PRACTICAL 5
DETERMINATION OF MOISTURE-DENSITY RELATIONSHIP OF SOIL
(AASHTO compaction test AASHTO T 99-97) using 2.5 kg rammer (ASTM D 698-70)
Apparatus:
Proctor mould (dia. 4”, height 4.59”, volume 1/30 ft3 or 944cm3) with a detachable collar (dia. 4” & height 2”)
assembly and base plate
Rammer (weight 5.5 lbs & 12” drop)
Sieve # 04
Drying Oven
Weighing balance
Moisture Containers
Straight edge
PROCEDURE:
1. Take about 3 to 4kg of air-dried soil, pulverized it properly and pass through sieve#04 and add initial
moisture content 4 to 5%.
2. Record the weight of the mould without base plate & collar extension.
3. Record the weight of the mould without base plate & collar extension.
4. Place the soil in the mould in 3 layers of almost equal height, compact each layer using 25 undisturbed blows
of the proctor hammer.
5. Remove the collar and trim off the excess soil projecting above the mould
by using straight edge. Take the weight of mould with compacted soil in it.
6. Extrude the sample and break it to collect the sample for moisture content determination preferably from
middle of the specimen.
7. Place the molded soil into the pan, break it and mix it with other soil. Add more water to increase the
moisture content by 2%.
8. Repeat the procedure from step 4 to 7. The total number of determination should be at least four times.
Compute the data in tabulated form.
Calculations and Observations:
Moisture content determination:
Row-1 Weight of 44.96 49.98 55.45 59.36 56.30 80.97
can+wet soil
Row-2 Weight of 42.63 45.60 50.97 53.40 50.23 69.05
can+dry soil
Row-3 Weight of 2.33 4.12 5.02 5.96 6.07 10.92
water (row1-
row2)
Row-4 Weight of can 16.12 9.91 15.22 16.50 18.89 17.82
Row-5 Weight of dry 26.51 35.69 35.21 36.90 31.34 51.33
soil (row2-
row4)
Row-6 Moisture 8.78 12.27 14.25 16.15 19.23 20.90
content, m%
(row3/row5)
Dry density determination:
Test Data Test repeats
1 2 3 4 5 6
Row-1 Wt. of water
added each
trial
Row-2 Moisture
content, m%
Row-3 Wt. of
soil+mould
Row-4 Wt. of
mould
Row-5 Wt. of soil
(row3-row4)
Row-6 Wet density,
kg/m^3
(row5*1060)
Row-7 Dry density,
kg/m^3
Flow Curve:
Where,
X-axis shows the M.C. & y-axis shows the dry density of a soil sample
Precautions:
1. Provide uniform blows throughout each layer of soil.
2. Add moisture content carefully.
3. Use the hammer very carefully to avoid any injuries.
