Witteman, M & Simms, P 2010, 'Hydraulic response in cemented paste backfill during and after hydration', in R Jewell & AB Fourie (eds), Paste 2010: Proceedings of the Thirteenth International Seminar on Paste and Thickened Tailings
, Australian Centre for Geomechanics, Perth, pp. 199-207, https://doi.org/10.36487/ACG_rep/1063_17_Witteman
The distribution of pore-pressures in mine stopes may have important implications to the design of cemented
paste backfill (CPB) systems. Self-weight consolidation after filling stopes is inherently problematic when
pore-water pressures begin to develop. However, during cement hydration, self-desiccation begins to occur
and consequently, pore-water pressures gradually dissipate. In some cases, during self-desiccation, matric
suctions can develop within stopes, depending upon adopted mining strategies such as, fill rate and percent
water to binder content. Tracking the evolution and quantifying the hydraulic behaviour in cemented paste is
rather difficult because of the complexity of the hydrating material. The current study investigates and
attempts to capture CPB’s transient responses during and after cement hydration through a series of self-
desiccation tests and axis translation tests. Self-desiccation tests are conducted on cemented paste specimens
containing 0, 3, 5 and 7% wt binder material. The water-retention properties of the material are measured
without binder, and after 28 days of hydration. This data is then used to approximately model the dissipation
of pore-water pressures measured at the bottom of stope during a plug pour. The approach shows promise.
Significance and future improvement to the proposed methodology are discussed.
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Hydraulic response in cemented paste backfill during and after hydration M. Witteman and P. Simms
208 Paste 2010, Toronto, Canada