Whether for shotcrete or TBM application solutions, CHRYSO offers a full tunneling range of products and services that meet your safety, performance and productivity needs.


CHRYSO tunneling expertise

Whichever tunneling method you use – Shotcrete or TBM methods – our full tunneling offering comprises innovative and proven-effective products for concrete and shotcrete (a wide range of admixtures, new generation accelerators, mould-release agents for precast and moving formworks, fibres for structural reinforcement and fire protection) and for filling grout (CHRYSO®TBM range).



Even when using the New Austrian Tunneling Method (NATM), the performances of sprayed concrete (shotcrete) are essential to guarantee the safety of personnels during the excavation and the durability of the tunnel for decades. Over the years, CHRYSO has developed a large expertise regarding the mix design, the dedicated technologies and the technical support necessary to achieve optimal shotcrete performances throughout the project completion.

TBM tunneling


Tunnel Boring Machines (TBMs) are used as an alternative to conventional mechanical excavation. CHRYSO provides a wide range of products for TBM application. Mechanized Tunneling is developing with the expansion of underground construction, particularly in urbanized areas.

BENEFITS from the CHRYSO tunneling offers

Safety of personnel

Concrete and backfill early strengths – Adapted backfill gelling time


Solutions adpated to your project specifications and local raw materials, delivering consistent results


High pumpability, high workability retention, consistency and durability

CO2 reduction

Raw material reduced and use of low CO2 binders

Shotcrete application

A large range of shotcrete accelerators dedicated to tunneling projects

CHRYSO offers a complete range of accelerators adapted to your building site constraints.

  • Low rebound rates
  • Compatibility with almost all spraying equipments
  • Fast strengths gain

Alkali-free accelerators are easy and safer to use.
Our accelerator range is compatible with all cements, they operate perfectly in synergy with CHRYSO®’s superplasticizers to provide very high early compressive strengths.

Shotcrete tunneling application
CHRYSO Superplasticizers


CHRYSO superplasticizers are designed to enhance the rheology of shotcrete and in particular, long workability retention.
CHRYSO®Optima 100 and CHRYSO®Optima 1000 ranges are especially suited for shotcrete applications:

  • Allowing concrete transportation over long distances and flexibility regarding waiting time on site.
  • Maintaining an excellent pumpability even when using fibres reinforced concrete.
  • Ensuring a very good cohesion of the concrete.
  • Enabling very high early compressive strengths
superplasticizers for tunneling construction
Structural reinforcement with macro-fibres


Combined with CHRYSO®Jet range of admixtures and our dedicated concrete mix-design know-how, synthetic fibres ensure a flawless and successful operation throughout the project.
Fibres dedicated to spray concrete are designed for:

  • Easy pumping
  • Maximum rebound reduction
  • Ultimate tensile strengths performance
  • Enhanced durability

As a part of its complete range of tunneling solutions, CHRYSO dedicated macro-fibres allow to meet the requirements of classes A, B and C shotcrete (EFNARC or ASTM standards).

Anti-fire spalling fibres

CHRYSO offers a full range of proven anti-fire spalling fibres and its expertise in adapted mix designs.

Tunneling structural reinforcement with macro-fibres


CHRYSO provides a wide range of products that are designed specifically for use with all TBM processes (ex: traditional or A +B backfill grouts)

CHRYSO®TBM for traditionnal backfill mortars


  • Pumpability enhancement
  • Workability retention
  • Strengths increase
  • Anti wash-out performances
Type A+B backfill grout

Supported by our wide network of local laboratories, CHRYSO local technical experts provide mix-design optimization and a wide range of dedicated products adapted to your project.

TBM tunneling
CHRYSO®TBM SGS: NEW smart grout system

First technology resulting from CHRYSO and CONDAT collaboration, CHRYSO®TBM SGS (Smart Grout System) is a cutting-edge
patented backfill grout solution which ensures exceptional grout stability over several days before placement.
The grout stability and low viscosity allow for pumping over long distance and reduce the need for pipes flushing during machine stoppages, delivering unparalleled performance to meet the most demanding jobsites.
CHRYSO®TBM SGS is using a combinaison of several specific admixtures.

New CHRYSO®TBM SGS solution provides high-performing environmentally-friendly backfill grout for tunnels and underground city projects, that significantly reduces tunneling construction site’s environmental footprint, thanks to bentonite substitution.

grout system for tunneling construction

  • High Pumpability
  • Outstanding stability
  • Gelling Time flexibility
  • Compressive Strengths

Tunnel segments expertise


CHRYSO offers precast concrete professionals and Major companies specialized in underground construction projects, a series of products and services dedicated to tunnel segments production.
CHRYSO®Tera stands out as it improves tunnel segments production performances thanks to dedicated admixtures and CHRYSO®Tera Lab tailor-made service.

In addition to the traditional performance indicators (slump retention, water reduction, workability, early strengths, etc.), our innovative approach focuses on 3 tunnel segments specific performance indicators:

  • Placeability (reduced time to fill the mold)
  • Leveling Easiness (improved extrado aspect)
  • Finishability (easier and faster finish of the extrado)
Tunnel segments

Specific range of mould release agents for concrete segments

CHRYSO offers a large range of demolding agents with an optimum HSE profile, enabling high quality surface finishes and preserving molds durability even at the most stringent curing temperatures.
With the help of our technical team, we can optimize the use of  release agents, optimize your nozzle choices, your consumption ratio, deliver additional cost savings and segments’ finish quality.

Fibres for tunnel segments

CHRYSO offers a full range of proven anti-fire spalling fibres and our expertise in adapted mix designs, especially for tunnel segments.
CHRYSO has developed a unique comprehensive know-how regarding Fibre-reinforced concrete (FRC), to improve the fire resistance and the durability of concrete.

tunneling concrete segment

Tunneling global service offer

CHRYSO offers a full tunneling range of services to meet your safety, performance and productivity needs.

Dedicated service for tunnel segments

CHRYSO teams will provide you with a tailor-made CHRYSO®Tera Lab, a dedicated service for tunnel segments, that will help you solve your Tunnel segments problematics and improve your production.

tunnel metro

Our R&D and technical teams support you to optimize shotcrete, tunnel segment and backfill grout mix design technical support to meet the requirements of classes A, B and C shotcrete (EFNARC or ASTM standards) for shotcrete.

In situ technical support: CHRYSO technical experts accompany you in situ to offer the most adaptable and best fit solutions to meet your specific requirements.

Chryso logistic chain

CHRYSO supports your teams throughout the logistic chain: both during equipment installation, training and daily supply.


Tunnel construction metro tunneling Paris
Infrastructures de transport


Le Grand Paris Express est le plus grand projet urbain en Europe. Il a pour ambition d’unir les grands territoires stratégiques de la région d’Ile-de-France, au premier rang desquels Paris et le cœur de l’agglomération parisienne

Voir la référence

Contactez nous

To learn more about the CHRYSO tunneling offer, contact us.

Contact FR