DelDOT Section 503: Patching Portland Cement…

503.1Description.

This work consists of patching existing PCC pavement with high early strength concrete.

503.2Materials.

A.PCC, Class Rapid-set Section 1022

B.Liquid Membrane-Forming Compounds for Curing Section 1045.7

C.Joint Sealants Section 1042.1.B

D.Concrete Adhesive Section 1024.5

E.Wax-Based Bond Breaker with a Flash Point not less than 200 Degrees F

F.Embedded Hardware:

1.Tie Bars Section 1037

2.Dowel Bars Section 1037

3.Tie Bolts – Hook Bolts or W-Bolts Section 1037

503.3Construction.

A.Provide a flatwork technician with an ACI or NRMCA certification or a certification from a program

pre-approved by the Department to supervise all finishing. Provide the flatwork certification to the engineer before placing concrete. 503.3.1 Patching Limits.

A.The contract or the engineer will designate pavement for patching. The engineer will paint the

patching limits on the existing pavement.

B.The Department will designate patches as either Type A or Type B. A Type A patch is 15-feet or

less in length. A Type B patch is greater than 15-feet and less than 100-feet in length and contains load transfer assemblies consisting of dowel support baskets and dowel bars spaced at a maximum of 15-feet.

C.Construct pavement replacement greater than 100-feet in length under Section 501.

D.Patch limits in the direction of traffic shall either match or be offset by at least 2-feet from the

existing concrete pavement joints, any cracks, or patch ends in the immediate adjacent lanes.

E.Submit requests to change patch limits due to poor existing concrete conditions at proposed tie-in

locations at least 5-days before removal. The engineer will determine all patching limits

F.Ensure that the patches are at least the depth of the existing slab.

503.3.2 Saw Cutting.

A.Refer to and comply with all requirements listed in Section 762. Construct perimeter cuts plumb

and parallel to the roadway centerline. Minimize and seal over-cuts into the remaining slabs as directed by the engineer. Cut existing steel across the patch perimeter. Cut concrete no more than 2-days before removals. Remove and dispose of concrete slurry from saw cutting in accordance

with Section 106.8. Clean all travel lanes to the satisfaction of the engineer before opening to traffic following the saw cutting operation. 503.3.3 Patch Removal.

A.Remove the patch and any remaining bituminous overlay in the patch area by the lift-out

technique without damaging the remaining concrete slabs or disturbing the base and subgrade. The lift-out technique entails drilling holes into the patch to insert lifting hooks, pins, or chains. Repair damage to the remaining concrete slabs or the base and subgrade caused by improper patch removal using methods approved by the engineer.

B.When the lift-out technique is not feasible, break and remove the concrete in the patch area using

an approved mechanical pavement breaker or jackhammer. Remove the existing patch material with minimal disturbance to the remaining concrete or foundation.

C.Where the patch is next to the shoulder and removal of the concrete results in a clean, uniform

shoulder edge, the engineer may allow the contractor to use the shoulder edge as the form for the new concrete. If the shoulder is not designated for replacement, repair all areas of the shoulder pavement structure removed or disturbed by the patching operation. If the bituminous shoulder is damaged during concrete removal, place a side form to provide a vertical edge for the concrete patch. 503.3.4 Patch Preparation.

A.If the base material appears unsuitable or washed out after removing the concrete, remove the

unsuitable material to a maximum depth of 6-inches, or less as directed by the engineer. Fill the excavated area with concrete when placing the patch. Clean out the repair area with hand tools and protect the patch subgrade from water intrusion. Excessive moisture remaining after excavation may require construction of a pipe underdrain system as directed by the engineer or as shown in the contract.

B.In areas of composite pavements consisting of bituminous concrete over PCC pavement, the

contractor may pour the concrete patch flush with existing bituminous concrete pavement to eliminate grade differential. Place the additional concrete depth, not to exceed 6-inches, as directed by the engineer.

C.Pay particular attention to existing longitudinal joint areas where loose concrete may have

cracked away from the plumb line during patch removal. Clean all vertical faces before placing concrete.

D.Just before placing the concrete patch, spray a coating of wax-based bond breaker on the

longitudinal and transverse vertical faces of existing concrete pavement adjacent to the patch. 503.3.5 Dowel and Tie Bar Installation.

A.Provide and install dowel support baskets and dowel bars conforming to the requirements of the

contract for internal crack control joints at Type B patches. Cut the shipping or tie wires on the dowel bar support basket after placement within the proposed pavement box.

B.Equipment.

Use a drill support system to maintain proper hole alignment. Use gang drills on contracts requiring multiple patches. Saw out all damaged pavement adjacent to the patch if damaged by the drilling operation and replace the damaged sections.

C.Placement.

1.Place dowel bars in accordance with the Standard Construction Details. Tie bars are to be

provided and installed for Type B patches that are placed adjacent to concrete. Do not install tie bars on Type A patches.

2.Drill dowel bar and tie bar holes parallel to the pavement profile to a depth of half the dowl bar

or tie bar length. Align the dowel bars and tie bars to not exceed the tolerances indicated in the contract. Drill holes 1/8-inch greater than the dowel bar or tie bar diameter or as recommended by the manufacturer. Use a wire brush of appropriate size to clean the hole and then blow the hole with compressed air that is dry and oil free at a continuous pressure of at least 100 pounds per square inch, measured at the source. Place concrete adhesive using a nozzle or wand that will deposit the material to the back of the hole. Do not push or pour the anchoring materials into the holes. Install the dowel bar or tie bar using a twisting motion to completely coat the dowel or tie bar surface. Place a grout retainer ring at the interface of the concrete and dowel bar or tie bar. Support the dowel bars and tie bars in proper alignment until the concrete adhesive has cured. 503.3.6 Placing Concrete.

A.Wet the base course just before placing concrete. The water application rate should not cause any

pooling on the grade.

B.Place patching concrete directly on the moist subgrade and uniformly distribute and spread it over

the entire patch area. Place the concrete in each patch area in a continuous operation. Consolidate the concrete using a standard spud-type vibrator capable of visibly affecting the concrete a distance of 1-foot from the vibrator head. Insert the vibrator vertically into the concrete without dragging it through the mix.

C.Place the concrete when the ambient air temperature is at least 35 degrees F and rising, unless

otherwise allowed by the engineer.

D.Do not place plastic concrete if the temperature reaches 95 degrees F, unless otherwise allowed

by the engineer.

E.Before placing adjoining concrete paving lanes or shoulders, seal the previously sawed joint

opening along the edges of the existing concrete using duct tape, caulk, or other approved material to prevent stones or grout from entering the saw cut. 503.3.7 Concrete Strength Requirements.

A.To accomplish the designed compressive strength in 6-hours, establish the actual combination of

weights and proportion of admixtures as required due to field conditions, ambient temperature, humidity, and wind conditions. If unfavorable weather conditions prevent the concrete from reaching the desired strength in 6 hours, reschedule the patching work subject to approval by the engineer. The Department may consider the concrete defective if it fails to meet the compressive strength within 6-hours.

B.Remove and replace concrete the engineer determines to be structurally inadequate. The

Department will allow concrete determined to be structurally adequate by the engineer, but not meeting 2,000 pounds per square inch in 6-hours, to remain in place at a prorated payment in accordance with Section 503.5.1. If the contractor does not want to accept the prorated payment, the contractor may remove and replace the concrete in an attempt to achieve full compensation.

503.3.8 Finishing Concrete.

A.Strike off the concrete surface flush with the existing pavement. For patches up to 10 feet long,

place the screed parallel to the centerline of the roadway. For longer patches, the contractor may place the screed perpendicular to the centerline of the roadway.

B.Provide a tined finish on the concrete patch with the texture applied in a direction perpendicular

to the traffic flow when a bituminous concrete overly will cover the patch surface. Match the adjacent pavement surface cross slope and profile. The Department will consider the patch unacceptable if the profile in the finished patch area contains excessive surface deviations. The maximum allowable longitudinal and transverse deviation is 1/4-inch in 10-feet. Provide a 10-foot straight edge for testing. When the concrete patch is the final roadway surface, match the texture of the adjacent pavement. Match the patch surface cross section with the preceding and following pavement surfaces. The Department will not allow use of steel trowels for finishing surfaces. The engineer may test for excessive surface deviations with a straightedge, a profilometer, or other surface measuring device.

C.Repair damaged concrete or the bituminous shoulder before opening the patch area to traffic.

503.3.9 Curing.

A.Use one of the methods listed below:

1.White Membrane Curing Compound

a.Spray the curing material on the pavement surface and all exposed edges immediately

following concrete texturing.

b.Continuously agitate the curing material during application to keep it thoroughly mixed.

2.Polyethylene Sheeting

Place polyethylene sheeting over the concrete and beyond the slab edges a distance that equals double the pavement thickness. Add weight to secure the material against wind and weather.

3.Insulating Blankets

Secure edges and seams of insulating blankets to prevent dislodging due to wind, rain, or adjoining traffic. Use insulating blankets in accordance with Section 610.3.5.C.6. 503.3.10 Joints.

A.Install in accordance with the Standard Construction Details.

B.Clean and seal all joints with hot-poured sealant material after the specified strength has been

achieved, if no overlay is planned in accordance with Section 504.

C.Form or saw transverse and longitudinal joints as shown in the contract. Saw transverse joints in

Type B patches matching existing within the patch area in accordance with Section 501.3.9. Clean and seal the joints around the entire patch perimeter, and all transverse joints in larger patches, with hot-poured sealant material within 5 days after concrete placement, if no overlay is planned. Refer to and comply with all Section 504 requirements.

D.If the pavement will receive an overlay, the contractor may tool the transverse joints at the ends

of the patch. The Department will not require a sealant reservoir in this case. Widen and seal the sawed transverse joints for crack control within Type B patches for both finished surface and overlay conditions.

503.3.11 Performance Measures. Repair or remove and replace uncontrolled random cracks before Final Acceptance and payment. Submit repair or replacement procedures to the engineer for approval.

503.4Method of Measurement.

A.Patching PCC Pavement, 6 feet to 15 feet, Type A and Patching PCC Pavement Greater than 15

feet to 100 feet, Type B.

1.The Department will measure concrete patches placed and accepted by the square yard. The

Department will measure the width from outside of the completed patches as constructed and will measure parallel to the transverse saw cuts. The Department will measure parallel to the centerline of the pavement, along the center of the patch. The Department will not measure additional patch areas made necessary due to improper concrete removal or saw cutting.

B.Undercut Excavation, Patching.

1.The Department will measure material removed below the bottom of the original concrete

pavement the contractor patched by the cubic yard. Refer to Section 202.3.7.

C.Patching PCC Pavement, Undercutting.

1.The Department will measure concrete placed in undercut areas below the bottom of the

original pavement requiring the patch, or additional thickness above in order to eliminate grade differential in finished pavements by the square yard-inch.

D.Saw Cutting.

1.Refer to Section 762 for the method of measurement.

E.Dowel Bars.

1.The Department will measure the dowel bars installed and accepted at the ends of a patch as

each. The Department will not measure dowel bars and dowel support baskets (load transfer assemblies) installed at internal crack control joints in Type B patches. The Department will consider dowel bars and dowel support baskets installed at internal crack control joints in Type B patches as incidental to the contract unit price per square yard for item 503002 – Patching PCC Pavement, Greater Than 15 feet to 100 feet, Type B.

F.Crack and Joint Sealing Less than 3/4-Inch Wide.

1.Refer to Section 504 for crack and joint sealing methods of measurement.

G.Tie Bars.

1.The Department will not measure tie bars placed in Type B patches.

2.Do not place tie bars in Type A patches.

503.5Basis of Payment.

A.If the contract calls for replacing a bituminous overlay, the Department will pay for the overlay

using the applicable bituminous concrete pay item.

B.Type A Patches.

1.Square yard payment will constitute full compensation for:

a.Providing, placing, finishing, texturing, and curing concrete;

b.sealing sawed joints along the completed pavement edge to prevent stone or grout from

adjoining pours from entering the saw cut before placing adjoining pavement;

c.Sure-Cure test molds and curing materials;

d.removing and disposing of existing concrete and any bituminous overlay remaining on the

patch area at the time of removal;

e.preparing the foundation;

f.tooling, finishing, curing, texturing, sealing of over-cuts in non-overlay areas, and protecting

the new concrete; and

g.disposing of excess material resulting from necessary undercutting.

C.Type B Patches.

1.The square yard payment includes everything listed under basis of payment for Type A patches

and the following:

a.Providing and installing load transfer assemblies consisting of dowel bars and dowel support

baskets at all transverse joint locations except at either end of the patch;

b.providing and installing tie bars in accordance with the Standard Construction Details; and

c.transverse saw cutting and sealing in accordance with the Standard Construction Details.

D.Patching PCC Pavement (Undercutting).

1.The square yard-inch payment includes providing and placing concrete to depths not to exceed

6-inches resulting from the undercut excavation, patching item, or to eliminate the grade differential of finished pavements.

F.Dowel Bars.

1.Payment for each dowel bar includes:

a.Drilling the dowel holes;

b.providing and placing dowel bars;

c.anchoring grout;

d.grouting retainer disks; and

e.providing and placing temporary dowel supports to maintain alignment.

E.Saw Cutting Concrete, Full Depth.

1.The Department will pay this item separately in accordance with Section 762.

2.The Department will consider the following as incidental to the item of work and will make no

separate payment for this work:

a.Cutting existing bituminous overlays up to 8-inches thick over the concrete unless otherwise

noted in the contract;

b.cutting existing steel across the patch perimeter; and

c.additional cuts to facilitate patch removal.

F.The Department will pay for:

1.Undercut Excavation, Patching with Section 202.

2.Crack and Joint Sealing Less Than 3/4-Inch Wide with Section 504.

503.5.1 Price Adjustment for Low Strength Concrete. The Department will calculate the prorated payment for concrete, as referenced in Section 503.3.7, as shown in the following equation:

ITEM DESCRIPTION UNIT 503001 PATCHING PCC PAVEMENT, 6’ TO 15’, TYPE A SY 503002 PATCHING PCC PAVEMENT, 15’ TO 100’, TYPE B SY 503004 PATCHING PCC PAVEMENT (UNDERCUTTING) SY-IN 503006 DOWEL BARS EA

Referenced in this section

Sections that cite this one

PATCHING PORTLAND CEMENT CONCRETE PAVEMENT in other states

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Source: Delaware Standard Specifications for Road and Bridge Construction, 2026 Edition. Pages 160–0 of 786. View official source ↗

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501 PORTLAND CEMENT CONCRETE PAVEMENT

504 PCC CRACK AND JOINT SEALING

503PATCHING PORTLAND CEMENT CONCRETE PAVEMENT

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