What differences are there between using concrete and plastic piping for wastewater systems and pipelines?

Concrete piping has, at least, the same water-related properties as smooth plastic pipes. All types of wastewater piping in service have the same Manning “n” coefficient, whatever the material they are made of. Nevertheless, the use of concrete in the manufacture of wastewater piping entails a number of advantages compared to the use of other materials:

Bearing capacity
The mechanical behaviour of concrete pipes very much depends on how they are installed, as the load resistance is very high with concrete. Reinforced concrete pipes are resistant in themselves.

Stability
Reinforced concrete pipes are structurally stable. Once installed, their own weight keeps them in place, so a little settling of the soil and the thrust exerted by the water does not affect them.

Resistance to physical deterioration
Abrasion is a physical phenomenon that occurs in all types of piping. All wastewater systems require cleaning processes with pressurised water to remove deposits. Concrete piping is much less affected by abrasion and is not damaged by the cleaning processes.

Thermal stability
Reinforced concrete pipes are resistant to fire, the action of UVA rays and high temperatures

Safety
A wastewater system must be watertight. Reinforced concrete pipes are designed with joints that guarantee water tightness using elastic gaskets.

Sustainability
Plastic piping is manufactured with starting materials coming from petroleum, while concrete pipes are made with natural substances that do not harm the environment, and that can be integrated into the environment without causing any damage after the concrete is crushed into gravel.

In addition, they consume much less energy and resources in their manufacture, and they are easier and less costly to recycle.

Economic costs
Price is a deciding factor when choosing between several valid solutions. The costs have to be evaluated as a whole. The cost of amortisation for concrete piping is less than for plastic, as is lasts at least 40% longer than plastic piping.

Plastic wastewater systems are less reliable than those made of concrete, as their structural integrity and guarantee of water tightness are lower, so the expenditure in maintenance is therefore greater. Reinforced concrete pipes allow short- and long-term savings.