Article 1 — Description
Furnish, construct, and install concrete headwalls and wingwalls for drainage structures and underpasses .
Article 2 — Materials
2.1 General . Furnish materials in accordance with the following.
Item 420, “Concrete Substructures” Item 421, “Hydraulic Cement Concrete” Item 440, “Reinforcement for Concrete” Use Class C concrete for cast -in-place and precast concrete units unless otherwise shown on the plans. Furnish cast -in-place or precast headwalls and wingwalls unless otherwise shown on the plans.
2.2 Fabrication .
2.2.1 General . Fabricate cast -in-place concrete units and precast units in accordance with Item 420. Use the
following definitions for headwalls and wingwalls . Headwalls. R efers to all walls, including wings, at the ends of single-barrel and multiple- barrel pipe culvert structures. Wingwalls. R efers to all walls at the ends of single- barrel or multiple- barrel box culvert structures.
2.2.2 Lifting Holes . Provide no more than four lifting ho les in each section for precast units. Lifting holes may be
cast, cut into fresh concrete after form removal, or drilled. Provide lifting holes large enough for adequate lifting devices based on the size and weight of the section. The maximum hole diameter is 3 in. at the inside surface of the wall and 4 in. at the outside surface. Cut no more than one longitudinal wire or two circumferential wires per layer of reinforcing steel when locating lift holes. Repair spalled areas around lifting holes.
2.2.3 Marking . Clearly mark each precast unit before shipment from the casting or fabrication yard with the
following: Date of manufacture, Name or trademark of the manufacturer, and Type and size designation.
2.2.4 Storage and Shipment . Store precast units on a level surface. Do not place any loads on precast concrete
units until design strength is reached. Do not ship units until design strength requirements have been met.
2.2.5 Causes for Rejection . Precast units may be rejected for not meeting any one of the specification
requirem ents. Individual units may also be rejected for fractures or cracks passing through the wall or surface defects indicating honeycombed or open texture surfaces. Remove rejected units from the project and replace them with acceptable units meeting the requirements of this Item.
2.2.6 Defects and Repairs. Occasional imperfections in manufacture or accidental damage sustained during handling may be repaired in accordance with the Department’s Concrete Repair Manual . The repaired units
will be acceptable if they conform to the requirements of this Item and the repairs are sound, properly finished, and cured in conformance with pertinent specifications. 729 3. CONSTRUCTION
3.1 General . Remove portions of existing structures and drill, dowel, and grout in accordance with Item 420.
3.2 Excavation, Shaping, Bedding, and Backfill . Excavate, shape, bed, and backfill in accordance with
Item 400, “Excavation and Backfill for Structures.” Take special precautions in placing and compacting the backfill to avoid any movement or damage to the units. Bed precast units on foundations of firm and stable material accurately shaped to conform to the bases of the units.
3.3 Placement of Precast Units. Provide adequate means to lift and place the precast units. Fill lifting holes with mortar or concrete and cure. Precast concrete or mortar plugs may be used.
3.4 Connections . Make connections to new or existing structures as shown on the plans. Furnish jointing
material in accordance with Item 464, “Reinforced Concrete Pipe,” or as shown on the plans. Remove a length of the existing pipe from the headwall to the joint when removing existing headwalls as shown on the plans or as approved. Re-lay the removed pipe if approved or furnish and lay a length of new pipe.
Article 4 — Measurement
This is a plans quantity measurement I tem. The quantity to be paid is the quantity shown in the proposal , unless modified by Article 9.2., “Plans Quantity Measurement.” Additional measurements or calculations will be made if adjustments of quantities are required.
4.1 Headwalls. Headwalls will be measured by each end of a structure.
4.2 Wingwalls. Wingwalls will be measured by one of the following methods .
4.2.1 Square Foot . Wingwalls will be measured by the square foot of the front surface area of the wall of each
type. The area will be measured from the top of the footing or apron to the top of the wall unless otherwise shown on the plans. If there is no footing or apron, then measurement is from the bottom of the wall.
4.2.2 Each . Wingwalls will be measured by each end of a structure.
Article 5 — Payment
The work performed and materials furnished in accordance with this Item and measured as provided under “Measurement” will be paid for at the price bid for “Headwalls” of the type and pipe size (diameter or design) specified, “Wingwalls” of the type specified when measurement is by the square foot, or “Wingwalls” of the type and wall height specified when measurement is by each. For payment purposes, the wingwall height will be rounded to the nearest foot. All wingwalls and headwalls of the same type will be paid for equally w hen skew does not affect the type. This price is full compensation for constructing, furnishing, transporting, and installing the headwalls or wingwalls; connecting to existing structure; breaking back, removing and disposing of portions of the existing structure, and replacing portions of the existing structure as required to make connections; excavation and backfill; and concrete, reinforcing steel, corrugated metal pipe or reinforced concrete pipe, equipment, labor, tools, and incidentals. Apron concrete or riprap between or around the wingwalls of single - or multiple -barrel box culvert structures will be measured and paid for in accordance with Item 432, “Riprap.” The removal and re- laying of existing pipe or the furnishing of new pipe to replace existing pipe will not be paid for directly , but will be subsidiary to this Item .