The manholes, either manholes, drop manholes or to incorporate connections, help to do simpler the exploitation and maintenance works of sanitation networks. The chambers have the same function, although some manholes, unlike the chambers, they can be visited. The installation can be in the same place, what it is known as “insitu” construction, or with the prefabricated. According to the materials they can be made of, most common manholes are of concrete (either in mass or built), brick and plastic materials.

pozos-de-plástico

The aim of this text is to know the differences between concrete and brick manholes and the ones of plastic materials:

Installation

The simplicity and ease of installation of the manholes with plastic materials has a positive point. With them, it is not necessary to use heavy machinery for the transportation or a great number of workers, what means a reduction of the cost in comparison to the concrete manholes.

For these, the heavy machinery is obligatory. For example, concrete manhole which is 1 metre in diameter and 2 metres high reaches 2.5 tons weigh.

Adaptability and flexibility

While in the concrete and brick manholes any movement or vibration in the soil can produce a break in the body or in the rigid join that there is in the pipe connections; in the plastic manholes both the adaptation to the soil as its flexibility play in their favour. Its solvency has been demonstrated even in the case of important seismic disturbances.

Resistance

The concrete and brick manholes don’t assure the resistance to the effect of the waste waters that can corrode the walls due to the agents they have. However, the manholes built with plastic materials assure the resistance to salts, acids and other materials which are present in the waste waters and that can be harmful for the environment.

The concrete neither guarantees the resistance of the walls and the bottom to chemical products or leachates, while the plastic materials are capable of supporting chemical waste and of landfills so they are ideal for the evacuation of waste waters.

Tightness

The concrete and the brick can suffer water infiltrations of the soil, or leaks, what would suppose the arrival of waters, in occasion waste waters in the soils they are. The plastic, on the contrary, guarantees that there are no leaks due to porosity or cracks and avoids the infiltration through the walls, what assures the tightness for life.

Maintenance

The roughness of the concrete plays against it as it is necessary to clean periodically this type of manholes due to the components of the liquids and solids which are dragged by the waste waters and which can remain in it.

The plastic materials of the manholes have an internal flat surface, without any type of roughness or corners. Although they have slopes towards the outlets which allow a good flow of the liquids.