Proctor test for soil is a compaction test that is carried out to determine the compaction properties of soil.
In actual, this test is used for determining the mass of dry soil per cubic metre when the soil is compacted over a range of moisture contents providing the maximum dry density at the optimum moisture content.
Proctor test includes establishing the relationship between the moisture content and dry density of soils compacted in a mould of a specific size with a 2.5kg rammer dropped from a height of 30cm.
1. Proctor mould having an internal diameter of 10.2cm and height of 11.6cm with a detachable collar and detachable base plate.
2. A mechanical rammer weighing 2.5kg.
3. Sample extruder
4. Sensitive balance
6. Graduated cylinder
7. Mixing tools such as the spoon, tray, trowel etc.
Procedures in Proctor Test for Soil:
The procedure for conducting the Proctor compaction test can be listed as follows:
1. Approximately 5kg of the oven-dried sample is taken in the given pan. Water is then poured in it such that the representative sample is dampened four to six percentage points below the optimum moisture content.
2. The Proctor mould is then weighed without the base plate and collar. After that, the collar and base plate are fixed.
3. Place the sample soil in three layers and each layer is compacted by 25 blows from the 2.5kg hammer.
4. The collar is then removed, compacted soil is trimmed with the straight edge and the mould is weighed.
5. The sample is then removed and slightly cut to obtain the sample for moisture content.
6. Then the results are analyzed as follows:
Wet density gm/cc= weight of compacted soil/944
Dry density= wet density/(1+w)
W= moisture content of the soil
The diameter of the mould =
Height of mould =
The volume of the mould, V=
The specific gravity of solids, G=
|Sl. No.||Observations and Calculations||Determination No.|
|1||Mass of empty mould with base plate|
|2||Mass of mould compacted soil and base plate|
|3||Mass of compacted soil M = (2) – (1)|
|5||Water content, w|
|8||Dry density at 100% saturation (theoretical)|
|9||Degree of saturation|