How world you determine specific gravity? Explain.

Specific gravity is an important property by which the void ratio porosity degree of saturation particle size distribution etc are determined moreover it is useful in the study of quick sand condition and in estimation of zero air void line in the compaction theory a pycnometer or constant volume method has to be most reliable for the determination of specific gravity normally a 200 gram of dry mass of sample and a 500cc constant volume bottle are taken. The various steps to be followed for the determination of specific gravity G as follows:

• Find the weight of empty pycnometer
• The pycnometer is then filled with about 200 grams of dry sample and is weighted again.
• Water is then added in the pycnometer such that it is half full of water. The air in the soil sample is completely expelled by heating or suction. The water is added to its full capacity and pycnometer is weighted again.
• The pycnometer is then emptied and is filled with water only and its....

Specific gravity is an important property by which the void ratio porosity degree of saturation particle size distribution etc are determined moreover it is useful in the study of quick sand condition and in estimation of zero air void line in the compaction theory a pycnometer or constant volume method has to be most reliable for the determination of specific gravity normally a 200 gram of dry mass of sample and a 500cc constant volume bottle are taken. The various steps to be followed for the determination of specific gravity G as follows:

• Find the weight of empty pycnometer
• The pycnometer is then filled with about 200 grams of dry sample and is weighted again.
• Water is then added in the pycnometer such that it is half full of water. The air in the soil sample is completely expelled by heating or suction. The water is added to its full capacity and pycnometer is weighted again.
• The pycnometer is then emptied and is filled with water only and its weight is determined.

CALCULATIONS:

Let,

`W_s=`weight of dry soil

`W_1=`weight of pycnometer plus soil plus water

`W_2=`weight of pycnometer plus water

Now, by definition,

`Specific gravity of solid =(Weight Of Solid Of Volume 'V')/(Weight Of Same Volume Of Water At 4 degrees celsius)`

Or,`G=W_s/(gamma_0 *V_s)`

Again the specific gravity of water is,

`G_t=(gamma_w *V_w)/(gamma_0 * V_w)`

      `=gamma_w/gamma_0`

Thus,`G=(W_s*G_t)/(V_s*gamma_w)`

Again,we have,

`W_2=W_1-W_s+V_s*gamma_w`

 `V_s*gamma_w=W_2-W_1+W_s`

`(W_s*G_t)/G=W_2-W_1+W_s`

`G=(W_s*G_t)/(W_s-W_1+W_2)`

Generally,`G_t=1`.so,

`G=W_s/(W_s-W_1+W_2)`