1. International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308
(Print), ISSN 0976 – 6316(Online) Volume 4, Issue 3, May - June (2013), © IAEME
38
STABILIZATION OF MEDIUM PLASTIC CLAYS USING
INDUSTRIAL WASTES
Dr. K.V.Krishna Reddy
Professor & Principal, Chilkur Balaji Institute of Technology, Hyderabad-75, AP, India
ABSTRACT
In the present study, an attempt is made to determine the utility of industrial wastes in
stabilization of medium plastic clays (CI). Fly ash (FA) and waste tire rubber (WTR) have
been considered to investigate their potential in stabilizing the CI soils. Laboratory
experimentation is done to evaluate the optimum contents of fly ash and waste tire rubber
content to check the California Bearing Ratio strength (CBR), Differential Free Swell % and
Unconfined Compressive Strength (UCC) strength. The results indicated that the peak
strength values are obtained at 25% of flyash and 6% of waste tire rubber content by weight
of soil.
Key Words: Soil Stabilization, Medium Plastic Clays, Waste tire rubber, Fly ash
INTRODUCTION
With rapid industrialization and urbanization, extensive use of land has become
imminent and in most of the cases land is not readily useful because of low strength
characteristics. Clay soils are one among them which cover a large part of the country. In
absence of good areas that can take the load, it is imperative that the engineer has no
alternative but to look for methods of strengthening such areas. It is well-accepted fact that
industrialization and urbanization leads to production of a number of industrial wastes that
are of serious environmental concern. Two among them are flyash (FA) and waste tire rubber
(WTR). In this context the study is oriented to use them for stabilizing clay soils of medium
plasticity with a view to use them in pavements sector.
INTERNATIONAL JOURNAL OF CIVIL ENGINEERING AND
TECHNOLOGY (IJCIET)
ISSN 0976 – 6308 (Print)
ISSN 0976 – 6316(Online)
Volume 4, Issue 3, May - June (2013), pp. 38-44
© IAEME: www.iaeme.com/ijciet.asp
Journal Impact Factor (2013): 5.3277 (Calculated by GISI)
www.jifactor.com
IJCIET
© IAEME

2. International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308
(Print), ISSN 0976 – 6316(Online) Volume 4, Issue 3, May - June (2013), © IAEME
39
1. RESEARCH METHODOLOGY
Laboratory experimentation is done to determine the optimum additives content
for stabilizing the clay soil of medium plasticity (CI) with fly ash and waste tire rubber.
As the requirement for pavement sector aims at achieving not only a higher CBR value
but also volume stability. Differential Free Differential Free Swell % is also evaluated for
the stabilized soils and UCC Strength.
2.1 Flyash as additive
Clay of medium plasticity has been procured from Jadcherla, a place near to
Hyderabad. Flyash is available in abundant quantities from thermal power plants, free of
cost within a radius of 100km to avoid disposal problems. Flyash has been collected from
Ramagundam super thermal power plant for the study. Flyash is added at 15, 20, 25, 30
and 35% by weight of soil. IS heavy compaction test has been conducted on three
samples of CI soil and that of each modified mix to determine the maximum dry density
(MDD) and optimum moisture content (OMC). CBR test was conducted on three samples
of each mix at OMC, after curing for 7 days by covering with wet sand followed by 96
hours of soaking. Volume stability is investigated by evaluating the Atterberg limits and
Differential Free Swell % of the mix at optimum fly ash content.
2.2 Waste tire rubber as additive
Waste tire rubber obtained by grinding scrap pneumatic motor vehicle and truck
tires is procured locally. The same is added to CI soil at 2%,4%,6% and 8% by weight of
soil. IS heavy compaction test has been conducted on three samples of CI soil and that of
each modified mix to determine the maximum dry density (MDD) and optimum moisture
content (OMC). CBR test was conducted on three samples of each mix at OMC, after
curing for 7 days by covering with wet sand followed by 96 hours of soaking. Volume
stability is investigated by evaluating the Atterberg limits and Differential Free Swell %
of the mix at optimum WTR content.
3 DATA ANALYSIS
3.1 Basic Material Properties
The basic material properties used are depicted in the Tables 1 to 3. Table 1 gives
the properties of the CI soil, Table 2 represent the properties of waste tire rubber procured
and Table 3 depicts the physical and chemical properties of flyash.

3. International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308
(Print), ISSN 0976 – 6316(Online) Volume 4, Issue 3, May - June (2013), © IAEME
40
Table 1 Properties of CI soil
S. No. Property Value
1 Grain Size Distribution
Gravel (%)
Sand (%)
Silt size (%)
Clay size (%)
-
1.2
31.4
67.4
2 Atterberg Limits
Liquid Limit (%)
Plastic Limit (%)
Plasticity Index
48
25
23
3 Compaction properties
Optimum moisture content (%)
Maximum Dry Density (g/cc)
17.0
1.63
4 Soaked CBR (%) 2.86
5 Specific gravity 2.7
Table 2 Properties of waste tire rubber
Property Value
Parent Bus and Truck tire
Specific gravity 1.19
Particle size taken
Passing 1.18mm sieve
Retained on 0.6mm sieve
Table 3 Properties of Flyash
S. No. Property Pond ash
1 Grain Size Distribution
Gravel (%)
Sand (%)
Silt size (%)
Clay size (%)
-
54.6
43.6
1.8
2 Atterberg Limits NP
3 Specific gravity 2.04
4 Loss on ignition (%) 2.22
5 Chemical Composition (%)
SiO2
A12O3
Fe2O3
TiO2
K2O
CaO
Mn2O3
ZrO2
SrO
NiO
Nb2O5
V2O5
57.007
19.551
15.709
3.158
1.271
3.510
0.197
0.184
0.028
0.042
0.012
0.049

4. International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308
(Print), ISSN 0976 – 6316(Online) Volume 4, Issue 3, May - June (2013), © IAEME
41
3.2 Trials with flyash
As indicated in the methodology, flyash was added at the rate of 20, 25 and 30% by
weight of soil. It has been observed that there was a decrease in the optimum moisture
content from 17.05% to 16.50% with an increase in the flyash content from 0 to 30%. The
maximum dry density increased from 1.63g/cc to 1.68g/cc up to 25% flyash and then
decreased to 1.63g/cc as the flyash content increased to 30%.
The CBR value increased from 2.86 to 10.09 as the flyash content increased from 0 to
25% and then a decrease was observed with increase in the flyash beyond 25%. The
compaction characteristics and CBR values of the modified mix are depicted in Table 4. The
CBR curves for CI soil with flyash as admixture are depicted in Fig. 1.
Table 4 Properties of CI soil with flyash as admixture
S.
No
Property
Type of Mix
CI
CI +
20% FA
CI + 25% FA CI + 30% FA
1 Compaction
Properties
OMC (%)
MDD (g/cc)
17.0
1.63
16.95
1.658
16.80
1.675
16.50
1.630
2 Soaked CBR
(%)
2.86 4.97 10.09 7.08
0.00 100.00 200.00 300.00 400.00 500.00
Penetration (0.01mm)
0.00
50.00
100.00
150.00
200.00
250.00
Provingringreading(div)
1
2
3
4
SNO MIX CBR(%)
1 CI+0%FA 2.86
2 CI+20%FA 4.97
3 CI+25%FA 10.1
4 CI+30%FA 6.58
Fig1. Penetration Vs Proving Ring Reading for CI and FA Stabilized CI Soil
3.3 Trial with waste tire rubber
Waste tire rubber is added at 2%, 4%, 6% and 8% by weight of CI soil and the
compaction properties along with soaked CBR values are indicated in the table 5. It has been
observed that the maximum CBR strength occurred at an optimum rubber content of 6%. The
CBR curves for BC soil with waste tire rubber as admixture are depicted in Fig. 2

5. International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308
(Print), ISSN 0976 – 6316(Online) Volume 4, Issue 3, May - June (2013), © IAEME
42
Table 5 Properties of CI soil with Waste tire Rubber as admixture
S.
No
Property
Type of Mix
CI
CI +
2% WTR
CI + 4%
WTR
CI + 6%
WTR
CI + 8%
WTR
1 Compaction
Properties
OMC (%)
MDD (g/cc)
17.0
1.63
17.9
1.60
17.7
1.57
17.64
1.58
17.8
1.56
2 Soaked CBR
(%)
2.86 3.25 4.20 4.36 3.95
0.00 100.00 200.00 300.00 400.00 500.00
Penetration (0.01mm)
0.00
20.00
40.00
60.00
80.00
100.00
Provingringreading(DIV)
5
4
3
2
1
SNO MIX CBR(%)
1 CI+0%WTR 2.86
2 CI+2%WTR 3.25
3 CI+4%WTR 4.20
4 CI+6%WTR 4.36
5 CI+8%WTR 3.95
Fig2. Penetration Vs Proving Ring Reading for CI and WTR Stabilized CI Soil
4 RESULT
The Soaked CBR, Differential Free Swell % and the 7 day Unconfined Compressive
strength of the CI soil in comparison with the stabilized mixes are indicated in table 6.
Table 6 Differential Free swell and strength characteristics of stabilized mixes
S.
No
Property
Type of Mix
CI
CI +
25%FA
CI +
6%WTR
1 Soaked CBR (%) 2.65 10
2 Differential Free Swell (%) 22 11 17
3 UCC kN/m2
(7Day) 61 330 182

6. International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308
(Print), ISSN 0976 – 6316(Online) Volume 4, Issue 3, May - June (2013), © IAEME
43
5 ACKNOWLEDGEMENT
At the outset the author would thank the Head, CED, Vasavi college of Engineering,
SE R&B Department for their valuable guidance and encouragement during experimentation.
6. CONCLUSION
(a) 25% addition of fly ash to the medium plastic clay soils (CI) resulted in a CBR value
of 10% and a 7 Day UCC strength of 330 kN/Sqm.
(b) 6% addition of waste tire rubber content to CI soil resulted in a CBR value of 4.36%
and a 7 day UCC value of 80kN/Sqm.
(c) The differential free swell % evaluated for the optimal mixes indicated that the
stabilized mixes exhibited low expansiveness.
(d) Industrial wastes namely fly ash and waste tire rubber can be effectively used to
stabilize clay subgrades to achieve high strength values thus resulting in decreased
pavement thickness and low maintenance.
7. REFERENCES
1. Chaturvedi, A.C. (1977), “Expansive Soil in India with special reference to U.P.”, Proc.
of First National Symposium on Expansive Soils, HBTI- Kanpur, India, pp 2-1 to 2-5.
2. Chen, F.H (1988), “Foundations on Expansive Soils”, Elsevier Publishing Co.,
Amsterdam.
3. Chopra, S.K., Reshi, S.S., and Garg, S.K. (1964), “ Use of Fly Ash as a Pozzolana”,
Proc. Symposium on Pozzolan, their survey, Manufacture and Utilizat5ion, CRRI,
India, p.18.
4. Chu, S. C., and Kao, H. S. (1993), “A Study of Engineering Properties of a Clay
Modified by Flyash and Slag”, Flyash for Soil Improvement Geotechnical Special
Publication, Vol. 36, pp 89-99.
5. Chu, T.Y. (1955), “Soil Stabilisation with Lime Fly Ash mixture, Preliminary studies
with Silty and Clayey Soils”, HRB, No.108, p.102.
6. Cokca, E. (2001), “Use of Class C Fly Ashes for the Stabilisation of an Expansive
Soil”, Journal of Geotechnical and Geoenvironmental Engineering, Vol. 127, No.7, pp
568-573.
7. Collins, R. J., and Ciesielski, S. K. (1992), “Highway Construction use of wastes and
By-products” Utilization of Waste Materials in Civil Engineering Construction,
Published by ASCE, New York, pp.140-152
8. Eades, J.L., and Grim, R.E. (1960), “Reaction of Hydrated Lime with Pure Clay
Minerals in Soil Stabilisation”, HRB, No.262, pp.51-63.
9. Edil, T.B., Benson, C.H., Bin-Shafique, M.S., Tanyu, B.F., Kim, W.H., Senol. (2002),
“A Field Evaluation of Construction Alternatives for Roadways over Soft Subgrade”,
TRR-1786, TRB, pp 36-48.
10. Ferguson, G. (1993), “Use of self-cementing flyash as a soil stabilizing agent” Proc.
Geotechnical special publication, No. 36, ASCE, New York.
11. FHWA, (1995), “Flyash Facts for the Highway Engineers” FHNA – SA – 44 – 081,
December 1995, pp. 70.

7. International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308
(Print), ISSN 0976 – 6316(Online) Volume 4, Issue 3, May - June (2013), © IAEME
44
12. Ghosh, R.K., Chadda, L.R., Pant, C.S., and Sharma, R.K. (1973), “Stabilisation of
Alluvial Soils with both Lime and F1yash”, Journal of Indian Roads Congress, Vol. 35,
No.2, pp 481-511.
13. Gizienski, S.F., and Lee, L.J, (1965), “Comparison of Laboratory Swell Tests to Small
Field Tests”, Proc. 2nd
International Research and Engineering Conference on
Expansive Clay Soils, Texas.
14. Goecker, W.L. (1956), “Stabilisation of Fine Coarse Grained Soils with Lime and Fly
Ash Mixtures”, HRB, No.129, p.63.
15. Holtz, W.G and Gibbs, H.J (1956), “Engineering Properties of Expansive Clays”,
Transactions of ASCE, Vol. 121, pp 641-647.
16. Holtz, W.G., and Gibbs, H. J. (1959), “Expansive Clay Properties and Problems”,
Quarterly of Colorado Scholl of Mines, Vol. 54, No.4.
17. Hopkins, T.C., Beckham, T.L., Sun, L., Ni, B., and Butcher, B. (2002), “Long-Term
Benefits of Stabilizing Soil Subgrades” Rep. No. KTC-02-19/SPR-196-99-1F,
Kentucky Transportation Centre, University of Kentucky.
18. Little Dallas N. (1999), “Assessment of Insitu Structural Properties of Lime Stabilized
Clay Subgrades”, TRR-1546, pp. 13-31.
19. Ramana Murthy, V. (1998), “Study on Swell Pressure and the Method of Controlling
Swell of Expansive Soil”, Ph.D. Thesis, Kakatiya University, REC, Warangal.
20. Seda, J. H., Joon, L. C., & Carraro, J. A. (2007). Beneficial Use of Waste Tire Rubber
forSwelling Potential Mitigation in Expansive Soils. Geotechnical Special Publication
172.Denver, Colorado: American Society of Civil Engineers.
21. Youwai, S., & Bergado, D. (2003). Strength and Deformation Characteristics of
Shredded Rubber Tire-Sand Mixtures. Can. Geotech, 254-264.
22. Dr. K.V.Krishna Reddy, “Rutting Resistance of Filler Modified Bituminous Concrete
Surfaces”, International Journal of Civil Engineering & Technology (IJCIET), Volume
4, Issue 2, 2013, pp. 250 - 257, ISSN Print: 0976 – 6308, ISSN Online: 0976 – 6316.
23. Dr. K.V.Krishna Reddy and K.P.Reddy, “Maturity Period and Curing as Important
Quality Control Parameters for Lime Stabilized Clay Subgrades”, International Journal
of Civil Engineering & Technology (IJCIET), Volume 4, Issue 2, 2013, pp. 393 - 401,
ISSN Print: 0976 – 6308, ISSN Online: 0976 – 6316.
24. P.A. Ganeshwaran, Suji and S. Deepashri, “Evaluation of Mechanical Properties of Self
Compacting Concrete with Manufactured Sand and Fly Ash”, International Journal of
Civil Engineering & Technology (IJCIET), Volume 3, Issue 2, 2012, pp. 60 - 69, ISSN
Print: 0976 – 6308, ISSN Online: 0976 – 6316.