Sidewalk construction, reconstruction, rebuilt or repaired in City streets shall be of cement concrete composed of properly proportioned, clean, fine and coarse aggregate, portland cement and water, each having such physical properties that when mixed to a homogenous mass and deposited to a sufficient depth upon the proper subgrade, worked and finished to a smooth and true surface and properly protected against the effects of the elements, the hardened resulting concrete sidewalk will sustain, without failure, a compressive load of 1,500 pounds per square inch at the end of seven days or 2,500 pounds per square inch at the end of 28 days when tested in the usual manner. Such sidewalks shall, in addition, meet the following minimum requirements.
   (a)   No sidewalks shall be less than four inches in thickness and no sidewalk which crosses existing or proposed driveways or roadways, shall have a strength less than one and one-half times that required for ordinary walks or less than one and one-half times that required for ordinary walks or less than six inches in thickness.
   (b)   All aggregates shall consist of uniformly graded, clean, hard particles of natural sand or rock or fragments of stone or gravel free from soft stone, coated or nondurable substances. All water shall be free from injurious amounts of deleterious substances. Cement shall be of good durable and usable quality.
   (c)   The quantity of cement used shall not be less than one and six-tenths barrels per cubic yard of concrete in the sidewalk.
   (d)   All sidewalks shall be constructed in a thorough and workmanlike manner. The grade of the finished walk shall have a fall toward the street gutter of one-fourth inch per foot of width of sidewalk. Joints and surface edges shall be formed to a radius of about one-half inch with proper tools and the surface shall be finished in such a manner that when completed, it shall have a neat appearance and wearing surface equal in roughness to troweling smooth and brushing lightly with a stiff brush or broom.
   (e)   All sidewalks shall be laid on a firm, well- compacted subgrade of cinders or earth free from vegetable matter or a refuse. Any cut or fill shall be not less than one foot wider on each side than the width of the walk to be built upon it and shall have a side slope not less than one and one-half foot horizontal to one foot vertical.
   (f)   All sidewalks constructed or repaired when the temperature of the air is below 40°F. and falling during the period of placing the concrete or during the first five days of curing period or which is laid in extremely warm weather, shall be protected in such a manner as will assure quality and strength of concrete equal to that produced in ordinary temperature.
   (g)   Construction joints spaced not more than five feet apart, shall be cut entirely through the walk for its full width and shall completely separate adjacent slabs. Expansion joint material thoroughly impregnated with a bituminous or asphaltic compound shall be placed between walks and curbs at all places where they meet and in intermediate joints at distances not to exceed 50 feet and shall extend from the finished sidewalk surface for the full depth of the walk.
   (h)   Every sidewalk built or repaired shall have stamped thereon in neat letters not less than one and one-half inches in height and one-fourth inch in depth the year in which the mark shall be placed once in every 100 linear feet of sidewalk.
(Ord. 505, passed 10-5-1942; Ord. 1733, passed 7-29-1963)