All curbs and gutters hereafter constructed in the city shall conform with the following specifications and regulations, which are on file in the office of the Clerk-Treasurer, and shall be subject to approval by the proper officials of the city.
(A) Types and design of combined curbs and gutters. The combined curb and gutter may consist of either the vertical curb type or the “rolled” type curb, though one type, only, shall be used on both sides of any street and between street intersections.
(1) Vertical type. The curb shall have a thickness of six inches, a vertical height of 12 inches in the rear, and a vertical height of six inches in front. The gutter portion shall be six inches in thickness, 18 inches in width, and the outside edge of the gutter pan, on the top, shall be one inch higher than the pan where the pan joins the curb. The outer edge of the curb, at the top, shall be rounded to a radius of one inch and the junction of the curb and the top of the gutter pan shall be rounded to a radius of three-fourth inch. The inner edge of the curb and the outer edge of the gutter pan shall be rounded to a radius of one-fourth inch.
(2) Rolled-type; alternative designs. The entire width of the curb and gutter shall be 24 inches with all measurements being the same as in the vertical curb type, excepting that the junction of the face of the curb with the top of the curb shall be rounded to about a four-inch radius, the face of the curb shall slope about one to one, and the junction of the top of the pan with the face of the curb shall be rounded to about a six-inch radius. However, any other type or design of rolled-type curb which maintains essentially the curvatures herein required may be used if approved by the City Engineer. The combined curb and gutter of either type shall be built in uniform sections of ten feet, excepting where shorter sections are required for closures. No section shall be less than four feet in length. The sections shall be separated by steel templets of a thickness of about one-eighth inch, excepting that at intervals of 40 feet and at the beginning and ending of all curb returns, a one-half inch of preformed expansion joint material shall be inserted. Steel templets, as well as the preformed expansion joint material, shall be set truly perpendicular, the steel templets being carefully withdrawn after the concrete has sufficiently hardened. The preformed expansion material shall be placed between the back of the curb and any abutting sidewalk or structure. All edges at the joints shall be rounded to a radius of about one-fourth inch.
(B) Excavation and fill requirements. The subgrade for the combined curb and gutter shall be excavated or filled to the required depth below the finished surface in accordance with the lines and grades established by the city. All soft and yielding spots and all unsuitable material shall be removed and the entire subgrade shall be thoroughly compacted to a firm, smooth surface. All fill material required to bring the bottom of the curb and gutter to the required subgrade elevation shall consist of pea gravel, coarse sand, or other approved material, all of which shall be placed on a well-compacted base.
(C) Construction of concrete forms; inspection. Forms shall be accurately set to line and grade and shall be of sufficient strength to successfully resist springing out of shape during the process of depositing the concrete. The forms shall be securely staked and held firmly in position and shall be sufficiently tight to prevent leakage of mortar. No concrete shall be placed within the forms before the same have been inspected and approved by an authorized official of the city.
(D) Concrete specifications. The portland cement concrete used in the construction of combined curbs and gutter shall be capable of developing an ultimate compressive strength of not less than 3,000 pounds per square inch in 28 days. “Ready mixed” concrete shall be transit mixed and shall be mixed and delivered in accordance with the Standard Specification for Ready Mixed Concrete, ASTM Designation C-94. If the concrete is mixed at the site, the amount and size of aggregates and the amount of water used, together with the manner of mixing and placing, shall be such as will produce a concrete with the compressive strength herein set out. Excessive over mixing, requiring additions of water to preserve the required consistency, will not be permitted.
(E) Placing of concrete. Concrete shall be placed within the forms before initial set has occurred, and in no event after it has contained its water content for more than 30 minutes. Retempering to preserve required consistency will not be permitted. The concrete shall be deposited within the forms in the quantity that, after being compacted, the surface shall be at the required grade. The concrete shall be tamped and spaded until mortar entirely covers the surface, after which it shall be finished true and even with a wood float.
(F) Finishing and curing. After the concrete has been placed within forms and shall have been well tamped and spaded, and has sufficiently hardened, then the forms shall be removed and any minor defects filled with one to two mortar and then rubbed smooth with a wood float. Then the exposed surfaces shall be rubbed smooth and finished true and even while the concrete is still green. The surface shall be smoothed by rubbing with a mortar brick or wood block, using plenty of water either by dipping the block or brick in water or by throwing water on the surface with a brush. The combined curb and gutter shall be kept moist for not less than 48 hours either by maintaining water on the surface, by covering with a plastic cloth, or by spraying a water proofing compound over the surface to form a film.
(1985 Code, § 5-1-1) (Ord. 7-1958, passed - -1958) Penalty, see § 10.99