2302.01 DESCRIPTION.
This work shall consist of widening existing pavement with PCC to provide a widened traffic surface in accordance with the contract documents and the following provisions. The appropriate provisions of Section 2301 shall apply to this work.

This work may also involve removal of curb, removal of flumes, and shoulder construction.

2302.02 MATERIALS.
Materials used shall meet requirements of appropriate sections of Division 41.

2302.03 CONCRETE.
Materials used shall meet requirements for Class A or Class C concrete in the current Materials I.M. 529.

2302.04 MAINTENANCE OF TRAFFIC.
Traffic shall be maintained through the project unless otherwise indicated in the contract documents.

2302.05 REMOVAL OF FLUMES.
Removal of flumes shall be in accordance with Section 2514.

2302.06 REMOVAL OF CURB.
Removal of curb shall be in accordance with Section 2514.

2302.07 PREPARATION OF SUBGRADE.
The width of trench cut for the widening shall be not less than 6 inches (150 mm) greater than the base width of the widening shown in the contract documents. If fixed forms are used, the width of trench shall accommodate the form. The subgrade shall be brought to an elevation and cross section such that, after being rolled, the surface will be at the required elevation. Depressions that develop during rolling shall be corrected, and the rolling shall be continued until the subgrade is uniformly firm, properly shaped, and true to grade and cross section. Material, other than sand, which will not compact readily under the roller shall be removed and replaced with material which will compact readily, and that portion of the subgrade shall be rolled again. The roller shall be adapted to conditions affecting the work and shall meet requirements of Article 2001.05. The weight (mass) of the roller may be reduced at the direction of the Engineer to the minimum required to provide a smooth, firm subgrade. While constructing subgrade, the soil shall be maintained in a condition sufficiently moist to facilitate compaction. The treatment of subgrade or subbase shall be in accordance with Article 2109.03. When plastic film is used, the width of the plastic shall not be less than the nominal width of the widening being constructed.

Ditches or drains shall be provided at frequent intervals to permit ready drainage to side ditches. For sections more than 800 feet (250 m) long, the subgrade shall be completed not less than 800 feet (250 m) in advance of PCC placement. The Contractor shall check the finished subgrade with a template supported on the surface of the adjacent pavement. The edge of the old pavement shall be cleaned.

2302.08 CONSTRUCTION OF PORTLAND CEMENT CONCRETE WIDENING.
PCC widening shall be constructed as follows:

A. Placing and Finishing.
After the subgrade has been prepared, the concrete shall be deposited directly on the subgrade without being dumped on the pavement.

Concrete may be placed and finished by use of fixed forms or slipform paver.

When a slipform paver is used, the consistency of the concrete and amount of vibration shall be controlled so that the full width and depth of the section is consolidated and no slump occurs after the sliding form has passed. The slipform paver shall be provided with a metal strike off plate not less than 3 feet (0.9 m) long and extending not more than 3 inches (75 mm) onto the surface of the pavement being widened. The sliding side form shall be made of metal. To assure alignment, it shall be provided with adjustable rigid braces at not more than 4 foot (1.2 m) intervals.

The concrete shall be consolidated by mechanical vibrators. A sufficient number of vibrators shall be provided to ensure adequate consolidation. Vibrators shall be operated at an appropriate frequency which shall be independent of the forward speed of the paver.

The concrete widening shall be finished flush with the adjacent pavement surface without either edging or sealing the joint. When voids occur in the edge of the old pavement wider than 1 1/2 inches (40 mm), measured at right angles to the pavement edge, they shall be filled with concrete, but shall be separated from the widening by preformed mastic dummy joint 1/8 inch thick by 2 inches wide (3 mm thick by 50 mm wide), installed directly over the edge of the old pavement. When checked, high spots in excess of 1/4 inch on a 10 foot (6 mm on a 3 m) straightedge shall be corrected. The surface of the new concrete shall have the texture produced by a burlap or carpet drag.

When the concrete widening intersects an approach road or driveway to a dwelling or business establishment, provisions shall be made for access as follows:

1. Widening shall be constructed only halfway through the roadway or driveway access on the initial construction, and a suitable approach shall be provided through the unpaved portion of the access. In not less than 4 working days nor more than 7 working days, gaps left open shall be filled. A removable header board, equipped with keyway in lieu of dowel bars, may be used at these locations.

2. A temporary bridge, approved by the Engineer, may be provided for access from driveways to dwellings or to business establishments permitting the widening to be constructed continuously across the driveways. At the Contractor's option, concrete used to widen the pavement at driveways to dwellings or to business establishments may have 2 pounds (2 kg) of calcium chloride (solid form) per 100 pounds (100 kg) of cement added at the mixer for the full length of mixing cycle. When calcium chloride is used, the temporary bridges may be removed after 24 hours when suitable approaches are provided for the driveway.

B. Contraction Joints.
Transverse contraction joints shall be constructed as shown in the contract documents. This work will be considered incidental and will not be paid for separately.

C. Protection and Curing.
The freshly finished concrete surface shall be protected and cured as provided in Article 2301.19.

Within 0.5 working day after placement of the concrete, earth check dams shall be constructed to prevent water from flowing along the edge of the pavement to the extent that the edge of the slab may be undermined. These check dams shall not be spaced or be of a width to provide an approach over which a vehicle may be driven onto the pavement.

2302.09 SHOULDERS.
Unless otherwise specified, shoulder construction adjacent to pavement widening shall be considered as Type A, B, C, or D.

Type A shoulders shall consist of blading over the foreslope both the soil excavated from the trench and any material of the shoulder lying above the proposed, finished shoulder line.

Types B and C shoulders shall consist of excavating all material lying above the normal proposed shoulder line and hauling and depositing it at the direction of the Engineer within a free haul limit of 1 mile (1.6 km).

Type D shoulders shall consist of blading the soil excavated from the trench over the shoulder and shaping the shoulders and slopes, the cost of which shall be included in the contract unit price for trench excavation.

Shoulders shall be finished to a well defined shoulder line with reasonable uniformity in width, no abrupt changes in width, and smooth foreslopes.

2302.10 REMOVAL OF MATERIALS FROM CURBS AND FLUMES.
Unless otherwise provided, the Contractor shall clean up all materials removed from curbs and flumes. These materials will be removed in accordance with Article 1104.08.

Materials removed from curbs and flumes and designated for salvage shall be deposited in areas as designated in the contract documents, with no overhaul allowed.

2302.11 LIMITATIONS.
Unless the road is closed to traffic, the work of constructing concrete pavement widening shall be performed on only one side of the pavement at a time. The widening on one side shall be open to traffic before curb on the opposite side is removed.

The unfilled portion of trench excavation on one side of the pavement shall be backfilled and compacted to provide a surface usable by traffic before any work is done on the other side of the pavement and before paving is opened to traffic.

Compaction required in this operation may be accomplished by rolling with a pneumatic tired roller which has a total weight (mass) of not less than 2000 pounds (900 kg).

At the end of the day, the shoulder disturbed in connection with curb removal, unless protected by barricades, shall be restored to the general elevation of pavement edge.

Articles 1107.08 and 1107.09 shall also apply.

2302.12 OPENING WIDENING TO TRAFFIC.
Concrete widening may be opened to traffic as soon as the concrete has attained the age and flexural strength in accordance with Article 2301.31, and the shoulder has been backfilled.

2302.13 METHOD OF MEASUREMENT.

A. Excavation, Class 13, for Widening.
Article 2213.14, C, shall apply.

B. Removal of Curb.
Article 2213.14, A, shall apply.

C. Pavement Widening.
The quantity of PCC Pavement Widening, in square yards (square meters) will be the quantity shown in the contract documents. The thickness of the pavement will be determined as provided in Article 2301.34.

D. Shoulders.
The quantity of Type A, B, and C Shoulders, in stations (meters), will be the quantity shown in the contract documents. Finishing of earth shoulders will not be measured separately but shall be considered as incidental work included in construction of shoulders. Construction of Type D shoulder shall be considered as incidental to excavation and will not be measured for payment.

E. Removal of Flumes.
Article 2213.14, B, shall apply.

F. Portland Cement Concrete Pavement Samples.
Article 2301.34, I, shall apply.

2302.14 BASIS OF PAYMENT.

A. Excavation, Class 13, for Widening.
Article 2213.15, C, shall apply.

B. Removal of Curb.
Article 2213.15, A, shall apply.

C. Pavement Widening.
The Contractor will be paid the contract unit price for PCC Pavement Widening per square yard (square meter) as provided in Article 2301.35. This payment shall be full compensation for construction of the pavement widening and all other work not paid for under other items.

D. Shoulders.
The Contractor will be paid the contract unit price for Type A, B, and C Shoulders per station (meter). Construction of Type D shoulder shall be considered as incidental to excavation and shall be included in the contract unit price for excavation.

E. Removal of Flumes.
Article 2213.15, B, shall apply.

F. Portland Cement Concrete Pavement Samples.
Article 2301.35, I, shall apply.