Determination Of Field Density Test Of Soil By Using Sand Replacement Method:

What Is The Sand Replacement Method?

(The Standard for this method is,  AASHTO - T - 191)

This Sand Replacement Method is used in the field to determine the soil compaction of required area that is compacted by some rolling vehicles, to measure the compaction by using Soil Replacement Method.

The other name of Soil Replacement Method is a Sand Cone Method. This whole process is called Field Density Test.

Sand Replacement Method

Apparatus Of Field Density Test:

• Sand Pouring Cylinder
• Calibrating Cone
• Moisture Container
• Metal Tray with a Central Hole
• Dry Sand (passing through 600 micron sieve)
• Balance
• Scraper Tool
• Brush
• Oven
• Spoon

Procedure Of Sand Replacement Test:

After calibrating the apparatus of field density test, take the initial weight of the sand with bottle (sand placed in the bottle) before going to site.

At the site keep the base plate down where test will operate, and digging out the soil from hole of base plate about 6 inches deep and diameter is same with base plate/ density plate, and collecting that excavated soil and weight it.

After this fill calibrated cylinder with sand and put on the base plate hole and then opened the valve/stopper.

When sand stops flowing and remove the cylinder from test hole of base plate.

Then weight the remaining sand with apparatus (in which sand is placed). Note all the values of sand and excavated soil.

After weighting the excavated soil and take some sample in weighted container for determination of moisture contents in the oven.

Now going to calibrate the sand replacement method first to operate the test,

Calibration Of Cone Method:

The standard code is, 

ASTM D – 1556

AASHTO - T – 181 - 191

First to take calibrating container and fill it with sand and weight it (e.g. 8000g) by using balance machine, and now this cone places on base plate, then opened the shutter of a cone and movement of sand will start, when sand stopped to move out the closed the shutter.

Remove the Cone from base plate and weight again of remaining sand (e.g. 6242g).

This sand should be clean and should take passed of sieve No. 16 and retained of sieves No. 30.

This method repeated three times same like first one that is mention above.

Calculation For Calibrated Cylinder:

Total Weight of sand with calibrating cylinder

After weight sand with calibrating cylinder

Weight of Cone

1.	Total Weight of Sand Calibration Cylinder	8000g	8000g	8000g
2.	Weight of sand with calibrating cylinder (after)	6242g	6245g	6247g
3.	Weight of Cone	1758g	1755g	1753g
	Average	1755.33

Read This: Moisture And Density Relationship

Calculation And Observation Of S.R.M:

Initial weight of sand + CAN                            8140gm

Residual weight (collected from site)                2500gm

Wt of sand Is Used                                         5640gm

Calibration Cylinder                                        1780gm

Unite Of Sand                                                1.415gm/c.c

Volume of Hole                                               2728c.c

Total sand in hole                                           3860gm

Weight of excavated soil + Bottle                     6280gm

Density        =     weight / Volume

Determination Of Moisture Contents:

Wt of container, w1                      =                     15.6gm

Wt of container + wet soil            =                     33gm

Wt of water                                 =                   1.4gm

Wt of container + dry soil             =                      31.6gm

Dry Density                                 =                    water / dry soil