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Materials used in sidewalks, curbs, drives, gutters, and pavements shall be in accordance with the following standards:
CEMENT. Portland cement shall conform to the Standard Specifications for Portland Cement (Serial Designation C-150-56) of the A.S.T.M. High-Early-Strength Portland Cement shall conform to the standard specifications for High-Early-Strength Portland Cement (Serial Designation C-150-56) of the A.S.T.M.
FINE AGGREGATE. Fine aggregate shall consist of a natural sand or a combination of natural sand and not more than 50 percent of stone screenings. Sand shall be uniformly graded, composed of clean, hard, durable particles of natural materials free from adherent coatings. It shall contain no lumps, soft or flaky particles, clay, loam, foreign, organic, or other deleterious matter. Stone screenings shall consist of the clean, dustless product resulting from the crushing of stone or gravel, meeting all the requirements for coarse aggregate except for grading. Fine aggregate containing more than five per cent by weight of deleterious substances shall not be used. Fine aggregate shall be well graded in size from coarse to fine, and shall conform to the city of Dallas Addendum to the Public Works Construction Standards – North Central Texas as Published by the North Central Texas Council of Governments, current edition.
All tests for fine aggregate shall be made in accordance with the current applicable methods of tests of the A.S.T.M.
COARSE AGGREGATE. Coarse aggregate shall consist of the uniformly graded, clean, hard, durable, uncoated particles of natural gravel or crushed stone or gravel, free from adhering coatings. Coarse aggregate shall not contain more than five per cent by weight of deleterious substances. Coarse aggregate shall be well graded in size from coarse to fine, and shall conform to the city of Dallas Addendum to the Public Works Construction Standards – North Central Texas as Published by the North Central Texas Council of Governments, current edition.
All tests for coarse aggregate shall be made in accordance with the current applicable methods of tests of the A.S.T.M.
PIT-RUN AGGREGATE. Pit-run aggregate will be permitted provided that portion passing the No. 4 sieve shall conform to these specifications for fine aggregate, and that portion retained on the No. 4 sieve shall conform to these specifications for coarse aggregate.
WATER. Water used in mixing and curing concrete and mortar shall be clean and free from oil, acid, alkali, foreign organic matter, or other deleterious substances. (Ord. Nos. 8590; 31313)
Material for reinforcement shall conform to requirements of the Standard Specifications for Billet Steel Bars for Concrete Reinforcement (A.S.T.M. Designation A-15-57T) for structural, intermediate or hard grade; or for Rail Steel Bars for Concrete Reinforcement (A.S.T.M. Designation A-16-57-T) or for Axle Steel Bars for Concrete Reinforcement (A.S.T.M. Designation A-160-57T) or for Cold-Drawn Steel Wire for Concrete Reinforcement (A.S.T.M. Designation A- 82-34) or for Welded Steel Wire Fabric for Concrete Reinforcement (A.S.T.M. Designation A-185-56T). All reinforcement shall be free from rust, scale, oil, paint and other substances which prevent bonding to the concrete. (Ord. 8590)
Expansion joint filler shall be of the pre-moulded type, one-half inch in thickness; the width shall conform to the section of concrete in which incorporated. Expansion joint filler shall be placed where new work abuts old concrete work. Upon completion of the work, expansion joint filler shall be cut off level with the top of the finished concrete. Expansion joint filler shall conform to the Standard Specifications for Bituminous Types (A.S.T.M. Designation D-994-53) or Non-extruding and Resilient Types (A.S.T.M. Designation D-544-56T). (Ord. 8590)
Forms must be straight, smooth, free from warps, and aligned with the stakes set by the director and must be of sufficient strength to retain this alignment. Depth must be not less than the total thickness of the section for which used. Forms must be securely staked, anchored, braced, and set to the established line and grade, the upper edge conforming to the grade of the finished work. Forms must be cleaned of all mortar and dirt. Surface for forms next to concrete may be required to be oiled. Forms must be of either wood or metal. (Ord. Nos. 8590; 22026)
Concrete shall consist of a mixture of Portland cement, fine and coarse aggregate and water in such proportions that will secure a dense, plastic, workable concrete of the strength specified at 28 days. The quantity of water specified per sack of Portland cement shall include the moisture on the surface of the aggregate, but shall not include the amount of water absorbed by the aggregates in 30 minutes. Concrete which has partially set shall not be retempered or remixed by adding additional ingredients. Concrete shall not be mixed during freezing weather, and shall not be placed when the temperature is 40°F. or less. No frozen ingredients or conglomerates shall be used in concrete. Test for slump of concrete shall be made in accordance with the Method of Test for Consistency of Portland Cement Concrete (Serial Designation C-143-52) of the A.S.T.M. All tests for ingredients and concrete shall be made in accordance with the current applicable methods of tests of the A.S.T.M. (Ord. 8590)
Concrete shall be placed in as near its final position as possible, and in such manner as to prevent separation or segregation of the ingredients. Concrete shall be placed in such quantities that after being thoroughly compacted it will be the required thickness, the upper surface true, uniform and parallel to the finished surface. (Ord. 8590)
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