SEC. 43-49. SUBGRADE DETERMINATION.

   Foundations or subgrades for all work shall be set at the grades determined by the director. Inspection of such foundation or subgrade must be made and approved by the director before concrete is placed on it. (Ord. Nos. 8590; 22026)

SEC. 43-50. FORM, SPECIFICATIONS, AND PLACEMENT.

   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)

SEC. 43-51. CONCRETE - INGREDIENTS AND CONSISTENCY REQUIRED.

   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)

SEC. 43-52. SAME - PLACEMENT.

   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)

SEC. 43-53. SAME - PROTECTING AGAINST EXTREME TEMPERATURES, ETC.

   Concrete shall be protected against freezing or excessive heat. Concrete shall be kept continuously moist for four days. Concrete shall be protected from traffic until it has developed 80 percent of the required strength. (Ord. 8590)

SEC. 43-54. EXAMINATION AND APPROVAL OF MATERIALS PRIOR TO USE.

   The director may inspect any and all materials before pouring the concrete. The contractor shall furnish the required samples when requested for the making of tests and other required examinations prior to the use of the materials. (Ord. Nos. 8590; 22026)

SEC. 43-55. ALL WORK TO COMPLY WITH ESTABLISHED LINES AND GRADES.

   The work authorized by construction permits issued pursuant to this article must be aligned with the stakes and set to the grade as determined by the director. (Ord. Nos. 8590; 22026)

SEC. 43-56. PROTECTION OF GRADE AND LINE STAKES.

   Stakes set by the director must be protected by the contractor. Grade and line stakes must be set by the director upon request. (Ord. Nos. 8590; 22026)