Characterisation of thefine particlesFromexperience we knowthatclays"react"with water. They are hard and stiff when dryand muddy when wet.Wealsoknowthat not each clay reactsthesame.Sensitivity of fine grained materials to changesin moisture content is determined by means ofplasticity (viscosity/consistency)tests.The liguid limit and plastic limit are calledAtterberg's limits.11August31,2025ATUDelft
August 31, 2025 11 Characterisation of the fine particles • From experience we know that clays “react” with water. They are hard and stiff when dry and muddy when wet. • We also know that not each clay reacts the same. • Sensitivity of fine grained materials to changes in moisture content is determined by means of plasticity (viscosity/consistency) tests. • The liquid limit and plastic limit are called Atterberg’s limits
Atterberg limitsDeterminedonmaterialpassingNo4osieve(425 μm)12August31,2025TUDelft
August 31, 2025 12 Atterberg limits • Determined on material passing No 40 sieve (425 m)
Soil phases and Atterberg limitsSOLIDSEMI-SOLIDPLASTICLIQUIDSUSPEN-PhaseSTATESTATESTATESTATESIONWater content decreasingWaterLimitsDryShrinkageLiquidsoilLimitLimitLimitSLPLLLPlasticity IndexPIVolumeVolumedecreasingShrinkageconstantHard toMater-heldConditionWorkableStickySlurrystittisuspensionShearShear strength increasingStrengthNegligibleto nil(kN/m2)(~170)(~1.7)MoistureSLPLOLLContent上P1H13August3TUDelft
August 31, 2025 13 Soil phases and Atterberg limits
Casagrande device for liguid limit(LL) assessmentlockingscrew-locknutpivotHi-adjustingscrewUcamUe-follower10mmdirection/ofrotationbasehandle(a)(b)August31,202514NTUDelft
August 31, 2025 14 Casagrande device for liquid limit (LL) assessment
Liquid limit can also be determined bymeansof penetrometertest-HollowstemMassofGaugeplateassemblyLead shot80.00g5mm30°Worntip35mm1.50mmdiaab15August31,2025TUDelft
August 31, 2025 15 Liquid limit can also be determined by means of penetrometer test