In Developing countries like India the effective use of supplementary materials in the field of construction is increasing to reduce the cost of construction and environmental effects. Soil stabilization is one of the methods of recycling the waste and to improve the properties of problematic soils and to make feasible on such soils. The waste material used in this study is an agro waste, namely Palm Oil Fuel Ash (POFA). The problematic soil used in this investigation is dispersive soil.

1. GEOTECHNICAL
CHARACTERIZATION OF
DISPERSIVE SOIL STABILIZED
WITH LIME AND POFA
Presented By:
Shoib B Wani
NIT Srinagar

2. INTRODUCTION
 In Developing countries like India the effective use of
supplementary materials in the field of construction is
increasing to reduce the cost of construction and
environmental effects.
 Soil stabilization is one of the methods of recycling the waste
and to improve the properties of problematic soils and to make
feasible on such soils.
 The waste material used in this study is an agro waste, namely
Palm Oil Fuel Ash (POFA)
 The problematic soil used in this investigation is Dispersive
soil.

3. Failures due to dispersion of soil
Failures at the Tumkur canal region

4. OBJECTIVE
• To improve the properties of dispersive soil by stabilization.
• To study the effect of various percentages of lime and palm oil fuel
ash alone and with lime – palm oil fuel ash combination on strength
properties (unconfined compressive strength ) with varying curing
period.

5. NEED FOR THE STUDY
• To promote safe uses of solid waste material such as Palm Oil
Fuel Ash in infrastructure development projects such as roads,
embankments, etc.
• To decrease the cost of stabilization by using POFA in lime
stabilization.

6. MATERIALS USED
Materials used:
• Soil sample
• Lime
• Palm Oil Fuel Ash
Tests performed on soil sample:
• Specific gravity test
• Grain size analysis
• Atterberg's limits
 Liquid limit
 Plastic limit
 Shrinkage limit
• Standard Proctor test
• Unconfined Compressive Strength (UCC)
• Double Hydrometer test.

7. SOIL PROPERTIES
Sl.No Parameters Symbol Value
1 Grain size distribution
Sand (s) 61.5
Slit(M) (%) 25.5
Clay(C) (%) 13
2 Liquid limit % Wl 41
3 Plastic limit% Wp 23.80
4 Plasticity Index% Ip 17.20
5 Shrinkage Limit % Ws 22
6 Specific Gravity G 2.63
7 Optimum Moisture Content OMC 14
8 Maximum Dry Density ϒd max 1.78g/cc
9 Unconfined Compressive Strength qu 1.71 kg/cm2
10 Percentage dispersion 42.10%
11 Soil classification Silty Sand (SM)
Properties of untreated soil

8. Soil properties
0
10
20
30
40
50
60
1 5 25
Water
content
(%)
Number of blows
Wl =41
Grain size analysis of untreated soil Liquid limit graph for untreated soil
Standard Proctor graph for untreated
soil
Γd max =1.78
OMC=14
0
10
20
30
40
50
60
70
80
90
100
0.001 0.01 0.1 1 10
Percentage
finer
(%)
Particle size(mm)
1.64
1.66
1.68
1.7
1.72
1.74
1.76
1.78
1.8
0 5 10 15 20 25
Dry
density(g/cc)
Water content (%)
Stress - strain characteristics for
untreated soil
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
0 0.010.020.030.040.050.060.070.080.09
Stress
(kg/cm
2
)
Strain

9. Soil properties
0
10
20
30
40
50
60
70
80
90
100
0.001 0.01 0.1
Percentagefiner
(%)
Particle size (mm)
with out dispersing agent
with dispersing agent
Double hydrometer curve for untreated soil

10. SOIL CLASSIFICATION
Percent dispersion = % passing 5μm (without dispersant agent) / % passing 5μm
(Standard) * 100
= 8/19 *100
= 42.10 %
The soil is classified as “ Intermediate dispersive”
Authors Percent dispersion (%) Dispersion property
ASTM D - 4221 Near 100 Completely dispersive
Near 0 Soil no dispersive
Decker et Dunnigan
(1977)
<35 No dispersivity problem
35 – 50 Probable dispersivity
>50 Problem of dispersivity
Knodel (1991) <30 No dispersive
30 – 50 Intermediate dispersive
>50 Dispersive

11. RESULTS AND DISCUSSION
Unconfined compressive strength
• The test samples were prepared by varying lime content
(2, 3, 4, 5%), POFA content (8, 10, 12, 14%) and lime –
POFA proportions with the respective MDD and OMC
obtain from standard proctor test.
• The specimens were cured for 1, 3, 7, 14 and 28 days.

12. Experimental results
Curing period = 1, 3, 7, 14 and 28 days
3% Lime
Stress-Strain characteristics of treaded soil with 3% Lime for varying
curing periods
0
2
4
6
8
10
12
14
16
0 0.5 1 1.5 2 2.5 3
Stress
(kg/cm
2
)
Strain
1 Day 3 Days 7 Days 14 Days 28 Days

13. Experimental results
Curing period = 1, 3, 7, 14 and 28 days
8% POFA
Stress-Strain characteristics of treaded soil with 8% POFA for varying
curing periods
0
1
2
3
4
5
6
7
8
0 0.5 1 1.5 2 2.5 3 3.5 4
Stress
(kg/cm
2
)
Strain
1 Day 3 Days 7 Days 14 Days 28 Days

14. Experimental results
Curing period = 1, 3, 7, 14 and 28 days
3% Lime & 12% POFA
Stress-Strain characteristics of treaded soil with 3% lime & 12% POFA for
varying curing periods
0
5
10
15
20
0 0.5 1 1.5 2 2.5 3 3.5 4
Stress
(kg/cm
2
)
Strain
1 Day 3 Days 7 Days 14 Days 28 Days

15. Experimental results
% of Admixtures
Unconfined compressive strength
Curing Period in days
Lime POFA 1 Day 3 Days 7 days 14 days 28 Days
2
0
2.91 3.8 5 8.2 11
3 3.35 4.8 5.35 10.3 13
4 4.35 5.15 5.5 10.4 13.4
5 4.45 5.4 5.9 10.45 13.45
0
8 2.52 2.65 2.75 3.9 5.1
10 2.2 2.28 2.5 3.45 4.39
12 1.83 1.92 2.44 2.72 3.25
14 1.61 1.72 2.17 2.6 2.9
3
8 2.25 3.72 6.4 9.9 15.1
10 2.4 4 7 12 16
12 2.65 4.2 7.2 12.25 17.3
14 2.6 3.11 6.8 8.6 12.9
Unconfined compressive strength with varying curing period of treated soil

16. Experimental results
% of Admixtures
% increase in Unconfined compressive strength
Curing Period in days
Lime POFA 1 3 7 14 28
2 0 70.18 122.22 192.40 379.53 543.27
3 95.91 180.70 212.87 502.34 660.23
4 154.39 201.17 221.64 508.19 683.63
5 160.23 215.79 245.03 511.11 686.55
0 8 47.37 54.97 60.82 128.07 198.25
10 28.65 33.33 46.20 101.75 156.73
12 7.02 12.28 42.69 59.06 90.06
14 -5.85 0.58 26.90 52.05 69.59
3 8 31.58 117.54 274.27 478.95 783.04
10 40.35 133.92 309.36 601.75 835.67
12 54.97 145.61 321.05 616.37 911.70
14 52.05 81.87 297.66 402.92 654.39
Percentage increase in unconfined compressive strength of treated soil

17. Unconfined compressive strength variation
0
2
4
6
8
10
12
14
16
18
0 1 2 3 4 5 6
Unconfined
compressive
strength(kg/cm
2
)
Lime (%)
1 Day curing 3 Days Curing
7 Days Curing 14 Days Curing
0
1
2
3
4
5
6
7
8
6 8 10 12 14
Unconfined
Compressive
Strength
(kg/cm
2
)
POFA (%)
1 Day curing 3 Days Curing
7 Days Curing 14 Days Curing
Unconfined compressive strength
of dispersive soil treated with
Lime
Unconfined compressive strength of
dispersive soil treated with palm oil
fuel ash (POFA)

18. Unconfined compressive strength variation
0
5
10
15
20
6 8 10 12 14 16
Unconfined
compressive
strength
(kg/cm
2
)
POFA (%)
1 Day Curing 3 Days Curing 7 Days Curing
14 Days Curing 28 Days Curing
Unconfined compressive strength of dispersive soil treated with 3% Lime and
variation of palm oil fuel ash (POFA) percent

19. Effect of curing period on Unconfined
compressive strength
0
2
4
6
8
10
12
14
16
18
0 5 10 15 20 25 30
Unconfined
compressive
strength
(kg/cm
2
)
Curing period in days
2% Lime 3% Lime
4% Lime 5% Lime
0
1
2
3
4
5
6
7
8
0 10 20 30
Unconfined
compressive
strength
(kg/cm
2
)
Curing period in days
8% POFA 10% POFA
12% POFA 14% POFA
Effect of curing period on unconfined
compressive strength of dispersive
soil treated with Lime.
Effect of curing period on
unconfined compressive strength of
dispersive soil treated with Palm oil
fuel ash (POFA)

20. Effect of curing period on Unconfined
compressive strength
0
5
10
15
20
0 10 20 30
Unconfined
compressive
strength
(kg/cm
2
)
Curing period in days
3% Lime & 8% POFA 3% Lime & 10% POFA
3% Lime & 12% POFA 3% Lime & 14% POFA
Effect of curing period on unconfined compressive strength of dispersive soil
treated with 3% Lime and varying Palm oil fuel ash (POFA) percent

21. CONCLUSION
• The agro waste (Palm oil fuel ash) used in in this study is giving
good results and improving the properties of dispersive soil.
• Using 3% lime alone the unconfined compressive strength of the
soil is increased by 7.6 times for a curing period of 28 days.
• Using 8% POFA as soil stabilizer increases the unconfined
compressive strength by 2.98 times for a curing period of 28 days.
• Using 3% lime and 12% POFA the unconfined compressive
strength is increased by 10.11 times for a curing period of 28 days.
• Use of palm oil fuel ash as stabilizer decreases the cost of
stabilization and is effective for long term stabilization of soil.

22. REFERENCES
• ASTM D 4221 (1999) “Standard Test Method for Dispersive Characteristics
of Clay Soil by Double Hydrometer” Annual Book of ASTM Standards, vol.
04.08.
• Decker, R. S. and Dunnigan, L. P. (1977) “Development and Use of the SCS
Dispersion, Test” Dispersive Clays, Related Piping, and Erosion in
Geotechnical Engineering Projects, ASTM Special Technical Publication No.
623, American Society for Testing and Materials, pp 94-109.
• Knodel, P. C. (1991) “Characteristics and problems of dispersive clay soils”
United States Department of the Interior, Colorado.
• Mahabir D. and Gupta S.L., (2011), “Problems in characterization and
Identification of dispersive soils - a case study”, International J. of Earth
Science And Engineering, ISSN 0974-5904, Vol.4, No.6 Spl, pp.143-146.
• Oyeleke R.B., Yusof M.B.B.M., Razman M.B.S. and Ahmed k. (2011), “
Compaction parameters of kaolin clay modified with palm oil fuel ash as
landfill liner” , IEEE First Conference on Clean Energy and Technology CET,
pp 199-204

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24. Thank you