ABSTRACT
A high-performance backfill grout has been developed as a crucial component of the new tension-resistance single-pass segmental lining solution that will be adopted for building the Inclined Pressure Shaft (IPS) of Snowy 2.0 Pumped Storage Hydropower project. The mix was validated through an extensive testing campaign which, in addition to the mechanical and cyclic tests made to verify its strength and fatigue behaviour, included two tailored tests to verify its erosion and abrasion resistance and ensure its integrity bear no significant degradation during expected transients. The major challenge was to simulate the exposure conditions expected during transients, such as rapid water flows through lining drains and the cyclic friction generated between backfill fractions due to lining deformation, which was not possible to represent adopting the conventional test set-ups available. This paper describes the two tailored tests on backfill and discusses the encountered challenges and obtained results.
