Concrete Pipe
Concrete Basics
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pipe has a well established history and reputation for being a long
lasting, serviceable material. The Cloacae Maxima, built in about
180 B.C. as part of Rome's main sewer system, was constructed mainly
of stone masonry and natural cement concrete. More than 2000 years
later, portions of the concrete sewer are still in use.
Modern day concrete pipe sewer systems emerged during
the mid-19th century when the public became conscious of the need
for sanitation to control the spread of disease. The earliest recorded
use of concrete pipe in the United States is a sewer installation
built in 1842 at Mohawk, N.Y. Other New England cities followed
suit and installed concrete pipelines in the second half of the
nineteenth century. Many of these concrete pipelines are still in
use today.
Milestones in concrete pipe development include the
production of the first reinforced concrete pipe in 1905, the invention
of prestressed concrete pipe in the 1930s, and the manufacture of
the first steel-cylinder prestressed concrete pipe in 1942.
 Concrete
pipe comes in many shapes and sizes. Concrete pipe sizes can range
from 4 inches (10 cm) up to 17 feet (5 m) in diameter. Although
concrete pipe can be manufactured in a variety of shapes, there
are five standard shapes: circular, horizontal elliptical, vertical
elliptical, arch, and rectangular. The pipe shape selected for a
project depends on the topography of the site, importance of hydraulic
and structural efficiency, erosion and deposition in the stream
channel, and cost. Most often, the preferred pipe shape is the one
that will alter the natural drainage flow the least.
Five Methods
As with all concrete products, the basic materials of concrete pipe
are portland cement, aggregate, and water. There are five basic
methods of producing concrete pipe. Four methods-centrifugal/spinning,
dry cast, packerhead, and tamp-entail using a dry concrete mix.
The fifth method, wet casting, uses a high-slump concrete mix. Wet-cast
concrete mix usually has a slump less than four inches and is most
frequently used for manufacturing large diameter pipe.
Concrete pipe serves as a conduit material for irrigation,
water supply lines, sanitary sewers, culverts, and storm drains.
Culverts, usually made with arch-shaped concrete, are used to carry
water under highways in non-urban areas. Storm drain systems for
cities and towns are becoming more important as communities become
larger and more densely populated. Recent major floods and the resulting
damage only emphasize the need for efficient drainage systems.
Subsurface drainage carries away water below
the surface of the pavement. This water reduces flow support capacity
of the base and subgrade material causing potential damage to roads,
airport runways, and building foundations. Many farm fields depend
on proper underground drainage for their cultivation. Thousands
of square miles of otherwise arid land rely on concrete irrigation
pipe to supply water for farmland. Additionally, most of the large
cities in the United States a concrete pipe system to transport
their water supply.
More information at the American
Concrete Pipe Association Web site. |