Concrete pipes are pipes made from concrete. They provide various advantages including, easy installation, superior corrosion resistance, highly durable, environmentally friendly, sustainable, custom-designed fittings, high strength, and low maintenance costs. Because of all these benefits, concrete pipes have become a popular choice for Storm Sewers, Culverts, Underground Detention and Retention Systems, Sanitary sewers, and sometimes water pipelines. In this article, we will discuss concrete pipes, their types, and their applications.
What is a Concrete Pipe?
Concrete pipe is a rigid pipe having very good strength and high longevity (life in the range of 70 to 100 years). They are suitable for various loading conditions and are designed and manufactured based on ASTM C-76, AWWA, and AASHTO M 170. Concrete pipes are being used for a long time mainly in the water and wastewater industries. The oldest known concrete pipe used in a sanitary sewer in the United States (Mohawk, New York) is a 6-inch diameter pipe that is still operating successfully (Reference: https://www.rinkerpipe.com/TechnicalInfo/files/InfoBriefs/IB1003LifeConcretePipe.pdf).
Types of Concrete Pipes
There are four types of concrete pressure pipes found in industries. they are:
- Prestressed Concrete Cylinder Pipe (PCCP)
- Reinforced Concrete Cylinder Pipe
- Reinforced Concrete Non-Cylinder Pipe
- Pretensioned Concrete Cylinder Pipe
Prestressed Concrete Cylinder Pipe (PCCP)
Prestressed concrete cylinder pipes have a structural, high-strength concrete core, a steel cylinder with steel joint rings welded at each end providing water-tightness, steel prestressing wire, and a portland cement-rich mortar coating. They are usually manufactured in the range of NPS 16 to NPS 144.
This is the most widely used type of concrete pressure pipe for the transport of water and wastewater in the world. Their typical use includes
- Water distribution systems,
- Raw and potable water transmission lines,
- Gravity and pressure sewers,
- Industrial process lines,
- Power plant cooling systems,
- Water and wastewater treatment plant process lines,
- Impoundment spillway conduits
- Sewer outfalls,
- Raw water intakes, etc
PCCP is suitable for both freshwater and seawater and can be installed in the normal direct-buried condition; as an aerial crossing over canals, rivers, and other obstacles. AWWA C301/C304 provides the design and manufacturing reference for PCCP.
Reinforced Concrete Cylinder Pipes (RCP)
Reinforced concrete pipes are widely used in roadway and site development for transferring a large volume of liquid. They are produced in the size range of 12″ to 144″. Typical applications of reinforced concrete pipes include:
- Irrigation Industry
- The construction industry for the transfer of non-potable water underground.
- City waters in a Storm drain, flooding situation, monsoon water.
In general, reinforced pipes are precast. AWWA Standard C300 provides the design and manufacturing guidelines for RCP pipes.
Reinforced Concrete Noncylinder Pipes
AWWA Standard C302 provides the reference for reinforced concrete non-cylinder pipes. AWWA Manual M9 provides the design guidelines for this type of concrete pipe. One or more reinforcing cages are used along with steel joint rings to manufacture reinforced concrete non-cylinder pipes. They are generally used for a working pressure up to 380 KPa. These concrete pipes are widely found in tunnel applications, wastewater treatment plants, irrigation industries, combined sewer overflow, underground detention tanks, etc.
Pretensioned Concrete Cylinder Pipe
AWWA Standard C303 provides the refernce of Pretensioned Concrete Cylinder Pipes. They are also known as bar wrapped concrete cylinder pipes. The interior of the pipe is provided with with centrifugally applied mortar or concrete lining. Around the outside of the cylinder, a steel bar is helically wound tightly and securely welded to the steel joint rings. Next, a cement-rich dense mortar coating is applied to the cylinder and bar wrap. These types of concrete pipes are used in cooling water system pipelines, distribution pipelines, open cut tunnels, sanitary main and trunk gravity lines, wastewater intake lines, etc.
Advantages of Concrete Pipes
As already mentioned, concrete pipes are highly durable and strong pipes. Other benefits of using concrete piping are:
- Highly resilient
- Low cost
- Easy installation
- Design and Construction flexibility
- Weather resistant.
- Corrosion resistant.
- Can resist both tensile and compressive stress.
- Can be cast in situ.
- Suitable for all types of water.
However, concrete pipes can be corroded at the crown by the bacterial decomposition of organic matter present in sewage. Also, they are heavy and transportation and installation costs may be a bit higher.