634.01 Description. This item shall consist of the construction
of integral curb, concrete curb, or concrete combin ation curb and gutter according to these specifications and in con formity with the locations, lines, and grades shown on the plans or as directed.
634.02 Materials. The concrete shall comply with the
requirements for Class A or S Concrete as provided in Section 802, or for paving concrete in Section 501. The maximum allowable slump shall be 4 inches (100 mm). The maximum wate r/cement ratio shall not be exceeded. The Contractor shall perform quality control and acceptance sampling and testing in acco rdance with Subsection 802.06. When an extrusion machine is used, the Contractor m ay modify the concrete mix design, upon approval of the Engin eer, to improve workability while maintaining the above strength re quirements. Material for joint filler shall comply with AASHTO M 213.
634.03 Construction Requirements. (a) Subgrade. The
subgrade shall be shaped to the required depth belo w the finished surface, according to the dimensions shown on the p lans, and shall be compacted to a firm, even surface. When possibl e, the subgrade shall be shaped and compacted at the same time and in the same manner as the subgrade for the pavement slab. All soft and yielding areas shall be removed and replaced with suitable m aterial and compacted. 522 When the curb is to be constructed on a concrete su rface previously placed, the area of the concrete surface shall be roughened sufficiently to secure a good bond.
b.Forms. Forms shall be constructed of metal or wood, free from warp, and of sufficient strength to resist spr inging during the process of depositing concrete. They shall be secu rely staked, braced, set, and held firmly to the required line a nd grade. Forms shall be cleaned and oiled before concrete is place d against them. Face forms or templates matching the shape of the p lanned curb will be required when a curb machine is not used.
c.Placing and Finishing. (1) Integral Curb. After the concrete pavement has been struck off, the curb for ms shall be clamped or otherwise securely fastened in place to the slab form and additional concrete for the curb shall then be depo sited and thoroughly tamped. The concrete shall be placed wi thin 30 minutes after the pavement slab has been finished and care shall be taken to secure monolithic construction. The concrete shall be spaded or vibrated sufficiently to eliminate voids and shall be tamped to bring the mortar to the surface. It shall then be finish ed smooth and even with a wood float and given a Class 2 or 6 finish a ccording to Section 802.19. The edges shall be rounded with an approved finishing tool to the radius shown on the plans. The curb may be placed after completion of the pave ment provided dowels are placed in the pavement of the s ize, type, and spacing shown on the plans. No additional cost to the Department shall result from placing the curb by this method.
2.Concrete Curb or Concrete Combination Curb and Gutter. The concrete shall be deposited in the forms upon the wetted subgrade and vibrated and spaded until morta r entirely covers the surface, after which it shall be finished smoot h and even by means of a wood float and given a Class 2 or 6 fini sh according to Section 802.19. Edges shall be rounded as shown on the plans while the concrete is still plastic. Face forms shall be removed from curbs within 24 hours and the face finished by rubbing wi th a wetted cement mortar brick or wood float until it is smoot h. Plastering will not be permitted but minor defects shall be filled with a 1:2 cement mortar (1 part Portland cement to 2 parts concrete sand) applied with a wood float. 523 (d) Joints. Expansion joints for concrete curb or concrete combination curb and gutter shall be installed at s tationary structures such as catch basins, drop inlets, etc., and at end s of curb returns. Where curb and gutter is constructed adjacent to or on rigid pavements, the location and width of joints shall c oincide with those in the pavement, where practicable. Expansion join ts shall have a thickness of ½" (12 mm) and shall be filled with jo int filler shaped to the cross section of the curb and constructed at right angles to the curb line. Contraction joints for concrete curb or concrete co mbination curb and gutter shall be 1/8" to 3/8" x 1½" (3 mm to 10 mm x 38 mm) and shall be constructed at 15' (4.5 m) intervals. They shall be constructed at right angles to the centerline and p erpendicular to the surface of the curb and gutter. Where curb and gut ter is constructed adjacent to or on rigid pavements, the location and width of joints shall coincide with those in the pavement, where pr acticable. Contraction joints shall be formed by sawing, unles s otherwise specified, and filled according to the requirements for Joint Seals as specified in Section 501, or with a commercially av ailable silicone product approved by the Engineer. When the plans s how the horizontal surface of the gutter to be overlaid by the surface course, that surface shall be sawed and sealed before the s urface course is applied.
e.Surface Tests. Before the concrete is given the final finishing, the surface of the gutter and the top of the curb shall be true to line and grade. The maximum variation in 1 0' (3 m) shall not exceed 3/8" (10 mm).
f.Curing. When completed, the concrete shall be cured as specified in Section 501.
g.Backfilling. After the concrete has set sufficiently, the spac e behind the curb shall be refilled to the required e levation with suitable material, which shall be firmly compacted by means of approved mechanical equipment and neatly graded.
634.04 Method of Measurement. Curbing will be measured by
the linear foot (meter) along the face of the curb at the gutter line, excluding the curb and/or curb and gutter within th e limits of drop inlets and drop inlet extensions as shown in the st andard drawings. 524 634.05 Basis of Payment. Work completed and accepted and measured as provided above will be paid for at the contract unit price bid per linear foot (meter) for the respectiv e types or sizes of Integral Curb, Concrete Curb, or Concrete Combinati on Curb and Gutter, which price shall be full compensation for furnishing materials, including joint filler; for forms; for m ixing, placing, and finishing concrete; for performing mix designs and quality control and acceptance sampling and testing; for excavation and backfilling; and for all labor, equipment, tools, and incidental s necessary to complete the work. Payment will be made under: Pay Item Pay Unit Integral Curb (Type__) Linear Foot (Meter) Concrete Curb (Type__) Linear Foot (Meter) Concrete Combination Curb and Gutter (Type__)(__'__" [__ mm]) Linear Foot (Meter)
Source: , Edition.