1. Compaction According ASTM D 1557/02
Experiment # 3
Compaction
According ASTM D 1557/02
Soil Mechanics Lab CE 350
Compaction

2. Content Definition of Compaction Effective of compaction
Type of Compaction
Objective
Data and Calculation
Compaction Curves
Application
Soil Mechanics Lab CE 350
Compaction

3. What is compaction? + water =
A simple ground improvement technique, where the soil is densified through external compactive effort.
Compactive effort
+ water =
Soil Mechanics Lab CE 350
Compaction

4. Compaction Effect Solid Air Water Solid Loose soil Compacted soil
Soil Mechanics Lab CE 350
Compaction

5. Type of Test Standard Proctor Modified Proctor Weight of Hammer 5.5 Ib
Height of Hammer
1 ft
1.5 ft
Number of Blows 25
Number of Layers 3 5
Volume of Mold
1/30 ft3
(944 cm3)
Energy= (Weight of Hammer* Height of Hammer*Number of Blows*Number of Layers) Volume of Mold
Soil Mechanics Lab CE 350
Compaction

6. Objective Determine the maximum dry unit weight.
Determine the optimum water content.
Soil Mechanics Lab CE 350
Compaction

7. REQUIRED APPARATUS Compaction mold with plate and collar
Automatic Compactor Machine
Moisture tins.
Steel straight edge
Mixing pan.
Sample extruder.
Trimming knife
Drying oven
Sieve No. 4.
Balance, sensitive to  0.01 gm.
Soil Mechanics Lab CE 350
Compaction

8. REQUIRED MEASUREMENTS
Volume of compaction mold, Vm.
Moisture content of soil specimen, w.
Weight of mold and compacted soil specimen, Wms
Weight of clean empty mold, Wm.
Soil Mechanics Lab CE 350
Compaction

9. Dry Density Determination Water Content Determination
Dry unit weight (gm/cm3)
Mold No.
Weight of mold (gm)
Weight of mold + soil (gm)
Weight of soil
(gm)
Moist unit weight (gm/cm3)
Can
no.
Weight of can
Weight of can + soil
Weight of can + dry soil
Weight of water (gm)
Weight of dry soil (gm)
Water content (%)
Avg. water content 1 2 3 4
Soil Mechanics Lab CE 350
Compaction

10. Compaction Curve Direct Goal Increase shear strength Reduce settlement
Water content
Dry density (d)
Direct Goal
Increase shear strength
Reduce settlement
Reduce permeability
d, max
optimum water content
Soil Mechanics Lab CE 350
Compaction

11. Compaction Curve
What happens to the relative quantities of the three phases with addition of water?
soil
water
air
Water content
Dry density (d)
difficult to expel all air
lowest void ratio and highest dry density at optimum w
Soil Mechanics Lab CE 350
Compaction

12. Results w 12 14 16 18 d … Zero air void curve (S=100%) Modified
Water content
Dry density (d)
Zero air void curve (S=100%)
Modified w 12 14 16 18 d …
Standard
Soil Mechanics Lab CE 350
Compaction

13. Compaction Curves for Different Types of Soil
One peak
(Well Graded Sand)
Double peak
(Poorly Graded Sand)
Odd Shape
(Silt OR Poorly Graded Sand with Silt)
One & half peak
(Clay)
Soil Mechanics Lab CE 350
Compaction

14. Application Filling after excavation Filling behind retaining wall
Road base and sub base material
Soil Structure i.e. earth dam
Soil Mechanics Lab CE 350
Compaction