Combined Curb and Gutter
Article 1 — Description
Construct hydraulic cement concrete curb, gutter, and combined curb and gutter.
Article 2 — Materials
Furnish materials in accordance with the following. Item 360, “Concrete Pavement” Item 420, “Concrete Substructures” Item 421, “Hydraulic Cement Concrete” Item 440, “Reinforcement for Concrete” Use Class A concrete or material specified on the plans. Use Grade 8 coarse aggregate for extruded Class A concrete. Use other grades if approved. When curbs are monolithically placed with the concrete pavements, use the same class of concrete as the concrete pavement. Use of fibers in accordance with DMS -4550 , “Fibers for Concrete,” to replace reinforcing steel in Class A concrete is allowed unless otherwise shown on the plans. Dose fibers in accordance with the Department’s MPL of pre- qualified fibers for concrete.
Article 3 — Construction
Provide finished work with a well -compacted mass and a surface free of voids and honeycomb, in the required shape, line, and grade. Round exposed edges using an edging tool of the radius shown on the plans. Mix, place, and cure concrete in accordance with Item 420. Construct joints at locations shown on the plans. Cure for at least 72 hr. Furnish and place reinforcing steel in accordance with Item 440 unless fiber reinforced concrete is used. Set and maintain a guideline that conforms to alignment data shown on the plans, with an outline t hat conforms to the details shown on the plans. Ensure that changes in curb grade and alignment do not exceed 1/4 in. between any two contacts on a 10- ft. straightedge.
3.1 Conventionally Formed Concrete . Shape and compact subgrade, foundation, or pavement surface to the
line, grade, and cross- section shown on the plans. Lightly sprinkle subgrade or foundation material immediately before concrete placement. Pour concrete into forms, and strike off with a template 1/4– 3/8 in. less than the dimensions of the fini shed curb unless otherwise approved. After initial set, plaster surface with mortar consisting of one part hydraulic cement and two parts fine aggregate. Brush exposed surfaces to a uniform texture. Place curbs, gutters, and combined curb and gutters in 50- ft. maximum sections unless otherwise approved.
3.2 Extruded or Slipformed Concrete . Shape and compact subgrade, foundation, or pavement surface to the
line, grade, and cross -section shown on the plans. Lightly sprinkle subgrade or foundation material immediately before concrete placement. Provide clean surfaces for concrete placement. Coat cleaned 808 surfaces, if required, with approved adhesive or coating at the rate of application shown on the plans or as directed. Place concrete using approved self -propelled equipment. The forming tube of the extrusion machine or the form of the slipform machine must be easily adjustable vertically during the forward motion of the machine to provide variable heights necessary to conform to the established gradeline. Attach a pointer or gauge to the machine so that a continual comparison can be made between the extruded or slipform work and the grade guideline. Other methods may be used when approved. Finish surfaces immediately after extrusion or slipforming.
3.3 Curb Joints for Concrete Pavements. Provide transverse expansion and contraction joints in the curb of
the same type and location as the adjacent or underlying pavement. Use expansion joint material of the same thickness and type required for the pavement. Extend expansion joints through the curb. Place reinforcing steel for non- monolithic curb construction joints as shown on the plans, unless otherwise approved. Form or saw the contraction joint through the full depth of the monolithic curb.
Article 4 — Measurement
This Item will be m easured by the foot.
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 unit price bid for “Concrete Curb,” “Concrete Curb (Mono),” or “Concrete Curb and Gutter” of the type specified. This price is full compensation for surface preparation of curb foundation, equipment, labor, materials, tools, and incidentals.