Tunnel excavation using EPB-TBMs has achieved remarkable productivity due to advancements in TBM design, highly effective soil conditioning products, improved backfilling grout techniques, and more. The chemicals used in EPB have pushed this tunnelling method to its highest performance levels in history. Despite these technical achievements, TBM operations still require substantial water, largely driven by soil conditioning—especially in cohesive ground formations. The amount of liquids (pure water and water for foam) used for soil conditioning can reach up to 40-45% of the excavated soil volume. Reducing this water demand is essential for more sustainable tunnelling, as water is a vital resource for communities and the environment.

New conditioning agents from the MAPEI ECO WSP (Water Saving Program) line offer a solution, reducing liquid requirements by approximately 25-35% without compromising soil conditioning performance. This improvement has been validated through extensive testing at the laboratory of the Politecnico di Torino and initial applications on TBM sites. Reducing water use—especially pure water—saves thousands of tons of water in tunnel excavation, providing multiple benefits: technical, economic, and environmental.

Lower water usage means reduced tunnel muck volume and fewer trucks needed to transport it, resulting in lower CO₂ emissions due to scaled-down logistics. These advantages are especially important today, particularly in regions where water is a precious resource. These new conditioning agents represent a key step forward in sustainable tunnel construction. For further information Mapei UTT, Milan, tel +39-02-37673073, email hq.utt@utt.mapei.com. Visit https://utt.mapei.com/en/home-page  45/24.