Grouting additives

Grouting additives
Grouting additives to secure the tunnel excavation.


Filling grout is a key element in the safety of tunnel excavation. It limits  settlements by filling the annular gap left between the cutting diameter and the extrados surface of the segments. It limits cave-in by filling the annular gap left between the cutting diameter and the external diameter of the segments.

Correct filling of the annular gap:

  • ensures good cohesion between the ground and the segments
  • aids guiding of the machine when fixing the segments

The most commonly used technology today is bi-component grouting which offers numerous logistical advantages:

  • Availability of the grout by continuous feed,
  • Pumping of the grout from the surface,
  • The grout can be pumped for up to 72H, etc.

CONDAT offers:


Product benefits

The grouting additives offered by CONDAT enter into the composition of bi-component and traditional grouts

Condat A Stabilizer L

Incorporated in the A mix, it has the following advantages:

  • greater fluidity (long-distance pumping)
  • greater stability (limits bleeding)
  • delayed setting and blocking of cement hydration
  • low environmental impact

Condat B Accelerator

Hardener added to A mix on injection into the annular gap; it provides:

  • gelling of the A mix
  • rehydration of the cement
  • early-age strength development

Associated services

For each project, CONDAT carries out appropriate studies in its dedicated laboratory. These analyses allow our experts to develop the best grouting formula based on given specifications. They can also bring assistance for the grouting implementation  and train the teams in charge of production and grouting control on site.

For more information about the products, their implementation, and a good match between the situation encountered and the solution to be envisaged, contact a CONDAT representative.