305 SECTION 601 STRUCTURAL CONCRETE
601.1 -DESCRIPTION : This work shall consist of furnishing and placing portland cement concrete for structures, and incidental construction, in accordance with these specifications and in reasonably close conformity with the lines, grades and dimensions as shown on the Plans or established by the Engineer. All concrete shall be air -entrained. Classes of concrete shall be used as indicated below unless noted otherwise on the Plans: Class A concrete shall be used in railing, cribbing, precast shapes, and for filler. Class K concrete shall be used in all sidewalks, parapets, decks, and median barriers when they are a part of the bridge superstructure. Class B concrete shall be used in all beams and girders, roadway sidewalks, columns, hammerhead piers, arch rings including t ies and spandrel walls, rigid frames, box culverts, heavily reinforced abutments, retaining walls, footings, pedestals and other areas not specifically designated as to class of concrete. Class C concrete shall be used in massive footings and pedestals, m assive pier shafts, gravity walls and, in general, for non -reinforced or lightly reinforced concrete. Class D concrete shall be used as unformed and non -reinforced concrete for backfilling of any excavated pockets or voids on which footings are to be loca ted. Class H concrete shall be used for bridge decks and other bridge elements when designated in the plans. Class DC concrete shall be used in rock socketed drilled shafts. If the Contractor so elects, the Engineer may permit the use of a higher class concrete than the particular class designated for the work, in which event the higher class concrete shall meet the Specifications applicable without additional compensation. If the contractor uses a higher class concrete, and the strength specimens do no t meet the minimum strength requirement of that higher class concrete, no penalty will be applied, provided that the strength specimens exceed the minimum strength requirement of the concrete that was originally designated for the work. When called for on the Plans, an admixture of water -reducing retarder shall be added to all concrete so specified. A retarder may be used in other concrete at the Contractor's option. The work will be accepted in accordance with these Specifications and the applicable requirements of sections 105, 106, and 109. All classes of concrete shall be designated as modified when using increased design strengths. All classes of concrete shall be designated as architectural when using additional formwork as shown in Section 601.8.10. A hydration control stabilizing admixture may be used at the Contractor's option provided that the conditions in section 601.7 are met.
601.2 -MATERIALS : Materials shall meet the requirements specified in the following Sections or Subsections of Division 700: