The materials should be heated in an iron kettle over a gasoline furnace or other controllable fire, until they just commence to bubble and are of the consistency of a thin sirup. Only a sufficient quantity of material for immediate use should be prepared and it should be used within 10 to 15 minutes after it has become properly heated. The ladle used should be large enough to pour the entire joint without refilling. There are other important points to be considered in pouring joints which can be learned best by experience.
The quantity of material necessary for making these joints, as announced by the manufacturers, is shown in Table 65.
| TABLE 65 | ||||||
|---|---|---|---|---|---|---|
| Quantity of Compound Needed for Poured Joints | ||||||
| Diameter of Pipe, in Inches | Quantity of Material in Pounds per Joint | |||||
| Standard Socket | Deep and Wide Socket | |||||
| Jointite | Filtite | G. K. | Jointite | Filtite | G. K. | |
| 6 | 0.82 | 0.72 | 0.42 | 1.46 | 1.28 | 0.72 |
| 8 | 1.06 | 0.95 | 0.73 | 1.82 | 1.60 | 1.25 |
| 10 | 1.30 | 1.15 | 0.89 | 2.26 | 1.98 | 1.52 |
| 12 | 2.08 | 1.82 | 1.42 | 2.65 | 2.32 | 1.80 |
| 15 | 2.52 | 2.20 | 1.74 | 3.20 | 2.80 | 2.20 |
| 18 | 3.02 | 2.64 | 2.58 | 3.75 | 3.29 | 3.25 |
| 20 | 3.44 | 3.00 | 2.86 | 4.30 | 3.78 | 3 60 |
| 22 | 3.62 | 3.16 | 3.13 | 4.62 | 4.07 | 3.97 |
| 24 | 4.03 | 3.50 | 3.41 | 4.91 | 4.31 | 4.27 |
In making a poured joint the pipes are first lined up in position. A hemp or oakum gasket is forced into the joint to fill a space of about ¾ of an inch. An asbestos or other non-combustible gasket such as a rubber hose smeared with clay is forced about ½ inch into the opening between the bell and the spigot and the compound is poured down one side of the pipe through a hole broken in the bell, until it appears on the other side, and the hole is filled. Occasionally the non-combustible gasket is wrapped tightly around the spigot of the pipe and pressed or tied firmly to the bell. In pouring cement grout joints a paper gasket is used which is held to the bell and spigot by draw strings. Greater speed in construction and economy in the use of materials are obtained by joining two or three lengths of pipe on the bank and lowering them into the trench as a unit. The pipes are set in a vertical position on the bank with the bell end up, one length resting in the other. The joint is calked with hemp and poured without the use of the gasket. The joint should always be poured immediately after being calked so that the hemp can not become water soaked. The asbestos gasket should be removed as soon as possible after the joint is poured in order to prevent sticking with resultant danger of breaking of the joint when attempting to pull the gasket free.
One man can pour about 33 eight-inch joints, and two men can complete about 26 twelve-inch joints per hour on the bank where conditions are more or less fixed.
182. Labor and Progress.—The labor required for the laying of pipe sewers, exclusive of excavation, bracing and backfilling, consists of pipe layers and helpers. For pipes 24 to 27 inches in diameter or smaller one pipe layer and one or more helpers are necessary, dependent on the size of the pipe and the depth of the trench. For larger pipes two pipe layers can work economically each working on one-half of the pipe and making half of the joint. The speed of pipe laying is ordinarily limited by the speed of the excavation, but on a job in Topeka, Kan.,[[100]] where the average day’s progress with a machine excavator was 200 to 500 feet of trench per day, the pace was limited by the speed of the pipe laying gang. This gang consisted of two pipe layers in the trench and two helpers on the surface. The sizes of pipes handled were from 8 to 27 inches.
Brick and Block Sewers
183. The Invert.—In good firm ground the excavation is cut to the shape of the sewer and the bricks are laid directly on the ground, being embedded in a thick layer of mortar. After the foundation has been prepared and before the bricks are laid, two wooden templates, called profiles, are prepared, similar to that shown in Fig. 126, to conform to the shape of the inside and outside of the sewer. Each course of bricks is represented by a row of nails in the profile and each nail corresponds to a joint in the row. The two profiles are set true to line and grade. A cord is stretched tightly between the two lowest nails on opposite templates and a row of bricks is laid. The bricks are laid radially and on edge with their long dimension parallel to the axis of the sewer and with one edge just touching the string. As each one or two or three rows are completed the guide line is moved up to the next nails. When the bricks are laid on the ground all but large depressions are filled in with tamped sand or mortar by the masons. Approximately the same number of rows of bricks is kept completed on either side of the center line. The succeeding courses follow within three to five rows of each other, the only bond between courses being the mortar joint. This is called row lock bond and with few exceptions has been used on all brick sewers in the United States. As the sides of the sewer become higher during the construction, platforms must be built for the masons. These platforms are built of wood and rest directly on the green brickwork. They should be designed to spread the load as much as possible. The brickwork of the invert is continued up in this way to the springing line. As soon as one section is completed one profile is moved 10 to 20 feet ahead along the trench according to the standard length of sections, and set in position. The line is then strung from it to nails driven or pushed into the cement joints of the last completed section. Between work done on separate days the bricks are racked back in courses to provide a satisfactory bond.
Fig. 126.—Profile for Brick Sewers.