Section 2310. Portland Cement Concrete Overlay

 

2310.01 description.

Overlay an existing pavement with one of the following types of PCC overlay:

 

A. Bonded overlay: a PCC overlay over an existing PCC pavement.

 

B. Unbonded overlay: a PCC overlay over an existing pavement where a stress relief layer is placed on top of the existing PCC pavement or a PCC overlay over an existing composite pavement (flexible pavement over PCC).

 

C. Whitetopping: a PCC overlay over an existing, full depth flexible pavement.

 

2310.02 materials.

 

A. Concrete.

Meet the requirements of Article 2301.02.

 

1. Use Class C concrete for PCC Overlays as specified in Materials I.M. 529, except use a C-3WR or C-4WR mix design for Bonded Overlays. Allowable substitutions shall comply with Article 2301.02, B.

 

2. For coarse aggregate, meet the requirements of Section 4109.02, Aggregate Gradation Table, Gradation No. 3 or 5 of the Appendix. Ensure the nominal maximum coarse aggregate size is no greater than one-third the overlay thickness.

 

3. Unless otherwise specified, use coarse aggregate for bonded overlays that is the same type of aggregate as the existing pavement.

 

B.  Hot Mix Asphalt Stress Relief Course.

 

1. Use an HMA stress relief course for unbonded overlays consisting of a nominal 1 inch (25 mm) course of HMA meeting the requirements of Section 2303.

 

2. Use PG 58-28 asphalt binder.

 

3. Use a mixture meeting the following:

a. 300,000 ESAL, 3/8 inch (9.5 mm) HMA mix requirements.

b. Target air voids of 3.0%.

c. No maximum film thickness restriction and no minimum filler/bitumen ratio restriction.

d. Type B Aggregate with no percent crushed particle requirements and gradation falling below the restricted zone.

 

C. Seal Coat Bond Breaker.

Meet the requirements of Article 2307.02.

 

2310.03 construction.

Apply the requirements of Section 2301 to this work with the modifications identified below.

 

A. Scarifying, Shotblasting, or Waterblasting Equipment.

Use power operated equipment capable of uniformly scarifying or removing the existing surface in a satisfactory manner and to depths required. Other types of removal devices may be used if their operation is suitable and if they can be demonstrated to the satisfaction of the Engineer. The contract documents will include a pay item for such work.

 

B. Preparation of Surface.

 

1. General.

a. If full depth base repair is included in the project, complete it prior to preparation of the existing pavement surface.

b. When required, include the entire area to be resurfaced in preparation of the existing pavement surface. Materials removed in the preparation operation may be placed in the shoulder area unless specified otherwise in the contract documents.

 

2. Surface Preparation.

a. When required for bonded overlays, prepare the surface by shot blasting, waterblasting, or scarifying. Scarify to a nominal depth of 1/4 inch (5 mm).

b. Ensure preparation removes all dirt, oil, foreign materials, laitance, or loose material from the surface and edges against which new concrete will be placed.

 

3. Pavement Scarification.

a. When required, prepare surface by scarifying per Section 2214.

b. At the direction of the Engineer, trim high spots found in the existing flexible pavement. This work will be accomplished during the scarification operation, only at isolated locations, and will be considered incidental to the pavement scarification.

c. Seal Coat Bond Breaker.

Prior to placement of the PCC overlay, place two applications of a seal coat bond breaker to scarified PCC surfaces per Article 2307.03 and as modified per Article 2316.03, B, 2, b. Do not allow traffic on bond breaker before it has set.

 

4. Hot Mix Asphalt Stress Relief Course.

Construct in accordance with Article 2303.03. Use Class II Compaction, except use only static steel wheeled rollers. Article 2303.04 shall also apply.

 

C. Placing and Finishing Overlay.

 

1. General.

a. Apply Section 2317 to all PCC Pavement bid items of a Primary project if any individual PCC Pavement bid item for that project is 5000 square yards (4200 m2) or greater. Apply Section 2316 to all other Primary projects and when specifically required for other projects.

b. Clean existing surface of loose or adhering foreign material prior to and during placement of PCC.

c. Ensure existing pavement surface is free of standing water during PCC placement.

d. Ensure temperature of existing pavement surface does not exceed 120F (50C) during PCC placement. Water may be applied to cool existing pavement surface provided standing water is not present during PCC placement.

 

2. Joints.

a. Unbonded Overlays and Whitetopping.

Place joints as shown in the contract documents.

b. Bonded Overlays.

1) Place joints directly over joints and cracks in the existing pavement.

2) Saw joints to the full depth of the overlay.

3) Ensure joints are at least as wide as the joint or crack in the existing pavement.

 

D. Limitation of Operations.

 

1. At forecasted air temperatures below 55F (13C) use the maturity method to determine the opening time. Do not place resurfacing concrete when the air or pavement temperature is below 40F (4C).

 

2. The Contractor may use the shoulders for construction activities. It will be the Contractor's responsibility to repair the shoulders, as the Engineer deems necessary, to restore the shoulders to a condition acceptable for shoulder work. This work shall be done at no additional cost to the Contracting Authority. The Contractor may elect to limit the use and vehicle loadings to minimize this work and its cost.

 

3. Place bonded concrete overlays between June 1 and September 30.

 

2310.04 method of measurement.

Measurement for the various items of work involved in the construction of PCC overlay will be as follows:

 

A. Portland Cement Concrete Overlay, Furnish Only.

Cubic yards (cubic meters) using a count of batches incorporated. Includes concrete placed in widening sections and partial depth patches.

 

B. Portland Cement Concrete Overlay, Placement Only.

Square yards (square meters) shown in the contract documents. Area will be determined from the longitudinal surface and the nominal pavement width, including widening sections.

 

C. Surface Preparation.

Square yards (square meters) shown in the contract documents. Area will be determined from the longitudinal surface and the nominal width of existing pavement.

 

D. Pavement Scarification

 

1. Measurement by Weight (Mass).

The quantity of Pavement Scarification will be determined in accordance with Article 2214.04, A, 1.

 

2. Measurement by Area.

The quantity of Pavement Scarification will be determined in accordance with Article 2214.04, A, 2.

 

E. Hot Mix Asphalt Stress Relief Course.

 

1. Measurement by Weight (Mass).

a. HMA will be measured according to Article 2303.04, A.

b. Asphalt binder will be measured according to Article 2303.04, B.

 

2. Measurement by Area.

a. HMA will be measured according to Article 2303,04, A, 2.

b. Asphalt binder used will not be measured separately for payment.

 

F. Seal Coat Bond Breaker.

 

1.     Aggregate.

Cover aggregate will be measured according to Article 2307.04, A.

 

2.     Binder Bitumen.

Binder Bitumen will be measured according to Article 2307.04, B.

 

2310.05 basis of payment.

Payment will be at the contract unit price as follows for the performance of acceptable work, measured as provided above.

 

A. Portland Cement Concrete Overlay, Furnish Only.

 

1. Per cubic yard (cubic meters).

 

2. Payment is full compensation for furnishing raw materials, proportioning, mixing, and delivery of concrete to the paving machine.

 

B. Portland Cement Concrete Overlay, Placement Only.

 

1. Per square yard (square meter).

 

2. Payment is full compensation for:

a. Furnishing all materials, labor, and equipment necessary to place, finish, texture, and cure the concrete.

b. Placement of tie bars for widening, if required.

c. Sawing, cleaning, and sealing the joints, if required.

d. Surface cleaning.

 

C. Surface Preparation.

 

1. Per square yard (square meter).

 

2. Payment is full compensation for preparation of the existing pavement, scarifying or shot blasting, and for removal of the existing pavement surface material according to Article 1104.08.

 

D. Pavement Scarification

 

1. Measurement by Weight (Mass).

The Contractor will be paid the contract unit price for Pavement Scarification in accordance with Article 2214.05, A, 1.

 

2. Measurement by Area.

The Contractor will be paid the contract unit price for Pavement Scarification in accordance with Article 2214.05, A, 2.

 

E. Hot Mix Asphalt Stress Relief Course.

 

1. Measurement by Weight (Mass).

a. Article 2303.05 applies.

b. Payment is full compensation for furnishing and placing the HMA stress relief course.

c. Asphalt binder will be paid for separately according to Article 2303.05, B.

 

2. Measurement by Area.

a. Article 2303.05 applies. 

b. Payment is full compensation for furnishing and placing the HMA stress relief course, including the cost of the asphalt binder.

 

F. Seal Coat Bond Breaker.

 

1. Aggregate.

Payment for cover aggregate will be in accordance with Article 2307.05, A.

 

2. Binder Bitumen.

Payment for binder bitumen will be in accordance with Article 2307.05, B.