609.01 609-1 SECTION 609 CURB AND GUTTER 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 sufficie ntly 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 match ing adjacent concrete finishes or for other reasons, the Engineer shall approve methods of finishing. Plastering will not be permitted. 609.04 609-2 (d) Sections. Curb shall be constructed in sections hav ing 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 ap proved 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 C ontractor’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. 609.06 609-3 (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. 609.07 609-4 THIS PAGE INTENTIONALLY LEFT BLANK 610.01 610-1 SECTION 610 MEDIAN COVER MATERIAL DESCRIPTION
610.01 This work consists of the construction of median cover over the median area, or over
other areas designated, per these specifications and in conformity with the lines and grades shown on the plans or established. MATERIALS
610.02 Bituminous median cover material shall conform to the requirements of Section 403
and as shown on the plans. Concrete shall be Class B and shall conform to Section 601. Coloring agent, if required, shall be as shown on the plans or specified. Aggregate for median cover shall conform to the requirements of subsection 703.10. Plastic sheeting shall be black polyethylene with a minimum thickness of 10 mils or approved equal. Herbicides shall conform to the requirements of Section 217. CONSTRUCTION REQUIREMENTS
610.03 Median cover operations shall not be started until the underlying surface has been
compacted, smoothed and, if required, treated with herbicides. Other requirements are as follows:
a.Bituminous Median Cover Material . Bituminous median cover material shall be placed in conformance with the requirements of subsection 608.04(c).
b.Concrete. Construction requirements shall conform to the requirements of subsection
608.03 The surface finish or pattern shall be as shown on the plans or per the recommendations
of the supplier of the median cover material.
c.Stone. Areas to receive stone median cover shall be treated, if required, with an approved herbicide treatment per Section 217 or as directed. Immediately after the placement of the herbicides, the plastic sheeting and stones shall be placed per details shown on the plans, or as specified. METHOD OF MEASUREMENT
610.04 Bituminous median cover material will be measured by the number of tons of
bituminous material placed and accepted. Concrete median cover material will be measured by the square foot of surface placed and accepted. Stone median cover material will be measured by the number of tons of aggregate placed and accepted.
Source: Colorado Standard Specifications for Road and Bridge Construction, 2023 Edition. Pages 631–634 of 943.