Transport Recommendations

The road transport requires open trucks which are suitable for this type of material. Vehicles must be suitable to transport and loading and unloading operations of the tubes. It should meet the following basic rules:

  • Avoiding the friction between the pipes and fittings in order to avoid damage to the coating;
  • To avoid any direct contact of the tubes with the truck floor (keeping the flatness of the tubes with the aid of appropriate support bases, metal or wood surface lined with rubber, fixed on the floor);
  • To facilitate the loading and unloading of the tubes in a safe condition (using straps or hooks coated rubber);
  • Attaching the load with the aid of textile straps.

recomendações de transporte dos tubos de betão

Discharge on work

The discharge of the elements should be performed by means of suitable cranes to the weight thereof, using textile straps.

In case of impossibility to place the element in its final location, it must be deposited in a free surface elements likely to damage the pipe surface (such as stones, irons, etc.) and above all deposited in a non-compacted ground, the more indicated would be the closest support 90 degrees. It is essential to avoid contact of the mouthpieces with the ground in order to avoid deterioration of the primary or changing its geometric characteristics.

Descarga na obra de tubos da Alentubo

Assembly “in situ”

When mounting the pipe, it must take into account the type of coupling between tubes (elastic or welded) and the type of support chosen to withstand the elements (granular 90º or concrete to 120th).

After opening the trench, followed by the compression of the base . This aspect is particularly important because this will be the basis of the whole structure. This base shall support the pipe load, the fluid itself landfill and even if necessary, changing loads, without giving rise to differential settlement. If produce settlements, they may introduce unforeseen effort during the design as well as the change in the expected angular deflection. In this case, the cohesion of the ground is not uniform along the line path, the zones of weaker cohesion should be strengthened with appropriate materials to meet the grazing requirements. On the other hand, if the trench in rocky developing zone, it must be ensured that the tube is safe from any protuberance, to avoid damage during assembly.

The base width of the trench should have at least the outside diameter of the tube 2 x 50 cm, in order to simplify the inert deposition process as well as its proper compression.

The material chosen for the landfill should be selected so that it is free of rocky debris or other gender. This material will be deposited in layers alternately, and a compacted and across the tube, thus avoiding deviations from the duct axis. The compaction should be carried out with a slight compression of material, such as vibration plate, or other, using water as adjuvant.

Above 30 cm of of the pipe, these special requirements make no sense, so can the landfill be filled according to the normal.


Installation of pipelines in granular support 90 °

apoio granular a 90

Never compress with vibration up to 2m from the generator Superior

In this type of assembly, the inert choice for the tube bed utmost importance, since this is expected shape so as to accept the tube so that the load generated by it can be evenly distributed, without producing unexpected bending or angular deflections in couplings. Therefore, the most suitable material for this purpose would be a reduced grained sands with an inert maximum dimension of 20 mm.

After opening the trench (slope advisable to 1/3) and compacted at its base, it is necessary to carry out the leveling verification as to be in accordance with the longitudinal profile of the project. The granular material is distributed in order to reach a height of 0.15 x øext. Then the tube is carefully supported so it forms a cot and the tube is fully supported. If rules are being complied with, the environment of the elements will be in a state of primary stability, forming an angle of 90 ° between the axis of the conduit and the surface of the last layer.

Subsequently, the trench is filled and compacted with mild machinery, up to 60 cm above the top of the pipe in the form alternating layers of either side of the tube to minimize rotations or displacements.


– Never directly compress the tube to be at least 1.0 m above the generatrix of the tube.

– Never vibration compacting the tube to be at least 2.0 m above the generatrix of the tube.

To obtain a more efficient compaction is to be expected 7 days, to begin a new filling process, and should be irrigated during this period is abundant form the layer in question. Finally suffice to cover the rest of the ditch as set out in the project.

Assembly of conduits to support the concrete 120 °

apoio granular a 90

After opening the ditch (with recommended slope 1/3), the basis of this is filled with concrete in order to conform to the slopes provided in the project. After the curing time, placed the supports (concrete or wood) in the ends of the pipe, making sure that are available 12cm free below the lower generatrix, so that the next layer of concrete (more plastic characteristics), can flow beneath the pipe. Analogously to the above process, the concrete volume will be such so as to form the angle of stability, this assumes that the value of 120 °. For this to succeed must perform to concreting up to a height of 0.25 x øext. The fill the rest of the trench is made in layers by carrying out the compression without the use of vibration. This layer should reach 60 cm above the upper generatrix. Finally, fill the remaining space of the trench, without that layer exceeds the height of 30 cm.


– Never directly compress the tube, at least 1.0 m above the generatrix of the tube.

– Never vibration compacting the tube, at least 2.0 m above the generatrix of the tube.


Deflection angle and elastomers

In the creation of tubes, Alentubo takes into account the spacing of the free surface of the mouthpieces, their size and the elastomer used for the maximum angular deflection possible. The diameter of the elastomer is of varying diameter depending on the diameter of pipe to be applied (the most usual is 20 or 22 mm).