Injection technology

Injection methods

There are five main injection methods:

  • high-pressure injection;
  • low-pressure injection;
  • crack filling by pouring or dripping;
  • gravity-fed/penetrating injection;
  • vacuum injection.

 

Depending on the type of materials used, injection methods are divided into:

  • injection of chemical substances;
  • injection of synthetic substances;
  • injection of solid substances. 

The first three methods are the most common among renovation methods and will be described in more detail below.

 

Injection types

The main types of injection are the following:

  • sealing injection;
  • rigid bond injection;
  • elastic injection;
  • filling injection.

 

Fields in which injection technology is used

Injection material most commonly used in dam construction is cementitious slurry. This material helps reduce groundwater percolation or prevent the unwanted water pressure in the pores and soil erosion under the dam structure. 

In tunnel construction (train, street, subway tunnels, power plant shafts), injection technology is used to reduce strong groundwater percolation, reinforce stirred soil or prevent the decrease in groundwater level.

In civil construction, where water causes damage to the structures (walls, ceilings, floors), injection can be used to seal or reinforce such structures.

 

Waterproofing of concrete elements

This is particularly relevant in waterproofing of buildings.

Internal or external rigid bond or elastic sealing systems can be used for waterproofing. Their choice depends on the customer’s or contractor's wishes, the idea behind waterproofing and the experience of installers. In conjunction with waterproof concrete, the following systems are used most often (depending on the sealing problem): injection hose (most often multiple injection), seam tin-plate, seam tape, EPDM, PVC, HPDM film, Hypalon cold-process bitumen layer, thick-film systems, whole surface insulation systems, rubber or bentonite swelling tape (their popularity has recently decreased).

 As previously mentioned, preventive waterproofing systems are suited for different applications; therefore, the appropriate choice taking into account the use, method and implementation is very important. It should be noted that although in theory most systems function well, they are complex and costly and their performance to a large extent depends on the skill and experience of the installers, installation conditions (e.g. clean surface) and limits on working time and temperature. The temperature, dew point and relative humidity can impede the performance even for an experienced specialist and this may lead to leakage problems in the future.

 Our sealing solutions are based on the analysis of the particular case: taking into consideration the wishes of customers, together we discuss the possibilities of waterproofing and agree on possible combinations of systems.