Page 466 - Trenchless Technology Piping Installation and Inspection

416 App endix D

is based on these six properties: (1) density of base resin (2) melt index
(3) flexural modulus (4) tensile strength at yield (5) ESCR (6) hydrostatic
design basis and color.
Cellar drain: A pipe or a series of pipes that collect wastewater which
leaks, seeps, or flows into subgrade parts of structures and discharges
them into a building sewers; by other means, dispose of such wastewaters
into sanitary, combined, or storm sewers. Also referred to as basement
drain.
Chemical grouting: Method for the treatment of the ground around a
shaft or pipeline, using noncementitious compounds, to facilitate or make
possible the installation of an underground structure.
Chemical stabilization: A repair method in which a length of pipeline
between two access points is sealed by the introduction of one or more
compounds in solution into the pipe and the surrounding ground and,
where appropriate, producing a chemical reaction. Such systems may
perform a variety of functions such as the sealing of cracks and cavities,
the provision of a new wall surface with improved hydraulic characteri-
stics or ground stabilization.

Chimney: The small vertical section between a manhole frame and cone,
which is built from brick, masonry, or concrete adjusting rings.
Chippers: See bits.
CIPP: Cured-in-place pipe; a renewal technique whereby a flexible
resin-impregnated tube is installed into an existing pipe and then cured
to a hard finish, usually assuming the shape of the existing pipe.
Circumferential: The perimeter around the inner surface of a circular
pipe cross section.
Circumferential coefficient of expansion and contraction: The fractional
change in circumference of a material for a unit changes in temperature;
expressed as inches of expansion or contraction per inch of original
circumference.
Closed face: The ability of a tunnel boring machine to close or seal the
facial opening of the machine to prevent, control, or slow the entering of
soils into the machine. Also may be the bulk heading of a hand-dug
tunnel to slow or stop the inflow of material.
Closed-circuit television inspection (CCTV): Inspection method using a
closed-circuit television camera system with appropriate transport and
lighting mechanisms to view the interior surface of sewer pipes and
structures.
Close-fit: Description of a lining system in which the new pipe makes
close contact with the existing defective pipe at normal or minimum
diameter. An annulus may occur in sections where the diameter of the
defective pipe is in excess of this.