Cross-section of conduit, Newark, N. J. Expanded metal reinforcement.
Tanks, Standpipes, Reservoirs.
This waterproof quality of reinforced concrete recommends it as a material for tanks and reservoirs. In 1903 a water tower was built at Fort Revere, Massachusetts, for the United States Government, ninety-three feet in height, octagonal in section, enclosing a tank twenty feet wide, fifty feet high, with walls six inches thick at the bottom, three at the top, coated inside with an inch of Portland cement. At Louisville, Kentucky, a reservoir has been built 394 by 460 feet, and about twenty-five feet high. Its walls and columns are concrete, its roof is in reinforced concrete disposed as groined arches, each of nineteen feet clear span. A reservoir wholly of reinforced concrete at East Orange, New Jersey, is 139 by 240 feet, with a height of 221⁄3 feet. In the early days reinforced concrete was used for water-pipes: more than a hundred miles of such pipes are now in service in Paris. Water-pipes on the Coignet system employ thin steel rods hooked at both ends and curved into encircling hoops. Other rods laid lengthwise run through the hooks, so as to hold each part of the framework securely in place. At Newark, New Jersey, 4,000 feet of single and 1,500 feet of double 60-inch conduits, reinforced with 3-inch expanded steel, have been recently laid.
The material thus available for systems of water supply is also impressed into tasks of sewerage. In Harrisburg, Pennsylvania, a sewer of this kind three miles long intercepts all other sewers, carrying the whole stream below the city to an outfall in the Susquehanna River. A water culvert, for somewhat similar duty, may on occasion be so heavily reinforced as to carry railroad tracks with safety, as in a [culvert] for a Western railroad shown in an accompanying figure.
Water culvert.
New York Subway.
Part of the New York Subway is of reinforced concrete. Steel rods, about 11⁄4 inches square were laid at varying distances according to the different roof loads, from six to ten inches apart. Rods 11⁄8 inches in diameter tie the side walls, passing through angle columns in the walls and the bulb-angle columns in the centre. Layers of concrete were laid over the roof rods to a thickness of from eighteen to thirty inches, and carried two inches below the rods, imbedding them. For the sides similar square rods and concrete were used and angle columns five feet apart. The concrete of the side walls is from fifteen to eighteen inches thick.
River des Pêres Bridge, Forest Park, St. Louis.