(A) Cement concrete sidewalks. These sidewalks shall consist of a minimum of 4 inches finished thickness of cement concrete on a foundation course of a minimum of 4 inches compacted thickness. Top course and foundation shall be of the same width.
(B) Excavation. Excavation, including removal of all existing sidewalk, shall be made to the required depth and width below finished grade. All soft and yielding or other unsuitable materials shall be promptly removed from the street. Under certain conditions, if approved by the engineering department, existing sidewalk may remain and be resurfaced.
(C) Foundation:
(1) The excavation shall be filled with good cinders, gravel, broken stone or other suitable material which meets the approval of the engineering department, well tamped or rolled to a minimum of 4 inches compacted thickness. Cinders shall be moderately coarse, gritty and free from large lumps and powdery material.
(2) When gravel is used, it shall conform to the latest revision of requirements of Article 2.10.02 for gravel fill of the latest revision of Standard Specifications for Roads, Bridges and Incidental Construction, Connecticut State Highway Department. This foundation shall be thoroughly compacted.
(D) Forms for cement concrete. Forms shall be of metal or wood; straight, free from warp and of sufficient strength to resist springing from the pressure of concrete. Forms shall be of a depth equal to the depth of the sidewalk. Forms shall be securely staked, braced and held firmly in place to the required line and grade and shall be sufficiently tight to prevent leakage of mortar. All forms shall be cleaned and oiled or wetted before concrete is placed against them.
(E) Expansion and contraction joints. Contraction and expansion joints must be placed in sidewalk construction. Contraction joints will not be spaced more than 5 foot intervals. Expansion joints must be placed wherever the sidewalk meets another walk, driveway, building, wall, merestone, catch basin or any rigid object. Expansion joints must consist of premolded asphaltic material 1/2 inch minimum thickness and as wide as the depth of the walk. In any case, expansion joints will not exceed 50 foot intervals.
(F) Composition of mix. The mixture shall consist of one part cement, 2 parts sand and 3 parts trap rock proportioned, mixed, placed, etc., in accordance with the latest revision of § 6.01 for Class -A- Concrete of the latest revision of Standard Specifications for Roads, Bridges and Incidental Construction, Connecticut State Highway Department.
(G) Materials:
(1) Cement shall be air-entraining portland cement with 6 + 1 % air content by volume. Portland cement shall conform to the latest ASTM C 175 Type 1A.
(2) Concrete aggregates shall conform to tentative specifications for Concrete Aggregates ASTM C 33, and shall meet the requirements of Article 6.01.02 except that the trap rock shall consist of commercial 3/4 inch sized aggregate.
(H) Water. Water shall conform to requirements of Article 4.01.02 and not more than 6 gallons per sack of cement shall be permitted in the mix. Water used in mixing concrete shall be clean and free from deleterious amounts of acids, alkalies or organic materials. The amount of water added shall in no case produce a slump of more than 4 inches. Concrete producing more than a 4 inch slump will be rejected.
(I) Measuring and mixing for cement concrete mixture:
(1) All stone, sand and cement used in cement concrete walks, aprons and curbs and combined curbs and gutters shall be accurately measured in a manner satisfactory to the engineering department.
(2) A bag of cement containing 94 pounds may be taken as one cubic foot in proportioning mixtures.
(3) The cement concrete shall be thoroughly mixed by machine in a manner satisfactory to the engineering department. The concrete shall be mixed only in the quantity required for immediate use. Retempering concrete shall not be permitted. Hand mixing will be permitted only for patching.
(4) Concrete shall be mixed in the approved batch mixer for a period of not less than 1 1/4 minutes after all materials except a part of the water are in the drum, during which time the drum speed shall be not less than 14 nor more than 20 revolutions per minute. Any concrete which has been mixed for less than the required time or more than 30 minutes or has developed initial set will be rejected. If a project is of such a nature that concrete cannot be poured within the 30 minutes, smaller loads must be ordered. Under no circumstances will a mixing truck be allowed to remain on a project more than 30 minutes. No mixer will be allowed on a project from another project. For small load requirement. new loads will be ordered unless all concrete can be deposited within 30 minutes.
(J) Transporting of cement concrete mixtures. The transporting of cement concrete mixtures shall conform to the requirements of §§ 6.01.01 and 6.01.03 of the latest revision of Standard Specifications for Roads, Bridges and Incidental Construction, Connecticut State Highway Department.
(K) Placing cement concrete. The properly proportioned and mixed concrete shall be placed in one course in accordance with § 6.01.
(L) Finishing cement concrete. The surface of the concrete shall be finished with a wood float or by other approved means. The surface shall not be overfloated, thereby causing segregation in the mix. The outside edges of the slab and all joints shall be edged with a 1/4 inch radius edging tool. Each slab shall be divided into 2 or more sections by forming dummy joints with a jointing tool as directed. No floating or edging shall be accomplished on a wet surface.
(M) Protecting cement concrete work. The contractor shall protect the work, during the construction, by suitable barricades to protect the public and from damage from any and all causes. In extremely hot weather, the cement concrete shall be protected from the direct rays of the sun. The finished work shall be protected from rains until it has hardened sufficiently to eliminate danger from this source. In cold weather the work shall be protected from freezing. The work shall be barricaded to prevent damage from traffic until such time as the cement concrete has set sufficiently to sustain the traffic. Barricades shall not be permitted for more than 48 hours without written consent of the engineering department and if not removed upon notice to do so will be removed forthwith at the expense of the owner or contractor.
(N) Curing. Ali cement concrete sidewalk shall be cured by either of the following methods:
(1) Apply a fine spray of a colorless membrane curing compound. The compound shall be acceptable to the engineer and shall be sprayed with approved equipment.
(2) Wet burlap coverings, hay or straw or other approved covers, kept wet and retained in position for a minimum of 5 days.
('66 Code, § 59-11)