Hallbom, DJ 2005, 'The “Lump” Test', in R Jewell & S Barrera (eds), Proceedings of the International Seminar on Paste and Thickened Tailings
, Australian Centre for Geomechanics, Perth, pp. 73-97, https://doi.org/10.36487/ACG_repo/563_5
The slump test, a standard test for concrete, has been adopted as a common
test for paste and thickened tailings. While the slump test is nominally quantita-
tive (i.e., it gives a value for slump in millimetres), it measures a vaguely defined
qualitative parameter (“workability”). To make the test more useful for design
purposes, it is desirable to relate slump to measurable physical parameters, par-
ticularly the slurry density and the apparent yield stress. For laboratory work, the
cylinder slump test has been found to be more practical than the cone slump test,
mainly due to the smaller test sample size. The Cylinder Model often used to
correlate cylinder slump and yield stress has been shown to be consistent with
vane test results for moderate to high relative slumps. However, at lower relative
slumps the Cylinder Model consistently underestimates the yield stress. This pa-
per discusses a variety of concepts relating to the rheological interpretation of the
slump test. It also presents a semi-empirical model (the “Lump Model”) that
extends the correlation range of the Cylinder Model and is simpler and easier to
74 Paste 2005, Santiago, Chile
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