  The mechanical behaviour of porous sandstones is generally modelled using
concepts from granular mechanics, often overlooking the effect of cementation.
To probe the key differences between sand and sandstone mechanics, we performed
triaxial deformation experiments on Ottawa quartz sand at $5-40$ MPa effective
confining pressure. At $5$ MPa, the samples are able to dilate. At higher
confinement, the aggregates show continuous compaction, displaying strain
hardening. The stress-strain behaviour is non-linear and the exact onset of
inelastic compaction could not be determined accurately. Measured P-wave
velocities show the development of anisotropy. With increasing axial strain,
the along-axis velocities tend to increase, while velocities perpendicular to
the compression axis tend to decrease (at low pressure) or remain constant (at
high pressure). In samples deformed under elevated pressure conditions,
acoustic emission event locations are diffuse. Microstructural investigations
show an increase in grain chipping and crushing with increasing confining
pressure, but no evidence of localised compaction could be observed. The nature
of the pore-fluid, either decane or water, does not significantly influence the
mechanical behaviour at strain rates of $10^{-6}$ to $10^{-4}$ $s^{-1}$. Grain
angularity and grain-size distribution also did not significantly change the
mechanical behaviour. We infer that our observations indicate that the lack of
cementation introduces additional degrees of freedom for grains to slide,
rotate, and reorganise at the sample-scale, precluding the existence and
sustainability of stress concentrations beyond the grain-scale. This results in
progressive compaction and hardening, and lack of compaction localisation.
