1. Experiment # 2
Atterberg Limits

2. To obtain the Atterberg limits.
OBJECTIVES
To obtain the Atterberg limits.
To classify the soil.

3. Volume Vs. Water Content
Atterberg Limits
Volume Vs. Water Content
Shrinkage Limit (SL)
The Plastic Limit (PL)
The Liquid Limit (LL)

4. Sample Preparation Air-dried. Passes the No. 40 sieve.
Cured for a period of 24 hours.

5. Plastic Limit
Is the moisture content at which a thread of soil just begins to crack and crumble when rolled to a diameter of 3 mm (1/8 in).
PL= Average of moisture content.
Line No.
Trial No. 1 2
Tin number
Weight of tin (gm) 3
Weight of tin + Wet soil (gm) 4
Weight of tin + Dry soil (gm) 5
Weight of water, Ww (gm)
(line 3 – line 4) 6
Weight of dry soil, Ws (gm)
(line 4 – line 2) 7
Moisture content, w%
(line 5  line 6)*100

6. Liquid Limit
Is the moisture content at which a 2 mm wide groove in a soil will close for a distance 12 mm (1/2 in) when dropped 25 times, falling 1 cm each time at a rate of 2 drops per second in the standard liquid limit device.

7. LineNo.
Trial No. 1 2 3 4
Moisture tins number
Weight of tin (gm)
Weight of tin + Wet soil (gm)
Weight of tin + Dry soil (gm) 5
Weight of water, Ww (gm)
(line 3 – line 4) 6
Weight of dry soil, Ws (gm)
(line 4 – line 2) 7
Moisture content, w%
(line 5  line 6)*100 8
Number of blows, N

8. Plasticity Chart

9. How to differentiate between Silt & Clay?
Shake a spot of soil in your hand, if the surface become shine Silt.
Mix small portion of the sample with water, if the water become clear within 10 min Silt.
If the surface is smooth Caly.
How to differentiate between Organic & Inorganic Clay?