Description
609.01 This work consists of the construction of curb, gutter or combination curb and gutter
per these specifications and in conformity with the lines and grades shown on the plans or established. The types of curb are designated as follows: Type 2 Cast-in-Place Concrete Curb Type 4 Dowelled Concrete Curb Type 6 Sloping Curb The section will be as shown on the plans. Materials
609.02 Except as provided below the materials used shall meet the requirements of the
following subsections: Bed Course Material 703.07 Joint Filler 705.01 Reinforcing Steel 709.01 Concrete for curb shall be Class B and meet the requirements of Section 601. Bituminous curb shall be constructed of the same gradation of aggregate and the same grade of bituminous material as the top layer or top course of bituminous pavement used on the project. Concrete and bituminous mixes will be subject to inspection and tests at the plants for compliance with quality requirements. Construction Requirements
609.03 Cast-in-Place Concrete Curb. All required hand finishing shall be performed in
conformance with subsection 601.12(a).
a.Excavation. Excavation and bedding shall conform to the requirements of subsection 608.03(a).
b.Forms. Forms shall be of wood or metal, straight, free from warp and of such construction that there will be no interference to the inspection of grade or alignment. All forms shall extend for the entire depth of the curb and shall be braced and secured sufficiently so that no deflection from alignment or grade will occur during the placing of the concrete.
c.Mixing and Placing. Concrete shall be proportioned, mixed, and placed per the requirements for the class of concrete specified. Compaction of concrete curb, gutters, or combination curb and gutter, placed in forms shall have thorough consolidation that shall be achieved by tamping and spading, vibrating, or other acceptable methods. Forms shall be left in place until the concrete has set sufficiently so that they can be removed without injury to the curb. Upon removal of the forms, the exposed curb face shall be immediately finished to a uniform surface. For the purpose of matching adjacent concrete finishes or for other reasons, the Engineer shall approve methods of finishing. Plastering will not be permitted. 609-1 609.04
d.Sections. Curb shall be constructed in sections having a uniform length of 10 feet unless otherwise ordered. Sections shall be separated by open joints 1/8 inch wide except at expansion joints.
e.Expansion Joints. Expansion joints shall be formed at the intervals shown on the plans using a 1/2-inch preformed expansion joint filler. When the curb is constructed adjacent to or on concrete pavement, expansion joints shall be located opposite the expansion joints in the pavement. Expansion joints shall be installed between the concrete curb and any fixed structure or bridge. Expansion joint material shall extend the full depth of contact surface.
f.Curing. Immediately upon completion of the finishing, the curb shall be moistened and kept moist for three days, or the curb shall be cured by the use of membrane-forming curing compound. The method and details of curing shall be subject to the approval of the Engineer.
g.Backfilling. After the concrete has set sufficiently, the spaces in back of the curb shall be backfilled to the required elevation with suitable material, which shall be thoroughly tamped.
h.Curb Machine. With the approval of the Engineer, the curb may be constructed by the use of a curb-forming machine.
i.Surface Tolerance. The Engineer may determine that the exposed surfaces of the concrete curb, gutters, or combination curb and gutter shall be tested with a 10-foot straightedge laid along the exposed surface in a longitudinal direction. The Contractor shall furnish an approved 10-foot straightedge and provide an operator to aid the Engineer in testing the exposed surfaces. All surfaces shall be measured in a longitudinal direction. Deviation of any exposed surface in excess of that specified shall be corrected at the Contractor’s expense. Longitudinal surface tolerances for the top and face are:
1.On tangent roadway alignments and curves with a radius greater than 1,000 feet: 0.25 inch from the edge of the straightedge.
2.On sharp vertical curves and horizontal curves with a radius of 1,000 feet or less: 0.25 inch from the edge of the straight edge with allowance made for curve deflection.
609.04 (unused)
609.05 Bituminous Curb.
a.Preparation. Bituminous curb shall be placed on a clean dry surface. Immediately before placing the bituminous mixture, the surface shall receive a tack coat of bituminous material of the type and grade approved by the Engineer. The rate of application of the tack coat material shall be 0.05 to 0.15 gallons per square yard of surface. In the application of this tack coat, the Contractor shall prevent the spread of this tack coat to areas outside of the area to be occupied by the curb. 609-2 609.06
b.Placing. Bituminous curb shall be constructed by using a self-propelled curb machine or a paver with curb attachments. The automatic curb machine shall meet the following requirements and shall be approved before its use:
1.The weight of the machine shall be such that compaction is obtained without the machine riding above the bed where the curb is constructed.
2.The machine shall form curb that is uniform in texture, shape and density.
3.The Engineer may permit the construction of curb by other means, when short sections or sections with short radii are required, or for such other reasons as warranted. The resulting curb shall conform in all respects to the curb produced by the use of the machine. Upon completion of placement of bituminous curb, a fog coat of emulsified asphalt shall be placed on the exposed surfaces of the curb at the rate of approximately 0.1 gallon per square yard.
c.Painting and Sealing. When sealing or painting is required, it shall be performed only on a curb that is clean and dry and that has reached the ambient temperature. Method of Measurement
609.06 Curb will be measured by linear foot along the front face of the section at the finished
grade elevation. Gutter will be measured along the centerline of the gutter. Curb and gutter will be measured along the face of the curb. Deduction in length will be made for drainage structures, such as catch basins, drop inlets, etc., installed in the curb, gutter, or curb and gutter. Basis of Payment
609.07 The accepted quantities will be paid for at the contract unit price for each of the pay
items listed below that appear in the bid schedule, including dowels and expansion joint material. Payment will be made under: Pay Item Pay Unit Curb, Type__ (Section____) Linear Foot Gutter, Type__ (____Foot) Linear Foot Curb and Gutter, Type__ (Section____) Linear Foot Bed course material will be measured and paid for per Section 206. Fog coat and tack coat for Curb Type 6 will not be measured and paid for separately but shall be included in the work. 609-3 609.07 This Page Intentionally Left Blank 609-4 610.01
Curb and Gutter in other states
Get an email when 609 changes
Colorado revises spec sections through supplementals and new editions. We check this one every week and email you the day it changes. Free, no account.
Source: 2025 Standard Specifications for Road and Bridge Construction, 2025 Edition. Pages 653–656 of 967. View official source ↗