 mm

Texture depth** Target of 2 mm with average between 1 mm to 2.5 mm

* Based on an average of a minimum of ten measurements across the ground width for one pass.
** Based on an average of a minimum of six measurements across the ground width for one pass.

A test area 500 feet in length and the width of the grinding head will be allowed for each new or restacked head, provided a surface texture in reasonable conformance with the specification is being produced.

B. Bridge Deck
The entire surface of the bridge deck shall be ground and longitudinally grooved in accordance with Article 2412.06, A.

(ENGLISH) Limestone

Blade segment thickness
Land area between grooves* 0.130" maximum
0.100" to 0.125"

Texture depth** Target: 1/8" ą 1/32"

(METRIC) Limestone

Blade segment thickness
Land area between grooves* 3.30 mm maximum
2.5 mm to 3 mm

Texture depth** Target: 3 mm ą 1 mm

* Based on an average of a minimum of ten measurements across the ground width for one pass.
** Based on an average of a minimum of six measurements across the ground width for one pass.

2532.04 SMOOTHNESS.

A. PCC Pavement.
The pavement will be partly profiled on the initial trace by the Engineer using the procedure described in Article 2316.02. The average profile index for each area may be shown in the contract documents. The bidder is also advised that all profilograph information is available for inspection at the Office of Contracts, by a request to the Contracts Engineer. After the contract is awarded, the profilograph information will be available from the Engineer. This information represents a summary of conditions found to exist at the time the survey was made. The availability of this information will not constitute a guarantee that a profile other than that indicated will not be encountered at the time of grinding.

The Contractor shall provide a control profilograph trace as described in Article 2316.02 prior to performing any grinding work. This control trace will be used to identify the required smoothness for the project. Each segment of the finished ground surface shall have a final profile index of 10 inches per mile (160 mm/km)or less, and shall not include any bumps exceeding 0.5 inches in 25 feet (13 mm in 8 m). Prior to diamond grinding, the Contractor shall identify depressed pavement areas and localized areas with excess faulting greater than 1 inch (25 mm). The Contractor and Engineer shall review those areas to determine the limits for exclusion from the profile index calculation.

Profilograph testing shall end 15 feet (5 m) prior to excluded areas and shall resume 15 feet (5 m) following excluded areas.

The ground surface shall be tested and evaluated in accordance with Section 2316. Incentives for pavement smoothness will not apply.
B. Bridge Deck.
For bridge decks the smoothness requirements of Section 2428 shall be met prior to performing the texturing. After texturing, the bridge deck shall be tested again in accordance with Article 2428.03 and the resulting profile index shall not exceed the corrected profile index prior to the texturing.

2532.05 LIMITATIONS.

When nighttime work is required, lighting shall be included at each work area. Lighting shall not glare into oncoming motorists.

Removal of all slurry or residue resulting from the grinding operations shall be continuous and shall not be deposited on the slab or shoulder. Pavement and paved shoulders must be left in a clean condition. Residue from grinding operations shall not be permitted to flow across lanes occupied by public traffic or to flow into gutters or other drainage facilities. This residue may be spread on the foreslope or removed in accordance with Article 1104.08.

A. PCC Pavement.
Uncompleted sections may be opened to traffic without completion of grinding across an entire lane.

During nighttime operations, grinding shall progress in the direction with normal traffic in the lane being ground.

When the following work is included in the contract, the operations shall be sequenced in the following order:

1. undersealing
2. longitudinal subdrains
3. patching
4. installation of retrofit load transfer
5. diamond grinding
6. crack and joint sealing

B. Bridge Deck.
Work under this specifications shall be completed and smoothness requirements met prior to opening to traffic.

2532.06 METHOD OF MEASUREMENT.

A. PCC Pavement.
The quantity of pavement ground, in square yards (square meters), will be the quantity of Pavement Surface Repair, of the type specified, shown in the contract documents.

Adjacent paved areas ground to minimize vertical projections will not be measured for payment.

B. Bridge Deck.
The quantity of bridge deck ground and textured, in square yards (square meters), will be the quantity of Pavement Surface Repair, of the type specified, shown in the contract documents.

2532.07 BASIS OF PAYMENT.
For the number of square yards (square meters) of Pavement Surface Repair, (Grinding Limestone) or (Grinding Gravel), completed and measured as provided above, the Contractor will be paid the contract unit price per square yard (square meter). This payment shall be full compensation for furnishing all equipment, materials, and labor to grind the pavement and test for smoothness according to the contract documents, including removal of slurry and residue from this operation.

(ENGLISH)	Limestone	Gravel
Blade segment thickness Land area between grooves*	0.130" maximum 0.100" to 0.135"	0.130" maximum 0.080" to 0.110"
Texture depth**	Target of 1/16" with average between 1/32" to 3/32"

(METRIC)	Limestone	Gravel
Blade segment thickness Land area between grooves*	3.30 mm maximum 2.5 mm to 3.4 mm	3.30 mm maximum 2 mm to 2.75 mm
Texture depth**	Target of 2 mm with average between 1 mm to 2.5 mm
* Based on an average of a minimum of ten measurements across the ground width for one pass. ** Based on an average of a minimum of six measurements across the ground width for one pass.