How to Determine Dry density by Core cutter method

Dry density by Core cutter method

Ref : IS 2720 (part XXIX)


Purpose : To find out the dry density of compacted soil in field.





Salient features of apparatus:


a) Dolly : Inner diameter : 100mm


Outer diameter : 115mm


Height : 25mm


b) Cutter : Inner diameter : 100mm


Outer diameter : 106mm


Height : 130mm


c) Rammer : Length : 900mm


Diameter : 140mm





Test Procedure:


1) Find the volume in cm3 and weight of the cutter in gms.


2) Expose about 30 cm2 of ground area and level it.


3) Put the dolly on the top of the core cutter and drive assembly into the soil with the help of the rammer until top of the dolly protrudes about 1.5cm above the surface. Detach the core cutter from the surrounding soil.


4) Trim flat end of the cutter.


5) Keep some representative specimen of soil for moisture content determination.


6) Find out dry density by using the following formula:


Dry density (γd) = γb /(1 + w)




Where


γb = Bulk density.


W = Moisture content.