§ 8.28.010. Specifications

All sidewalks hereafter to be constructed or rebuilt in the city shall be constructed by hydraulic cement concrete; the concrete to be a mixture of Portland cement, sand and broken stone.

The fine aggregate or sand shall consist of any material of siliceous, granitic or igneous origin, free from mica in excess of five percent, and other impurities, and shall be of graded sizes ranging from a quarter inch down to that which shall be retained on a No. 100 standard sieve, nor more than 20 percent shall pass a No. 50 standard sieve for the base, and from a quarter inch down to that which will be retained on a No. 80 standard sieve, nor more than 20 percent of which shall pass a No. 50 standard sieve for the top or wearing surface.

The coarse aggregate shall be sound gravel or broken stone. It shall be free from foreign matter, uniformly graded and of sizes that will pass a one-inch screen and retained on a quarter-inch screen.

In preparing the concrete for the base of cement and aggregate shall be measured separately and mixed in such proportions that the resulting concrete shall contain fine aggregated amounting to one-half of the volume of the coarse aggregate; and that 5½ cubic feet of concrete in place will contain 94 pounds of cement.

The top or wearing surface shall be composed of one part Portland cement and two parts of fine aggregate, mixed with sufficient water to produce a mortar of a consistency which will not require tamping, and which can be easily spread into position with a straight edge.

All sidewalks shall be of a width prescribed by the chapter of said city and shall be so laid as heretofore or hereafter prescribed by the ordinances of said city.