2529.03 FULL DEPTH PATCH THICKNESS.
Full depth patch thickness may be shown in the contract documents; if not shown, the thickness shall be as follows:

A. HMA Patches.
For Interstate and Primary pavement, the patch shall be the thickness of the HMA pavement, but not less than 9 inches (230 mm) or more than 15 inches (380 mm).

B. PCC Patches.
For PCC pavements on Interstate and Primary Roads the patch shall be the thickness of the pavement but not less than 9 inches (230 mm) or more than 12 inches (300 mm). For county roads the patch thickness shall be not less than 6 inches (150 mm) or more than 12 inches (300 mm).

C. Composite Patches.
For PCC pavements which have been resurfaced with HMA, the patch materials and thickness shall be the same as the existing pavement except the PCC portion of the patch shall not be less than 9 inches (230 mm) or more than 12 inches (300 m) unless otherwise specified in the contract documents. If the HMA resurfacing exceeds 4 1/2 inches (120 mm) (nominal) the patch shall be an HMA patch, unless otherwise specified in the contract documents.

2529.04 PAVEMENT REMOVAL.
Pavement removal for construction of full depth patches shall be in accordance with the following requirements:

When repairing PCC pavement, even though it may have been resurfaced, material shall be removed for the full pavement depth, unless otherwise designated. Excavation will be required for the patch thickness and, if required, for the granular subbase.

The contract documents will include an estimate of the number of anchor lugs to be removed. When an anchor lug is encountered within an area to be patched, the anchor lug shall be broken down to approximately 6 inches (150 mm) below the bottom of the pavement, all exposed anchor lug reinforcing shall be removed, and the concrete shall be replaced with granular subbase aggregate, compacted as required, to the elevation of the bottom of the patch.

Reinforcement shall be removed from the patch area, and to approximately 1 inch (25 mm) or less from the concrete that is to remain except for continuously reinforced pavements.

Unless otherwise shown in the contract documents, all patches will be full lane width. The length of each patch, measured parallel to the center line, will not be less than 6 feet (1.8 m) on Interstate pavements and 4 feet (1.2 m) on other pavements except continuously reinforced full depth finish patches. Continuously reinforced patches will not be less than 8 feet (2.4 m) in length.

All pavement removed shall be removed in accordance with Article 2510.02.

A. Full Depth HMA Finish Patches.
Except where an existing longitudinal or transverse joint forms an edge of the patch, the patch edge shall be constructed by sawing full depth of the patch; a saw, a concrete cutter, or other equipment that will result in a reasonably vertical edge shall be used. In HMA pavement patches a 15 inch (380 mm) deep severance will be considered full depth. After severance is made, a drop hammer, hydrohammer, or other heavy equipment may be used. This work shall be done in a way to not damage pavement that is to remain.

B. Full Depth PCC Finish Patches, With or Without Dowels.
This applies to PCC finish patches for jointed PCC pavement, including composite sections of resurfaced PCC pavement.

1. Patches With Dowels.
The edges of proposed patches shall be sawed full depth with a blade saw.

2. Patches Without Dowels.
The transverse edges of proposed patches shall be sawed to a depth of 1 1/2 inches (40 mm) with a blade saw. The pavement shall be severed by a full depth cut with a saw or concrete cutter approximately 1 1/2 inches (40 mm) inside the original 1 1/2 inches (40 mm) transverse saw cut. Edges at center lines and lane lines shall be sawed with a blade saw.

After severance is made, pavement in removal areas may be broken by use of a drop hammer, hydrohammer, or other heavy equipment. This work shall be done in a manner to not damage concrete that is to remain. Heavy equipment shall not be used adjacent to new concrete until the specified curing is completed.

Preparation of the patch edges shall be completed using equipment no heavier than a 15 pounds (7 kg) air chisel. A 30 pound (14 kg) air chisel may be used if its use does not result in significant undercutting of the pavement. The finished transverse edge is to be sawed to 1 1/2 inches (40 mm) as specified above. The ledge at the bottom of the 1 1/2 inches (40 mm) saw cut shall be removed to the bottom of the pavement at a uniform constant taper towards the patch interior. This removal shall be within 0 to 1 1/2 inches (0 mm to 40 mm) from vertical and shall have a roughened surface to promote interlock. Undercutting shall be avoided. If spalling at the top edge or undercutting continues, the Engineer may withdraw permission to use equipment heavier than a 15 pound (7 kg) air chisel.

C. Full Depth PCC Finish Patches, Continuously Reinforced.
This method applies to PCC finish patches for continuously reinforced PCC pavement, including composite sections of resurfaced PCC pavement, where the continuous reinforcement is to be restored.

The transverse edges of the patch shall be constructed with a blade saw to a nominal depth of 1 1/2 inches (40 mm), avoiding cutting longitudinal reinforcement. Edges at center lines and lane lines shall be sawed with a blade saw through existing tie bars.

Within the patch area, the pavement shall be severed transversely by a full depth cut with a blade saw inside the 1 1/2 inches (40 mm) saw cut to a depth through the existing reinforcing. This severance will be located so as to leave a minimum of 20 inches (500 mm) of longitudinal steel protruding into the patch area.

Breaking of pavement shall be done in such a manner as not to damage concrete that is to remain. Heavy equipment shall not be used adjacent to new concrete until the specified curing is completed.

Pavement between the 1 1/2 inches (40 mm) saw cut and the severance shall be removed with jackhammers or other hand equipment; however, the edge of the patch at the 1 1/2 (40 mm) inch saw cut shall be completed using equipment no heavier than a 15 pound (7 kg) air chisel. A 30 pound (14 kg) air chisel may be used if its use does not result in significant undercutting of the pavement. The shoulder at the bottom of the 1 1/2 inch (40 mm) saw cut shall be removed, and the edge below the saw cut shall be reasonably vertical, tapered to the interior of the patch, and shall have a rough surface to promote interlock. Work with the air chisel should continue until the taper at the bottom of the pavement is approximately within 0 to 1 1/2 inches (0 mm to 40 mm) from vertical. Undercutting shall be avoided. The saw cut shall be reconstructed, if necessary, so the top edge at the pavement surface is not frayed or spalled. If spalling at the top edge or undercutting continues, the Engineer may withdraw permission to use equipment heavier than a 15 pound (7 kg) air chisel.

Pavement shall be broken and removed in such a manner that protruding longitudinal steel is not unduly disturbed. Reasonable care shall be taken to preserve a 20 inch (500 mm) length of longitudinal steel. The steel shall not be bent more than the minimum necessary for concrete removal and subgrade or subbase compaction.

D. Full Depth Composite Patches.
When an existing PCC pavement has been resurfaced with 4 1/2 inches (120 mm) of HMA or less, the patch shall be constructed in accordance with Section 2212, PCC Full Depth Repair Patches and HMA Surface Patches to result in a composite patch, unless otherwise specified in the contract documents. The PCC area and edges of the patch shall be lightly tacked, and the hot mixture placed in the remaining depth and compacted, while hot, to provide a dense, smooth riding surface.

2529.05 RESTORING SUBBASE OR SUBGRADE FOR FULL DEPTH FINISH PATCHES.
When subbase is required by the contract documents or by the Engineer, the exposed subbase and/or subgrade shall be removed to a depth of 6 inches (150 mm) below the bottom of the new patch, and replaced with subbase. When unstable material or excessive moisture is encountered in the subgrade, the Engineer may order an additional thickness of subbase, if necessary, to assure drainage.

When the existing subgrade, base, or subbase is damaged during removal operations and subbase placement is not required, repairs shall be made at the Contractor's expense. Overdepth removal may be replaced with granular subbase material or the patching mixture. When the granular subbase material cannot be properly drained, the overdepth removal shall be replaced with the patching mixture.

Subbase material shall be placed with a field optimum moisture content established by the Engineer. It shall be placed in lifts not exceeding a nominal compacted thickness of 6 inches (150 mm). Compaction shall be by a minimum of four complete coverages with a vibratory compactor with additional coverages as are necessary to assure maximum consolidation. The compaction procedure for subbase normally will be established by the Engineer using the initial area as a trial section.

The exposed subgrade or subbase shall be compacted by a minimum of four complete coverages with a plate type vibratory compactor with a manufacturer's certified force rating of 6,000 pounds (26 kN).

2529.06 RESTORING REINFORCEMENT FOR PORTLAND CEMENT CONCRETE AND CONTINUOUSLY REINFORCED CONCRETE FINISH PATCHES.
Existing tie bars shall be cut off. Tie bars shall be replaced when required by the contract documents. New tie bars shall be placed in predrilled holes using epoxy grout, as provided in Article 2301.12. When there is a common line for patching, a bent bar may be placed in a keyway and later straightened.

A. PCC Finish Patches Without Dowels.
Restoration of reinforcement is not required, except for tie bars as described above.

B. PCC Finish Patches With Dowels.
When dowels and/or tie bars are required at the transverse edges of the patch, the contract documents will show details of the placement. Individual dowels or tie bars shall be placed in predrilled holes using epoxy grout, in accordance with Article 2301.12. The drilling alignment shall be controlled by a suitable jig designed for that purpose. The dowels extending into the patch area shall be coated with a bond breaker; reinforcing bars shall not be coated.

When CD joints are required, the contract documents will show details of the placement of dowel assemblies. These joints shall be located to meet joints or cracks in the adjacent lane. The dowel assemblies shall meet requirements of Article 4151.02, B. The dowel assemblies shall be placed and secured in proper position before the concrete is placed, in accordance with Article 2301.12.

C. PCC Finish Patches, Continuously Reinforced.
After the subbase, if required, is in place and compacted, new reinforcement shall be set. Protruding longitudinal reinforcement ends shall be made as true as practical and shall be cleaned of loose concrete and concrete which would interfere with close placement of new reinforcement.

Longitudinal reinforcement shall be restored using bars of the same grade, size, and spacing, as in the original pavement. The contract documents will describe the reinforcement in the existing pavement.

New longitudinal reinforcement shall be set to connect the longitudinal reinforcement across the repair area, lapping the protruding reinforcement at the same elevation and wire tied at least twice. Bars shall be furnished in appropriate lengths to minimize the number of splices. The maximum length of bars required shall be 20 feet (6 m).

2529.07 SUBDRAINS.
When subbase material and longitudinal subdrains are required by the contract documents or the Engineer, the subbase shall be placed as backfill to drain to the longitudinal subdrain.

2529.08 PLACING FULL DEPTH HOT MIX ASPHALT FINISH PATCHES.
After removal of the old pavement, the edges of the old pavement and the adjacent 1 foot (0.3 m) of subgrade shall be lightly tacked.

The HMA patch mixture shall be deposited in layers; the upper 5 inches (125 mm) shall be deposited in at least two layers, the top layer not exceeding 2 inches (50 mm) in thickness, when compacted. Lifts should be at least 3 times the mixture size. Each layer shall be thoroughly compacted, while hot, by rolling or compacting with a vibratory compactor to provide a dense compacted surface. Succeeding layers may be placed as soon as the preceding layer has been properly compacted. The final layer shall also be smoothed with a steel tired finish roller meeting requirements of Article 2001.05, B or F. A roller meeting requirements of Article 2001.05, F, may be a small roller suitable for this type of operation. The Engineer may require test cores for density and depth be taken, with no additional payment, to verify that the Contractor's construction method is satisfactory. This final compacted surface shall be level with, or not more than approximately 1/4 inch (5 mm) above the surrounding pavement surface. Patch material which extends beyond the edge of the pavement shall be cut off.

The patch shall not be opened to traffic until the mixture has cooled to provide stability, however, barricades on two lane highways shall not be left in place overnight. If the patch becomes distorted for any reason, the Contractor shall smooth the surface the next working day, by blading, scraping, filling, or by other approved means.

Prior to final acceptance, the patch shall be level with, or not more than 1/8 inch (3 mm) above, the adjacent pavement, and shall have a smooth riding surface.

2529.09 PLACING FULL DEPTH PORTLAND CEMENT CONCRETE FINISH PATCHES.
Forms shall be used on all exposed edges and also along the center line for patches that extend into an adjacent lane. Wood forms may be used in lieu of steel by using 2 inch (50 mm) nominal dimension lumber the full depth of concrete. Where old pavement has a curb, the forms shall extend from the bottom of the patch to the top of the curb. All wood forms shall be staked to hold the forms in place and in proper alignment.

Placing, consolidation, finishing, and curing of the concrete shall be as provided in Section 2301, except as follows:

The subbase or subgrade shall be moistened or covered with a single layer of plastic film meeting requirements of Section 4107.

Except for preplanned joints, placement shall be continuous until the patch is completed. When a delay of 45 minutes can not be avoided, an appropriate DW joint shall be constructed.

The concrete shall be dumped or conveyed into the patch areas to avoid segregation of the aggregates and cement, spread into place, vibrated with a mechanical vibrator, smoothed, and finished to the elevation of the adjacent PCC surface. Excessive vibrating shall be avoided. Full lane width patches over 25 feet (10 m) in length shall be finished flush with the adjacent pavement and with a finishing machine that has at least one vibrating screed. All patches finished flush with adjacent pavement shall be straight edged to ensure a smooth riding surface, and shall be textured by finishing with a burlap, carpet drag, or rake, to approximately match the texture of the adjacent surface. The patches shall be checked with a 10 foot (3 m) straightedge before the concrete has set, and spots that are 1/8 inch (3 mm) high or low, as shown by the straightedge, shall be corrected. The existing pavement crown must be maintained.

All edges and end of patches shall be finished with an edging tool.

The lane edges and end of patches shall have the edging constructed to a depth of approximately 1 1/8 inches (30 mm), leaving an opening of at least 3/8 inch (10 mm) to provide a reservoir for joint sealer. The reservoir may be constructed by hand methods or may be sawed. When white pigmented curing compound is used, the reservoir shall be protected with tape or other suitable material.

On patches finished flush with the pavement surface, the Contractor shall stamp two numerals indicating the year of placement 2 feet (0.6 m) from the outside edge, facing outward to be read from the near shoulder.

After the concrete has been finished and surface water has disappeared, the concrete shall be cured. Placement of curing materials shall occur no later than 20 minutes after completion of finishing operations. Concrete shall be cured by completely covering with an insulating blanket type cover. This cover shall consist of a layer of closed cell polystyrene foam protected by at least one layer of plastic film, rated by the manufacturer with a minimum R-value of 0.5 (0.08805 for metric units). The blanket-type cover shall be completely covered with insulation board. The board shall be cellulosic fiber sheathing with a nominal 3/4 inch (19 mm) thickness. The board may be wrapped with plastic film to protect it from rain. The board shall be placed over the patch and adjacent surface and held tightly in place with weights to retain all possible heat in the concrete.

PCC patches placed on multi-lane sections shall be cured a minimum of 10 hours before opening to traffic. PCC patches placed on two-lane sections shall be cured a minimum of 5 hours before opening to traffic. These restrictions may be modified in the plans or by the Engineer for specific situations.

Patches that are damaged in any manner during the curing period shall be replaced by the Contractor at no additional cost.

2529.10 SMOOTHNESS.
Section 2316 shall apply to smoothness of full depth finish patches except when the contract includes an overlay or pavement surface repair by diamond grinding or milling within the patch area and the following modifications:

A. Profilometer testing and evaluation is required for each patch with a length of 50 feet (15 m) or more. The testing shall be done after the patch is placed and near the center of the traffic lane. For each patch added by the Engineer that is greater than 50 feet (15 m) long, the Contractor will be paid $500 in addition to the appropriate unit prices involved. This is to compensate for additional smoothness requirements.

B. Patches 50 feet to 100 feet (15 m to 30 m) in length.

1. Test the patch length, and the existing pavement in that lane for a distance of three times the patch length on both ends of the patch. If a patch occurs near a bridge, intersection, etc., where the proper distance can not be tested, make up the required total on the other end of the patch. If interference occurs on both ends, test only to the points of interference.

Establish one Average Base Index (ABI) of the pavement for both ends of patch.

2. Calculate a new index for the entire length.

3. Compare the new index with the ABI.

a. If the new index does not exceed the ABI, the work is acceptable and no correction is required.

b. Corrective action is also not required if the new profilometer index is equal to or less than 12 inches per mile (190 mm/km), regardless of the ABI.

c. If the new profilometer index is greater than 12 inches per mile (190 mm/km) and less than 30 inches per mile (470 mm/km) and is also within 2 inches per mile (32 mm/km) of the ABI, corrective action is not required.

d. If the new profilometer index is greater than 30 inches per mile (470 mm/km), corrective action is required to reduce the new index at least to the ABI.

4. Corrective action shall involve correction of bumps and dips exceeding a vertical height of 0.5 inch (13 mm) in a 25 foot (7.6 m) span in the patch, if identified from the trace, plus appropriate surface correction within the patch and/or existing pavement on either end of the patch within the limits tested.

C. Patches 100 feet to 250 feet (30 m to 75 m) in length:

Paragraph B, above, applies, except the length tested shall be the patch length, and the existing pavement in that lane for a distance of 300 feet (90 m) on both ends of the patch.

D. Patches over 250 feet (75 m) in length:

Requirements for Chart B pavement, Section 2316 shall apply.

2529.11 AREA RESTORATION.
When the patch is completed, the forms shall be removed and the trench shall be backfilled. If a form is necessary on a longitudinal joint, the space between the patch and the adjacent traveled lane shall be temporarily filled with suitable material until the adjacent patch can be constructed. The excavated space along the outside pavement edge shall be filled with material similar to that in the existing shoulder and thoroughly compacted, as directed by the Engineer, before the section is opened to traffic.

2529.12 LIMITATION OF OPERATIONS.
All operations shall be conducted with minimum inconvenience to traffic. Traffic shall be maintained during construction operations unless the road is closed.

On two-lane roads, patching shall be conducted on only one lane at a time when traffic is maintained.

For roads with multiple lanes each direction, the work area may include one lane each direction or as allowed by the traffic control details. Where patching is required in adjacent lanes at the same location the median lane shall be completed first.

The Contractor shall place Stop Sign Rumble Strips, when included in the plans, prior to opening roadway sections to traffic.

When conditions permit, patch areas may extend up to 2 feet (0.6 m) into an adjacent lane. When this encroachment is not tabulated in the contract documents, it must be approved by the Engineer prior to beginning work. A flagger will be required at these locations. Work in an adjacent lane must be completed and opened to traffic the same day using PCC (Class A or B) or HMA to match the normal patch area material.

When HMA patches on two-lane roadways and PCC patches with calcium chloride are constructed, the work schedule shall be adjusted so all equipment and obstructions are removed from the travel lanes and shoulders from 30 minutes before sunset to 30 minutes after sunrise.

When PCC patches without calcium chloride are constructed, two drums meeting the requirements of Article 2528.03, B shall be placed in front of each patch location where there is a possibility of turning into or returning to the closed lane. Additional drums need not be placed for patches spaced closer than 150 feet (45 m).

If unforeseen difficulties should result in excavated areas being left overnight, a sufficient number of flaggers shall be assigned to warn and direct traffic until the areas are complete. No extra payment will be made for the necessary flaggers.

Full depth sawing shall be limited to patch areas scheduled to be constructed the following work day. The Engineer may limit advance sawing.

Pressure relief joints within patch areas shall not be reconstructed. When these joints extend into adjacent lanes, a full depth patch shall also be constructed in the adjacent lane as directed by the Engineer.

Joints and edge of PCC patches to be sealed may be cleaned and sealed as soon as the vertical surfaces appear dry by visual examination. Sealing shall be completed within 5 working days after the patch is placed. PCC patches to be covered by HMA shall be covered with HMA during the working day the curing is completed.

When other work is included in the contract, the operations in an area shall be sequenced in the following order: undersealing, longitudinal subdrains, patching, milling, installation of retrofit load transfer, crack and joint sealing.

If a DW joint becomes necessary, the area following the joint shall be filled with a suitable temporary hot or cold paving mixture or stable granular material, as directed by the Engineer.

2529.13 METHOD OF MEASUREMENT.
The Engineer will determine the quantities of the various items involved in satisfactory construction of full depth pavement patches as follows:

A. Full Depth Finish Patches.
The number of individual full depth finish patches will be determined by count. Patches in each traffic lane will be individually counted. Also, the areas of full depth finish patches will be computed in square yards (square meters) from measurements of the areas of pavement removed and replaced, except that each patch which is less than 2 square yards (2.0 m²) in area will be counted as 2 square yards (2.0 m²). The length will be measured parallel to the center line.

Areas associated with anchor lug removal will be included in these measurements.

Tie bars and dowel bars at the patch edges, when required, will not be measured for payment.

B. CD and CT Joints.

1. CD Joint Assembly
2. CT Joint

When CD Joint Assemblies or CT Joints are required within the patch area, the Engineer will count the number of joints properly installed of each type respectively. For CT Joints inadvertently missed or added during the construction process, the Engineer will count the number of joints properly installed. Each joint is for one lane width Partial lane width joints will be counted as one lane width for payment purposes.

C. Hot Mix Asphalt (Composite Section).
For composite sections, the Engineer will compute or estimate the number of tons (megagrams) of HMA placed on PCC surfaces for patches.

D. Subbase (Patches).
Where subbase aggregate is placed in patch areas, as required by the contract documents or the Engineer, the Engineer will compute in square yards (square meters) the areas of subbase placed as provided in Paragraph A, above, excluding areas associated with anchor lug removal. The Engineer will not measure subbase aggregate used for special shaping at longitudinal drains or subbase used at the Contractor's option.

The Engineer will separately compute areas in square yards (square meters), where subbase was directed to be placed to a depth greater than that originally specified.

E. Removal of Anchor Lugs.
The Engineer will count the number of anchor lugs removed in each traffic lane.

2529.14 BASIS OF PAYMENT.
For construction of the various items measured for pavement patches, the Contractor will be paid as follows:

A. Full Depth Finish Patches.
For the number of individual, full depth finish patches placed, the Contractor will be paid the contract unit price for each, and for the number of square yards (square meters) of full depth finish patches placed, the Contractor will also be paid the contract unit price per square yard (square meter).

1. Full Depth Finish Patches, by Count.
This payment shall be full compensation for all sawing or cutting necessary and for furnishing and installation of dowel bars at patch edges. The type or types of patches to be counted will be identified by the following types and tabulated in the contract documents.

a. Full Depth HMA Finish Patches.

b. Full Depth PCC Finish Patches, Without Dowels.

c. Full Depth PCC Finish Patches, Without Dowels, Composite Section.

d. Full Depth PCC Finish Patches, With Dowels.

e. Full Depth PCC Finish Patches, Composite Section.

f. Full Depth PCC Finish Patches, Continuously Reinforced.

g. Full Depth PCC Finish Patches, Continuously Reinforced, Composite Section.

2. Full Depth Finish Patches, by Area.
This payment shall be full compensation for removal of the old pavement, restoring the subgrade or subbase, furnishing and installation of tie bars, restoring longitudinal reinforcement for continuously reinforced patches, furnishing and placing the patching material, including the asphalt binder, tack coat, curing, joint sealing, and backfilling the disturbed area. When joint and crack sealing is included in the contract, joint sealing of the patches shall be accomplished and paid for as part of that work.

When the average thickness of the existing pavement at any one patch location varies from the thickness shown in the plans, the square yard (square meter) patching quantity will be adjusted per the following chart. Quantities will be increased when pavement thickness is greater than shown in the plans and decreased when less than shown in the plans.

% Change of Thickness	% Change of Quantity
0 to 10	0
> 10 to 20	10
> 20 to 30	15
>30	20

B. CD and CT Joints.

1. CD Joint Assembly
2. CT Joint

For the number of each type of joint furnished and placed, the Contractor will be paid the contract unit price per type of joint.

C. Hot Mix Asphalt (Composite Sections).
For the number of tons (megagrams) of HMA used for surfaces of patches with composite sections, the Contractor will be paid the contract unit price per ton (megagram). This payment also includes full compensation for the asphalt binder in the HMA mix.

D. Subbase (Patches).
For the number of square yards (square meters) of subbase furnished and placed, the Contractor will be paid the contract unit price per square yard (square meter). This payment shall be full compensation for furnishing and installing subbase, the additional excavation necessary for this placement and the removal of excavated material, the construction of transverse subdrains, and the backfilling of the disturbed shoulder area.

When subbase has been placed to a greater depth than specified in the contract documents, at the Engineer's direction, payment per square yard (square meter) for those areas will be increased by 20% for each inch (30 mm) of increased depth. This increased payment shall be full compensation for additional excavation and subbase material, associated compaction, and if so ordered, additional depth for the transverse subdrain.

E. Removal of Anchor Lugs.
For the number of anchor lugs removed in each traffic lane, the Contractor will be paid the contract unit price. This payment shall be full compensation for removal and for furnishing and placing subbase material, as specified. If removal of anchor lugs is not a bid item in the contract documents, the Contractor will be paid $600 per lane in which an anchor lug, or portion of anchor lug is removed.