Chryso TBM SGS (Smart Grout System) is a patented formulation resulting from the collaboration between France-based Chryso and TBM sealant and lubricants provider Condat.

The combination of Chryso TBM SGS 150 retarder and TBM SGS 400 stabiliser is designed to result in a low viscosity and high grout stability said to last over several days. This is claimed to allow the product to be pumped over long distances and reduces the need for pipe flushing during machine stoppages, thereby improving the performance of TBM tunnelling.

Reducing the tunnel site’s environmental footprint and aiding better environmental management are also claimed benefits of the product: by completely replacing bentonite (commonly used in backfill-mix design and also non-renewable), there is no need to transport or store it.

“We are bringing a high-performing, environmentally-friendly backfill grout for tunnels and underground city projects,” said Marc Plançon, Concrete Business Unit Deputy Director at Chryso.

Thierry Sanna, Sales Director, Tunnelling Division at Condat, said: “This first collaboration on the Smart Grout System has given significant results and we are looking forward to further successful development of innovative solutions.”