Core cutter method is used for determining the dry density of the soil(field compaction).
A cylindrical core cutter is a seamless steel tube. For determination of the dry density of the soil, the cutter is pressed into the soil mass so that it is filled with the soil. The cutter filled with the soil is lifted up. The mass of the soil in the cutter is determined. The dry density is obtained as
Where M= mass of the wet soil in the cutter
V= internal volume of the cutter
w= water content.
1- Cylindrical core cutter, 100mm internal diameter and 130mm long
2- Steel rammer, mass 9kg, overall length with the foot and staff about 900mm.
3- Steel Dolley, 25mm high and 100mm internal diameter
4- Weighing balance, accuracy 1g.
5- Palette knife
6- Straight edge, steel rule etc
1- Determine the internal diameter and height of the core cutter to the nearest 0.25mm
2- Determine the mass (M1) of the cutter to the nearest gram.
3- Expose a small area of the soil to be tested. Level the surface, about 300mm square in area.
4- Place the Dolley over the top of the core cutter and press the core cutter into the soil mass using the rammer. Stop the pressing when about 15mm of the Dolley protrudes above the soil surface.
5- Remove the soil surrounding the core cutter, and take out the core cutter. Soil would project from the lower end of the cutter.
6- Remove the Dolley. Trim the tip and bottom surface of the core cutter carefully using a straight edge.
7- Weigh the core cutter filled with the soil to the nearest gram (M2).
8- Remove the core of the soil from the cutter. Take a representative sample for the water content determination.
9- Determine the water content.
Observation and calculations
|Sl. No.||Observations and Calculations||Determination No.|
|1||Core cutter No.|
|4||Mass of empty core cutter (M1)|
|5||Mass of core cutter with soils (M2)|
|6||M=M2 – M1|
|7||The volume of cutter V|
|9||Dry density using formula|
Results of Core Cutter Method
Dry density of the soil= ________g/ml.