609Curb and Gutter

Curb and Gutter

609.1DESCRIPTION

1 This section describes the requirements for constructing curb and gutter.

609.2MATERIALS

1 Provide materials in accordance with the following:

Material Subsection Admixtures 801.4 Aggregate for Concrete 803 Curing Materials 802.1 Fly Ash 801.2 Joint Materials 807 Joint Sealer 807.1 Portland Cement 801.1 Reinforcing Steel 811.1 Water 814.1

609.3EQUIPMENT

1 Ensure that equipment meets the following:

Equipment Subsection Batch Plant 513.3.1 Mixers 513.3.2 Placing Equipment 513.3.3

2 Use a slip-form machine capable of placing, spreading, consolidating, screeding, and finishing concrete in one complete pass, providing a dense and homogeneous section with minimal hand finishing. Ensure that the forming tube portion of the extrusion machine can be readily adjusted vertically during forward motion to produce a variable curb height matching the predetermined curb grade.

609.4CONSTRUCTION

609.4.1 General

1 Construct the foundation to a depth and width allowing the installation and bracing of forms or operation of a slip-form paver. Compact the foundation in accordance with Subsection 203.4.3, Embankment and Cut Areas with Moisture and Density Control, and

Curb and Gutter SECTION 609 shape to the section specified. Remove soft and yielding material and replace with approved material. 2 When constructing gutter next to existing pavement, locate the top front edge of the gutter flush with the top of the surfacing. If the top lift is wearing course, locate the top front edge flush with the contact point between the plant mix pavement and the wearing course or ¾ in [19 mm] below the wearing course surface, whichever is lower. 609.

4.2Placing Concrete

609. 4.2.1 General 1 Coordinate concrete mixing, delivery, and spreading to ensure uniform progress. 2 Use class B concrete in accordance with Subsection 513.4.4, Mix Design. Form and place concrete in accordance with applicable portions of Subsection 513.4, Construction, modified as follows. Place concrete with forms or a slip- form machine. When placing concrete curb over a slotted drain, cover the slot to keep out foreign material. Do not allow the slot to extend above the flow line of the gutter section. 609. 4.2.2 Formed Method 1 Place forms the full depth of the concrete, straight, and free from warp and to enable the inspection of grade and alignment. Brace and secure forms to maintain alignment and grade during concrete placement. 2 Place and consolidate concrete without segregation. Screed with a straightedge float. 609. 4.2.3 Slip-Form Method 1 Use the machine to shape, vibrate, and extrude the concrete for the full width and depth of the section placed and with a continuous forward movement. Use concrete of a consistency capable of maintaining the curb’s shape without support. 2 Indicate the grade for the top of the curb by an offset guide line set from survey marks. Attach a grade-line gauge or pointer to the machine to enable a continual comparison between the curb placed and the grade indicated by the offset guide line. Alternatively, maintain curb grade by operating the machine on rails or forms set at uniform depth below the predetermined finished top of the curb grade. 3 When placing curb, gutter, and concrete pavement monolithically, match the depth of the curb and gutter section to the pavement depth, and delete the longitudinal curb- and- gutter joint if the overall concrete slab width does not exceed 14 ft [4.2 m].

Curb and Gutter SECTION 609 609.4.3 Joints 609. 4.3.1 General 1 Sawcut joints at right angles to curb lines. 609. 4.3.2 Expansion Joints 1 Install preformed expansion-joint material at the following locations:

sides of driveways; and

ntervals of 150 feet [45 m] or less in continuous runs of curb, curb and gutter, and double gutter.

and there is lateral constraint other than soil on the opposite side of the sidewalk. 2 Use preformed joint material that is ½ in [12 mm] thick, shaped to fit the template, and extends the full depth of the section. Make joints true and straight, and ensure a snug fit of joint material. After curing, check material in each joint for tightness of fit. Mortar loose material in place and cure. Seal with silicone joint sealant. 609. 4.3.3 Contraction Joints 1 Sawcut contraction joints ⅛ in [3 mm] wide and from one- third to three-quarters the depth of the section. Space joints to coincide with joints in adjoining concrete and at intervals from 4 ft [1.2 m] to 10 ft [3 m]. After curing seal with silicone joint sealant. 609. 4.3.4 Construction Joints 1 Make construction joints between curb and gutter and concrete pavement that are:

e Y when no lateral constraint exists behind the curb.

2 The department considers the pouring of concrete against a foundation or other fixed object full lateral constraint. Soil is not considered full lateral constraint.

Curb and Gutter SECTION 609

3 Place reinforcing steel required for type Y joints perpendicular to the curb face as specified.

609.4.4 Finishing

1 When using forms, trowel exposed surfaces smooth and give a fine brush finish with brush strokes parallel to the curb line. After removing forms, fill surface blemishes that will be exposed with grout and finish.

2 When using the slip-form method, remove blemishes and give surfaces that will be exposed in the completed item a fine brush finish with brush strokes parallel to the line of the curb.

609.4.5 Curing

1 Immediately after finishing, cure the curb and gutter for five calendar days using impervious curing compound or the water method in accordance with Subsection 513.4.13, Curing Concrete.

609.4.6 Surface Tolerance

1 Ensure that the finished top and face of the curb are true and straight and that the top surfaces are of uniform width and free from irregularities. Do not leave the finished surface with variation greater than 3/16 in [5 mm] every 10 ft [3 m] in any direction. Correct excess variation by removing and replacing the curb section.

609.5MEASUREMENT and PAYMENT

609.5.1 General

1 The engineer will measure:

parallel to the finished surface between neat edge lines, making no deduction for appurtenances with less than one square yard [one square meter] surface area.

face of the curb, making no reduction in length for drainage structures installed in the curb such as catch basins, drop inlets, etc.

Curb and Gutter SECTION 609

2 The department will pay as follows:

Pay Item

Pay Unit Measure to the Nearest Pay to the Nearest Curb and Gutter Type FT [m] 0.1 ft [0.05 m] FT [0.5 m] Double Gutter SF, SY [m2] 0.1 ft, 0.1 ft [0.05 m] SF, 0.1 SY [0.1 m2] Special Curb Type FT [m] 0.1 ft [0.05 m] FT [0.5 m]

609.5.2 Pay Adjustment

1 When the engineer requires an increased thickness for items paid for by area, the quantity for payment will be computed by multiplying the actual area by the relationship of the increased thickness to the specified thickness.