ABSTRACT
The two-component grout is the backfilling technology more frequently used in tunnelling construction where shielded machines are adopted. Despite its intensive use, different aspects of the technology have not been deepened sufficiently, particularly concerning the role of the two-component grout in the waterproofing of the tunnel. In fact, despite in scientific literature the engagement of the two-component grout in the protection of assembled linings against the water inflows is often mentioned, no proofs of this ability are available. Furthermore, in case of presence of water, the freshly injected two-component grout may be washed out reducing its thickness and, consequently, its waterproofing capacity but also this aspect have never been investigated. In this work, the impact of water on the fresh two-component grout is studied in laboratory by using an innovative apparatus, expressly designed and realised for the purpose. A test procedure is introduced and preliminary obtained outcomes highlight the aptitude of the grout to exhibit the washing-out resistance.
