Mass of water: M2- M3=7.05g
Mass of dried soil: M3- M1=23.20g
Wn=30.4% (3sf-in compliance with NZS 4402)
Wn=30% (to nearest whole number)
All guidelines within the NZS 4402 methodology were adhered to as closely as possible: The tin base and lid were both cleaned and dried prior to weighing (to the nearest 0.01g), while handling the soil, dry, clean hands we ensured in order to avoid altering the water content of the soil and it was also stored within a ‘sealed’ tin container during the weighing process to further eliminate any un-accounted water loss.
Liquid Limit Test (N.Z.S. 4402 Test 2.2)
All guidelines within the NZS 4402 methodology were adhered to as closely as possible. At all times, the soil sample was kept under a plastic sheet in order to minimise its moisture loss due to the heat of the students, each soil sample was thoroughly compacted/consolidated within the brass cup of the Casagrande apparatus in order to minimise the presence of any air voids and an attempt was made to maintain a drop frequency of 2 per seconds (although there was some tendency to slow this rate as the touching soil surface neared 13mm). Prior to the drop, soil around the edge of the brass cup was removed in order to minimise any energy transfer/dynamic process which negate against result accuracy and soil samples were taken from the drop soil as opposed to the soil on the mixing board. Distilled water, as opposed to tap water was also used to moisten the soil in order to prevent any minerals interfering with the soil plasticity.
Although the cone-penetromenter test is regarded as the more accurate of the two for determining the liquid limit of a soil, the lack of tested soils for this device lead to me using the water content from the Casangrande test as the liquid limit. Interpolating from the flow curve, 25 blows gives rise to a water content (liquid limit) of 46.0%.
Cone Penetration Limit (N.Z.S. 4402 Test 2.5)
During