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SEQ CHAPTER \h \r 1DESCRIPTION: This work shall consist of the furnishing and placing precast concrete paving and bedding materials.  All work shall be in accordance with these specifications and in reasonably close conformity with the lines and grades shown on the plans or established by the Engineer.

MATERIALS: Material shall meet the requirements specified in the following subsections of Section 700 - Materials:

Bituminous Tack Coat (As specified)      702-3601 anionic asphalt emulsion SS-1h

Asphalt Cement for Paving                    702-02 or 702-03

            Fine Aggregates                                    703-01

            Mineral Filler                                         703-08

            Precast Concrete Street Pavers             704-23

            Water                                                   712-01                                             

Precast concrete street pavers shall meet the requirements of §704-23 and shall be the size(s), shape(s) and color(s) as specified in the contract documents.  Minimum thickness of precast concrete street pavers shall be 80 mm.

Neoprene-Modified Asphalt Adhesive shall consist of 2% neoprene, grade WM1, oxidized asphalt with a R & B softening point of 68ºC minimum and a penetration of 80, and 10% asbestos-free fibers.

Polymeric Sand shall be used to fill the joints between the pavers.  Color shall be as specified in the contract documents.

CONSTRUCTION DETAILS: The provisions under §401-3, Construction Details for Plant Mix Pavements - General, shall apply.

Precast concrete street pavers shall be laid in a bituminous setting bed over the specified concrete subbase. Prior to placing the tack coat, the concrete base shall free of moisture, dirt and debris. The tack coat shall be applied at a rate of approximately 1 l/m². Thickness of the compacted bituminous setting bed shall be 20mm.  Do not use the bituminous setting bed to correct deficiencies in the concrete subbase.  The setting bed shall consist of asphalt cement meeting the requirements outlined in either §702-02 or §702-03 mixed with fine aggregate meeting the requirements of §703-01.  The asphalt cement shall be 7.0% of the total batch weight.  The mix shall be heated to approximately 163ºC. The tack coat and setting bed shall be installed when the concrete temperature is 5º C and rising.  A coating of neoprene-modified asphalt adhesive shall be applied by mopping, squeegeeing or troweling over the top surface of the setting bed per manufacturer’s instructions to provide bond under the precast concrete street pavers.

All precast concrete street pavers shall be laid in the herringbone pattern shown in the contract documents or as directed by the Engineer to provide a uniformly even surface.  Joints shall be 2 to 4mm wide unless otherwise specified.  No precast concrete street pavers shall be laid when the air temperature is expected to fall below 5°C.. Joint lines shall not deviate more than ±15 mm over 15m from string lines. Fill gaps at the edges of the paved area with cut pavers or edge units. Adjust pattern at pavement edges such that cutting of edge pavers is minimized. Cut pavers with a masonry saw prior to placing along edge restraints All cut pavers subject to tire traffic shall be no less than one-third (1/3) of a whole unit. After pavers are placed on the adhesive, set them in it with at least one pass of a minimum 135 kg water-filled hand roller. Replace any cracked units with whole units and set them with the hand roller.

Polymeric sand shall be swept over the precast concrete street pavers until the joints are completely filled. The paver surface shall be swept clean and the joints lightly wetted with water.  This joint filling operation shall not be performed if the air temperature is expected to fall below 5°C.

METHOD OF MEASUREMENT: Precast concrete paving will be measured by the number of square meters placed as shown in the contract documents, or as ordered by the Engineer 

BASIS OF PAYMENT: The unit price bid per square meter shall include the cost of all labor, materials and equipment necessary to complete the work, including setting bed material, except that any necessary excavation and subbase course will be paid for under their appropriate items.

 Payment will be made under:

Item No.                                  Item                                                                            Pay Unit

601.XX__18M              Precast Concrete Paving (Bituminous Setting Bed)                      Square Mete