CEMP-E
EI 11C201
1 March 1997
o-ring gaskets, or tongue and groove type made with cement mortar or bituminousmastic.
Design of concrete sewers will be in accordance with the Concrete Pipe Handbook by the
American Concrete Pipe Association. The Concrete Pressure Pipe Manual, Manual No. M9
published by the American Water Works Association (AWWA) will be used for design of force
mains.
(1) Type II A cement, as specified in ASTM C 150, is sufficient for most installations.
Type I may be used in certain situations where less than 0.1 percent soluble sulfates (S0 4) occur
in the soil, or the wastewater contains less than 150 mg/L sulfates. If the soil contains more than
0.2 percent water soluble sulfates, or the wastewater sulfate concentration exceeds 1000 mg/L,
Type V cement will be required. Unlined concrete pipe is subject to scouring by wastewaters
carrying grit and sand at high velocities.
(2) Non-reinforced concrete sewer pipe is generally available in diameters 100 mm
(4-inch) through 750 mm (30-inch), and in minimum laying lengths of 1 m (3 feet). Pretensioned
reinforced concrete pressure pipe is available in diameters 250 mm (10-inch) through 1,050 mm
(42-inch), prestressed concrete pressure pipe in diameters 400 mm (16-inch) through 3,600
(144-inch), and reinforced concrete (R.C.) pressure pipe in diameters 600 mm (24-inch) through
3,600 mm (144-inch). Each type utilizes bell and spigot joints with rubber gaskets. Reinforced
concrete pipe will be used where high external loadings are anticipated, and large diameters or
tight joints are required. The advantages of R.C. sewer pipe include a wide range of diameters,
300 mm (12-inch) through 2,700 mm (108-inch), and laying lengths, 1.2 meters (4 feet) to 7.3
meters (24 feet), which are available.
f. Plastic. Characteristics which make plastic pipe highly desirable include high corrosion
resistance, light weight, and low coefficient of friction. Disadvantages include the possibility of
excessive pipe wall deflections when installed improperly or subjected to high temperature
wastes, and chemical breakdown caused by prolonged exposure to sunlight. Manufacturer's
recommendations will be used in design of plastic pipe systems (especially in checking
deflection, backfilling and trench loads), in addition to the Handbook of PVC Pipe-Design and
Construction published by the Uni-Bell PVC Pipe Association. Allowable pipe deflections will be
indicated in the project specifications. The following types of plastic pipe are suitable for use:
- Polyvinyl chloride (PVC)
- Acrylinitrile butadiene-styrene (ABS)
- Polyethylene (PE)
- High density polyethylene (HDPE)
g. PVC. PVC pipe is suitable for gravity sewers or forcemains. It is chemically inert to most
acidic and alkaline wastes, and is totally resistant to biological attack. Since it is a nonconductor,
PVC pipe is immune to nearly all types of underground corrosion caused by galvanic or
electrochemical reactions, in addition to aggressive soils. Durability, light weight, a high
strength-to-weight ratio, long laying lengths, watertight joints and smooth interior surfaces are
characteristics which make PVC pipe an attractive alternative for use in sewer systems.
Disadvantages include possible chemical instability due to long-term exposure to sunlight,
excessive pipe deflection under trench loadings when installed improperly or subjected to high
temperature wastes, and brittleness when exposed to very cold temperatures. PVC pipe must
be installed to provide continuous passive lateral soil support along the conduit, and the
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