A. Class “A” Concrete (Structures): Unless otherwise specified, all concrete shall be Class A. 1. Fine Aggregate: proportioned by dry weight of fine to coarse aggregates between 30-45%. 2. Coarse Aggregates: Size No. 57 - Structural Concrete. 3. Minimum Compressive Strength: 28 day, 4000 psi. 4. Slump: 1 to 3 inches for mass concrete and heavy reinforcement section; 2 to 4 inches for slabs, columns, girders, walls, etc. B. Class “P” Concrete (Base and Pavement) 1. Fine Aggregate: do not use sand manufactured from limestone for traffic lane pavements. 2. Coarse Aggregate: Size No. 57. 3. Minimum Compressive Strength: 14 day, 3500 psi. 4. Slump: 2 to 1-1/2 inches, workable consistency. C. Class “B” Concrete: Use for anchors, kickers, encasement for pipelines, sub-foundations, mass footings, and fill (unless otherwise specified). 1. Fine Aggregate: proportion by dry weight of fine to course aggregates between 30 - 45%. Test for potential alkali reactivity (if requested) per ASTM C-289-71. Use natural river sand or specially approved manufactured sand. 2. Coarse Aggregate: Size No. 57 or 67 as specified. 3. Minimum Cement Content: 5.0 bags (470 lbs.) per cubic yard. 4. Minimum Compressive Strength: 28 day, 3000 psi. 5. Slump: 5 to 8 inches for pipe encasements; 2 to 4 inches in sub-foundations and other specified areas. D. Flowable Fill and Pervious Concrete 1. Per TDOT specifications, or 2. Contractor to submit mix design for review and approval
