Authors: Sainsbury, BL; Harty, D; Felipe, F; Ruest, M; McLoughney, D; Sainsbury, D

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Sainsbury, BL, Harty, D, Felipe, F, Ruest, M, McLoughney, D & Sainsbury, D 2024, 'Characterisation of the geomechanical properties of cemented paste backfill for design', in AB Fourie & D Reid (eds), Paste 2024: Proceedings of the 26th International Conference on Paste, Thickened and Filtered Tailings, Australian Centre for Geomechanics, Perth, pp. 385-394,

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This paper documents an investigation that has been conducted into the influence of pulp solids and cement content on the unconfined compressive strength (UCS), modulus and tensile strength of cemented paste backfill. A laboratory testing program has been conducted that includes in excess of 500 tests to provide a series of relationships that consider: In relation to the modulus, existing literature has been used to relate laboratory-scale tests to field-scale values that are able to account for the enhanced mixing during placement underground, higher in situ curing temperatures and consolidation within the stope due to the increasing overlying fill mass during curing (Thompson et al. 2012). Direct tension values have been measured directly via a bespoke method that has been modified based on a technique outlined in Guo et al. (2022) and Pan & Grabinsky (2021). While there are many studies that propose relationships for cemented paste backfill that characterise density, UCS and modulus, none are completed on such an extensive database or provide direct tension values over such a broad range. The relationships presented provide guidance for pre-feasibility or optimisation studies associated with cemented paste backfill.

Keywords: cemented paste backfill, geomechanical testing, direct tension, modulus, unconfined compressive strength

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