This document summarizes a study on the effects of Ground Granulated Blast Furnace Slag (GGBS) on the geotechnical properties of black cotton soil. The study involved testing black cotton soil mixed with varying percentages of GGBS. Tests showed that adding GGBS increased the maximum dry density and decreased the optimum moisture content of the soil. It also significantly reduced swelling, and increased the unconfined compressive strength and California bearing ratio of the soil. Using 30% GGBS improved the engineering properties of the black cotton soil to meet specifications. Therefore, GGBS can effectively stabilize black cotton soil.

1. EFFECTS OF GGBS ON
GEOTECHNICAL PROPERTIES OF
BLACK COTTON SOIL
Under the guidance of
Shri. B.M. Gudadappanavar
Assistant Professor
DEPARTMENT OF CIVIL ENGINEERING
PRESENTED BY:
ABHIJEET KUMAR SINGH 2SD11CV001
AQUIB NASIR RAZI 2SD11CV009
DIBYAJYOTI SARMA 2SD11CV020
KAMLESH KUMAR 2SD11CV031
8th Semester B.E., Civil Academic Year: 2014-2015
1

2. CONTENTS
1. INTRODUCTION
2. LITERATURE REVIEW
3. OBJECTIVE OF THE STUDY
4. WHAT IS GGBS ?
5. METHODOLOGY
6. CONCLUSION
 REFERENCES
2

3.  Innovative methods of soil stabilization are in great demand all over the
world.
 Black cotton soil which is occupying nearly 23% of the area in India is a
problematic soil, available up to a depth of 3.7 meters on an average. The
black cotton soil has various problems like less stability, less shear strength
and large expansion & shrinkage in volume with changing seasons.
 These demerits obstruct construction like big infrastructure, road
pavements, etc. on this soil.
 Ground Granulated blast furnace slag(GGBS) have puzzolanic properties
and are being used in the construction industry along with cement or lime as
activators.
 Very few researchers have done some work in the stabilization of black
cotton soils using GGBS.
INTRODUCTION
3

4. LITERATURE REVIEW
Various researchers evaluated the potential of GGBS to stabilize soil.
 Gyanen Takhelmayum, Savitha, Krishna Gudi (March 2013) carried out a
series of test on black cotton soil with various proportions of GGBS . They
concluded that addition of GGBS to black cotton soil in various
percentages affects the compaction characteristic which is primarily due to
alteration of gradation of soil mixtures. The increase of the maximum dry
unit weight with the increase of the percentage of GGBS is mainly due to
the higher specific gravity of the fine GGBS compared with expansive soil
and the immediate formation of cemented products by hydration which
increases the density of soil.
 Laxmikant Yadu and Dr. R.K. Tripathi(2013) studied the effects of GGBS
in the engineering behavior of soft soil. The study and experimental results
indicated that the use of GGBS had significantly improved the physical and
strength properties of the soil and reduced swelling behavior of the soil.
4

5. LITERATURE REVIEW
o K V Manjunath ,Himanshu Shekhar ,Manish Kumar ,Prem Kumar and
Rakesh Kumar (2012) studied and carried out test to stabilize black
cotton soil using GGBS and concluded that the use of GGBS had
enhanced the engineering properties of the black cotton soil and had
increased the stability of the soil and Unconfined Compressive
Strength had increased after the percentage addition of GGBS to the
soil. Which came out to be an economical solution and partial
replacement of ordinary Portland cement.

6. OBJECTIVE OF THE STUDY
 To study the effects of Ground Granulated Blast Furnace
Slag(GGBS) on the Engineering performance of black cotton
soil and to check if it can be used as a soil stabilizer.
6

7. WHAT IS GGBS ?
 Ground granulated blast furnace slag (GGBS) is a by-product
from the blast-furnaces used to make iron. These operate at a
temperature of about 1,500 degrees centigrade and are fed with
a carefully controlled mixture of iron-ore, coke and limestone.
 The iron ore is reduced to iron and the remaining materials
form a slag that floats on top of the iron. This slag is
periodically tapped off as a
molten liquid and if it is to be
used for the manufacture of
GGBS it has to be rapidly
quenched in large volumes of
water.
7
GGBS

8. 8
o The quenching, optimizes the
cementitious properties and
produces granules similar to a
coarse sand. This ‘granulated’
slag is then dried and ground to a
fine powder.

9. BENEFITS OF USING GGBS
The major benefits of using GGBS are:
 better workability, making placing and compaction easier
 lower early-age temperature rise, reducing the risk of thermal
cracking in large pours
 high resistance to chloride ingress, reducing the risk of reinforcement
corrosion
9

10. METHODOLOGY
In this study, we have studied the variation in properties of black cotton
soil on addition of varying percentages of GGBS and the following tests
were carried out:-
 Test on Atterberg’s Limits
 Grain Size Distribution
 Free Swell Index
 Maximum Dry Density
 Unconfined Compressive Strength
 California Bearing Ratio
10

11. MATERIALS USED
 Black cotton soil : The soil used for this study were
collected from Y.S. Colony, Dharwad , Karnataka at a
depth of 0.5 m.
 GGBS : It was procured from PWD Dharwad and they
had brought it from Jindal Vijayanagar Steel Ltd in
Toranagallu, Bellary, Karnataka

12. PROPERTIES OF BLACK COTTON SOIL
SOIL CHARACTERISTICS DESCRIPTION
Maximum dry density 1.396 g/cc
Optimum moisture content 16%
Specific gravity 2.63
UCS 220 kPa
CBR (SOAKED) 2.36 %
Free swelling index 60%
Liquid limit 68%
Plastic limit 25%
Plasticity index 43%
12

13. BC SOIL +
FINE GGBS
LIQUID
LIMIT(WL)
PLASTIC
LIMIT(WP)
PLASTICITY
INDEX (IP)
100% + 0% 68% 25% 43%
90% + 10% 75% 42.85% 32.15%
80% + 20% 61% 42.85% 18.15%
70% + 30% 49% 42.85% 6.15%
ATTERBERG’S LIMITS (IS:2720(PART 5)-1985)
13
NOTE: As per MORTH specifications the plasticity index of soils to
be used for embankments, subgrades, earthen shoulders and
miscellaneous backfills should be less than 25.

14. PLASTICITY INDEX OF GGBS MIXES
0
5
10
15
20
25
30
35
40
45
50
0 10 20 30
PLASTICITYINDEX(%)
GGBS(%)
14

15. GRAIN SIZE DISTRIBUTION
(IS: 2720 (PART 4)-1985)
15
SL.NO IS SIEVE
PARTICLE
SIZE D(mm)
WEIGHT
RETAINED(
g)
PERCENT
RETAINED
CUMMULATIVE
%RETAINED
CUMMULATIVE %
FINER
1 100mm 100 0 0 0 100
2 63mm 63 0 0 0 100
3 20mm 20 0 0 0 100
4 10mm 10 0 0 0 100
5 4.75mm 4.75 6 0.6 0.6 99.4
6 2mm 2 18 1.8 2.4 97.6
7 1mm 1 12 1.2 3.6 96.4
8 600micron 0.6 0 0 3.6 96.4
9 425micron 0.425 11 1.1 4.7 95.3
10 300micron 0.3 8 0.8 5.5 94.5
11 212micron 0.212 7 0.7 6.2 93.8
12 150micron 0.15 9 0.9 7.1 92.9
13 75micron 0.075 14 1.4 8.5 91.5
14 PAN <0.075 915 91.5 100

16. GRAIN SIZE DISTRIBUTION GRAPH
16
91
92
93
94
95
96
97
98
99
100
101
0.01 0.1 1 10 100
PERCENTAGEFINER(N)
PARTICLE SIZE IN MM

17. GRAIN SIZE ANALYSIS
% OF GRAVEL 0.6
% OF SAND PARTICLES 7.9
% OF SILT and CLAY 91.5
SOIL CLASSIFICATION
INDIAN STANDARD SOIL CLASSIFICATION CH
17
NOTE: As per MORTH specifications any soil that classifies as OL, OH ,
or Pt are considered as unsuitable for the construction of embankments.

18. FREE SWELLING INDEX
(IS: 2720(PART 40)- 1977)
18
BC SOIL +
GGBS
FREE
SWELLING
INDEX(%)
100% + 0% 60
90% + 10% 40
80% + 20% 20
70% + 30% 10

19. MAX DRY DENSITY OF BC SOIL ON
ADDITION OF FINE GGBS
(IS: 2720(PART 8)- 1983)
1.2
1.3
1.4
1.5
1.6
1.7
1.8
10 12 14 16 18 20
MAXDRYDENSITY(g/cc)
OPTIMUM MOISTURE CONTENT (%)
BC SOIL
10% GGBS
20% GGBS
30% GGBS
19

20. BC SOIL + FINE
GGBS
O.M.C(%)
ρ (g/cc)
100% + 0% 16 1.396 (13.63 KN/m3)
90% + 10% 15 1.43 (14.03 KN/m3)
80% + 20% 14 1.46 (14.32 KN/m3)
70% + 30% 10 1.66 ( 16.28 KN/m3)
NOTE:
Density requirements of Embankments and sub-grade materials as per
MORTH specifications should not be less than 16 KN/m3
20

21. UNCONFINED COMPRESSIVE STRENGTH
(IS: 2720(PART 10)- 1991)
UNCONFINED COMPRESSIVE STRENGTH IN kPa
No of days of
curing
0 7 28
BC SOIL ONLY 220 220 220
BCS + 10% GGBS 151.2 222.8 247.9
BCS + 20% GGBS 191.6 434.2 450.8
BCS + 30% GGBS 214 1712.2 1882.2
21
NOTE: Unconfined Compressive strength has increased
up to 8 times that of ordinary Black Cotton Soil.

22. STRENGTH VARIATION ON ADDITION OF GGBS
0
200
400
600
800
1000
1200
1400
1600
1800
2000
0 7 28
UCCSTRENGTHINKPa
NO. OF DAYS OF CURING
0% GGBS
10% GGBS
20% GGBS
30% GGBS
22

23. CBR VALUES (IS:2720(PART 16)-1987)
GGBS CBR (%)
0% 2.36
10% 2.67
20% 4.72
30% 14.96
23

24. CBR VALUES
2.36 2.67
4.72
14.96
0
2
4
6
8
10
12
14
16
0 10 20 30
CBR(%)
PERCENTAGE OF GGBS
24

25. COST ANALYSIS
Pavement thickness 795 mm 475 mm
Semi dense bituminous concrete 25 mm 25 mm
Dense bituminous concrete 70 mm 50 mm
Granular base 250 mm 250 mm
Granular sub-base 450 mm 150 mm
Estimated cost Rs 62,35,706.2 Rs 53,49,281.2
Assumptions:
• N= 5 msa
• Width of subgrade=7.5m
• Carriage width =3.75m
• Road length = 1 km
WITHOUT USING
GGBS
USING GGBS (30%)
It is apparent that there is 14 % savings by using GGBS.
PAVEMENT COMPOSITION

26. CONCLUSION
 MDD increased while OMC decreased with addition
of GGBS to the soil.
 There is significant reduction in the swelling
behaviour of the soil.
 UCS has increased up to 8 times that of ordinary
Black Cotton Soil by adding 30% GGBS.
 CBR value has increased up to 7 times that of
ordinary Black Cotton Soil by adding 30% GGBS.
 The blended soil meets the requirements as per
MORTH specifications of subgrade.
 Hence GGBS can be used for the stabilization of
Black Cotton Soil as it has significantly improved
the geotechnical properties of Black Cotton Soil.
26

27. REFERENCES
[1]. GyanenTakhelmayum1, savitha.A.L2, Krishna Gudi GSS Institute of Technology,
VTU “Experimental Studies on Soil Stabilization Using Fine and Coarse GGBS”, ISSN
2250-2459, ISO 9001:2008 Certified Journal, Volume 3, Issue 3, March 2013
[2]. Laxmikant Yadu and Dr. R.K. Tripathi “Effects of Granulated Blast Furnace Slag in
the Engineering Behavior of Stabilized Soft Soil", Chemical, Civil and Mechanically
Engineering tracks of third Nirma University International Conference, Procedia
Engineering 51 (2013)125-131.
[3]. K.V. Manjunath, Himanshu Shekhar, Manish Kumar, Prem Kumar and Rakesh
Kumar “Stabilization of Black Cotton Soil Using Ground Granulated Blast Furnace
Slag”, Proceedings of International Conference on Advances in Architecture and Civil
Engineering (AARCV 2012), 21st - 23rd June 2012 387 Paper ID GET114, Vol. 1
[4].IS:2720 (PART-4)-1985, Methods of test for soils: Part 4 Grain size analysis
(Second Revisions). 27

28. REFERENCES
[5].IS:2720 (PART-5)-1985, Methods of test for soils: Part 5 Determination
of liquid limit and Plastic limit (Second revision).
[6].IS:27270 (PART-8)-1983, Methods of test for soils: Part 8
Determination of water content-dry density relation using heavy
compaction (Second Revision).
[7].IS:2720 (Part-10)-1973, Methods of test for soils: Part 10
Determination of Unconfined compressive strength (First Revision).
[8].IS:2720 (Part -16)-1979, Methods of test for soils: Part 16 Laboratory
determination of CBR. (First revision).
[9].IS:2720 (Part -40)-1977, Methods of test for soils: Part 40
Determination of free swelling index of soils.
28

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