(A) Excavation. Excavation shall be made to the required depth and the subgrade or base upon which the curbing is to be set shall be compacted to a firm, even surface.
(B) Dimension of curbs. Concrete curbs shall be not less than 18 inches deep, 6 inches wide at the top and 9 inches wide at the bottom, battered on pavement side. The 2 top edges shall be rounded off in a suitable manner.
(C) Forms. Either 1 1/2 inch plank or approved steel forms must be used on both sides of the curb for the entire depth. The forms shall be smooth and clean, well oiled and perfectly tight, and special precautions shall be taken to prevent leaking at the ends of forms.
(D) Mixture. All references to mixture under § 96.12 of this chapter, shall apply here. Also refer to the latest revision of § 6.01, Class "A" Concrete, Standard Specifications for Roads, Bridges and Incidental Construction, state highway department.
(E) Placing of cement concrete:
(1) Cement concrete shall be placed only on a moist subgrade. Cement concrete shall not be placed on a soft, muddy or frozen subgrade.
(2) The cement concrete shall be placed in the forms, struck off with a template, compacted by approved means and finished to a smooth, even surface. Care should be taken to spade well along the forms to prevent honeycombing.
(3) The cement concrete curbing shall be constructed in sections having a uniform length of approximately 10 feet, unless otherwise directed. No section less than 6 feet shall be permitted.
(4) All sections shall be separated by a standard 1/2 inch specially prepared asphaltic joint filler.
(F) Curing and protection. After the surface of the cement concrete curb has been given its final finish, it shall be protected by completely covering it with moist mats of size and quality as approved by the engineering department or by use of burlap. The mats and the burlap must be kept saturated for a minimum of 10 days in June, July, August or a minimum of 7 days in other months.
(G) Removal of forms. Forms shall not be removed from freshly placed cement concrete until it has set for at least 12 hours. They shall be carefully removed and in such manner that no damage shall be done to the curb or adjacent pavement. Immediately after the forms have been removed the joints shall be thoroughly cleaned and all honeycombed areas pointed up.
(H) Back filling. No material shall be placed against the curb until such time as it can be tamped thoroughly without injury to the curb, after which time the material shall be deposited in thin layers and thoroughly compacted. No large pieces of stone or gravel shall be within 2 inches of the curb.
('66 Code, § 59-16)