Wall friction

Coefficient of wall friction for the determination
of pressures is determined in the Jenike shear tester. The reference
stress is equal to the horizontal silo pressure. Test procedure
follows recommendations of the Eurocode 1 design standard.
Angle of wall friction for the evaluation of flow is determined
with the tilting table method under the reference stress as low
as possible to simulate the low pressure occuring during discharge
near the outlet of the silo.
Internal friction

The angles of internal friction and effective
angle of internal friction and cohesion are determined in the Jenike
shear tester. Test procedure follows recommendations of the Eurocode
1 design standard.
Pressure ratio

The pressure ratio is determined in the uniaxial
compression test. The tester measures the horizontal stress. Test
procedure follows recommendations of the Eurocode 1 design standard.
Elasticity

The modulus of elasticity and the Poisson's ratio
are determined in the uniaxial compression test from the linear
part (BC) of the unloading curves: vertical stress-strain and horizontal
stress-vertical stress. The tester measures the horizontal stress.
Propagation of accoustic waves in granular materials

Experimental set allowed for generating and recording
of shear waves. Values of elastic constants are determined based
on measurement of shear wave velocity. Velocity of acoustic shear
wave is determined in chamber fitted with piezoelements in top and
bottom cover.