COMPACTION

Question 1

what is the objective of this lab test?

Answer 1

To determine the optimal water content at which the soil sample can reach its maximum dry density.

Question 2

List all the equipments.

Answer 2

1. 4 inch mold having one thirtieth of a cubic foot
2. collar
3. Standard proctor compaction hammer (5 and a half pounds & dropping 12 inches)
4. 2 moisture content cans
5. A steel straightedge
6. A large mixing pan
7. A graduated cylinder (holding up to 250 ml)
8. A spray bottle
9. A metal spoon
10. knife
11. digital balance
12. Oven

Question 3

Explain the procedure.

Answer 3

1. A representative soil is obtained. The soil mass and empty proctor mold is weighed without the collar. The soil is sieved.
2. The two moisture content cans are weighed and the dimension are measured to determine the volume.
3. The soil was placed in the mixer and water was added gradually to reach the desired moisture content
4. Lubricant was applied to the collar
5. The soil were removed from the mixer and placed it in the mold in 3 or 5 layers.
6. For each layer, the compaction were initiated with 25 blows per layer. The drops are applied manually or mechanically at a steady rate.
7. The soil mass filled the mold and extend into the collar but not more than 1 cm.
8. The collar were removed carefully and the soil that extends above the mold with a sharpened straight edge were trimmed.
9. The mold and the containing soil (W) were weighted.
10. The soil was extruded from the mold using a metallic extruder, making sure that the extruder and the mold are in-line.
11. The water content from the top, middle and bottom of the sample were measured.
12. The soil placed again in the mixer and water was added to achieve higher water content.

Question 4

How to analyze the data?

Answer 4

by plotting the graph of moisture content vs dry unit weight. from this, can determine optimum water content and maximum dry unit weight.