The combined curb and gutter shall consist of a curb six inches wide at the top and eight inches high above the gutter when it joins the curb, and a gutter 24 inches wide and six inches deep, so constructed that the curb and gutter shall be monolithic. It shall be composed of a concrete core or backing, faced with one inch in thickness of facing or finish mortar, as shown by drawing in the office of the City Engineer. The core or backing shall be constructed of concrete compound of one part portland cement and four parts of mill-tailings or broken limestone, which shall be well mixed dry, and then sufficient water added and the mixing continued until a uniform composition and the proper consistency is produced. The concrete shall then be put in place and well compacted by ramming with a 20-pound rammer until the moulds are full and curb is ready for surfacing. The entire exposed surface of the curb and gutter shall be faced with mortar, one inch in thickness, composed of equal parts of portland cement and clean river sand, floated and troweled so as to give a uniform surface and color throughout. The work shall be carried on uniformly, and the whole curb and gutter completed while in a soft and plastic state, so that it will become a monogenous solid when set. Sections in the curb and gutter shall not be less than six feet long, nor more than seven feet long. The curb and gutter shall be constructed as shown on drawings on file in the office of the City Engineer. The face corner of the curb shall be rounded to a radius of two inches. The corner where curb meets the gutter shall be rounded to a radius of 1½ inches. The gutter flag to be laid to a pitch not exceeding two-thirds of an inch to the foot. At the street corner the curb shall be constructed on a curve of four feet radius, and at the intersection of the alley lines, to a curve of two feet radius. Excavation for combined curb and gutter shall be made to a depth of 12 inches below the intended surface of the gutter. Whenever loose, soft, spongy or loamy soil is found in the excavation it shall be removed to such additional depth as may be directed by the City Engineer or his assistant, and shall be refilled with good material and the whole subgrade compacted by ramming. All such excavations and refilling shall be included in the contract price for the curbing and gutter. After the grading and shaping is done, a foundation of mill-tailings or broken limestone, six inches thick, shall be placed on the subgrade, which shall be consolidated by ramming to an even surface, and shall be moistened just before the concrete is placed thereon.
(`83 Code, § 14-211) Penalty, see § 101.99