Page 175 - Trenchless Technology Piping Installation and Inspection

Pipe and Pipe Installation Considerations 141

• Pipe physical and chemical properties.
• Availability of diameter sizes, pipe section lengths, and joints
(specifically for trenchless technology).
• Construction and operational stresses in the pipe. In many
cases for trenchless technology projects, the construction
stresses in the pipe exceeds the operational stresses.
• Location and pipe environment (inland, offshore, in-plant,
corrosiveness of soil, and so on).
• Type of burial or support (underground, aboveground or
elevated, underwater, and so on).
• Hydraulic properties of the pipe.

4.6 Rigid Pipes
The following sections present main types of rigid pipes.

4.6.1 Cement-Based Pipes
Pipes in this category include concrete pipe as well as asbestos-cement
pipe. Both types incorporate portland cement as the base material.
Concrete pipes are designed with or without reinforcements and are
used for both pressure and gravity applications. Asbestos-cement
pipe is composed of a mixture of portland cement, silica, and asbestos
fiber and was used in North America mainly in potable water appli-
cations, though many sewer systems also have asbestos-cement pipes
in service. Asbestos-cement pipes have not been manufactured or
installed in the United States since the late 1980s, but large quantities
of the pipe continue to be in service in water systems at various
locations. It is therefore important for engineers to have a working
knowledge of the properties of this material. Both concrete and
asbestos-cement pipes are rigid conduits and are accordingly designed
for installation.
Concrete Pipes
Trenchless construction with concrete pipe was first performed by
the Northern Pacific Railroad between 1896 and 1900, when the pipe
was installed by jacking. The jacking of concrete pipe is performed
both for pressure and gravity applications. Concrete pressure pipes
are also installed by tunneling methods. For small-diameter pipe in
short tunnels, such as those under a highway or a railroad, it is a com-
mon practice to slide the pipe through a liner followed by grouting
the interspace.
Manufacturing Concrete pipes can be made with any of the five types
of Portland cement. There are five manufacturing processes used in
North America, four of which use mechanical means to place and