Asphalte Joint

Asphalte Joint is a means adopted for jointing socketed sewer-pipes, and is said to possess besides the qualities of adhesiveness, elasticity, and imperviousness, the power of resisting penetration by the rootlets of trees. It is made by first of all caulking with two or three strands of tarred gasket and then filling up the remainder of the cavity left in the socket by pouring in asphalte rendered liquid by heat, a temporary belt of clay being passed round the edge of the socket to confine it till solidification ensues.

Bed or Bedding Joint occurs between the bricks, etc, of brick drains and sewers, and should in all cases be solidly made with Portland cement or hydraulic lime ; the interstices between the bricks caused by the quickness of the curve being filled in at the invert, etc, with pieces of slate or tile. It also exists between the invert blocks of sewers and their concrete or clay or other foundation or outside lining when built in porous soils, the puddle lining girting the lower half of the sewer. It occurs likewise between a pipe and the substance on which it lies, and the greatest care is needed in order that drain-pipes may have a solid bearing and bear equally throughout their beds, which must be absolutely exempt from the danger of settlement. The same remarks are applicable to the stoneware invert blocks of brick sewers. Surrounding pipes with concrete thrown into the trench after they are jointed not only strengthens their sides against fracture by crushing but lessens the danger of subsidence. Large pipes sometimes require holes purposely cut in the floor of the trench to take the sockets. In building walls over drainpipes the space of a few inches must be left to allow for the wall's settlement, and the same care is required in piercing old walls for new drains. After springing a line of pipes up into a curved form to insert a junction, the invert must be again truly straightened and the compactness of the foundation restored.

Butt Joint

Butt Joint is formed between the joints of agricultural or surface, or subsoil drain-pipes, consisting of short cylindrical tubes, by merely butting them against one another, end to end. The joint, however, must be protected by slipping over it a perforated collar when laid in running sand or where the bottom is too loose to keep the pipes in line.

Cement Joint

For jointing socketed drain-pipes Portland cement is used, both neat and mixed with an equal part of clean sharp sand; but besides being porous, and therefore not air-tight, it is accused, by the advocates of clay luting and others, of cracking under the slightest settlement, motion, or expansion of the pipe; and in some cases its use obliges the trench to be pumped dry, which is not the case with the Stanford joint.

Clay Joint

Good tough clay, well puddled, or, in other words, good clay puddle, is supposed to be impervious to water. Puddling consists in thoroughly beating up or tempering the clay with water and mixing with it some chalk, gravel, or sand, to prevent it from cracking on becoming dry. An interstice stopped by this substance is a clay joint, and brick sewers built in porous soils are surrounded up to half their height with a lining of puddle. Sewer-pipes are sometimes united with carefully tempered clay, which is considered by some superior to Portland cement for such purpose. The socket of each pipe is well daubed with it before laying, and the inside of the joint is worked solid and well smoothed after the plain end of the next is inserted. It is not so liable to crack under expansion or settlement, though it has been strongly denounced because of its soft, yielding character, which not only renders it liable to be washed out either by the sewage from the inside or the subsoil water from the outside, but endangers the maintenance of a straight line of invert through the weight of earth above the pipe squeezing the clay out of the lower part of some of the sockets. If the clay also at the upper part of the sockets dries, it becomes porous and shrinks, or tends to shrink, to the extent of 1/24 of its moist dimensions, but this refers to pure clay and not to puddle.