Efficient Way to Improve Subgrade Property of Pavement by Chemical Stabilization

Rajshekhar G Rathod . Int. Journal of Engineering Research and Application www.ijera.com
ISSN : 2248-9622, Vol. 7, Issue 1, ( Part -2) January 2017, pp.83-96
www.ijera.com 83 | P a g e
Efficient Way to Improve Subgrade Property of Pavement by
Chemical Stabilization
Rajshekhar G Rathod
Assistant Professor Maharashtra Institute of technology College of Engineering, Kothrud, Pune, India
ABSTRACT
There are numerous soil stabilization techniques for improving the strength of the in-situ soil especially in road
construction, and one of the techniques is using chemical additive. Chemical improvement is a time saving
method that enables subgrade or sub-base layer and otherwise unsatisfactory materials in-situ to obtain higher
density and strength, obviating the need for costly excavation and replacement with borrow material. This paper
presents some results of the preliminary stages of research program carried out to explicate the mechanism and
behavior between the liquid chemical and the engineering properties of three natural residual soils at laboratory
scale. Liquid-formed chemical was selected in this research due to scarcity of such findings instead of the
prevalent solid chemical additive such as lime, cement or fly ash. The focus on this research is on the
improvement of engineering properties of two natural residual soils and mixed with different proportions of
liquid chemical. Series of laboratory test on engineering properties, such as Modified Proctor Test, Consistency
limits, moisture-density relationship (compaction) and California Bearing Ratio was undertaken to evaluate the
effectiveness and performances of this chemical as soil stabilizing agent.
I. INTRODUCTION
1.1 General
Over the past few decades several factors
have led to an increase in the number of people
migrating to large cities. Consequently these large
cities are getting over populated and quite
expectedly necessity of business, residential
construction has increased the civil engineering
projects located in areas with unsuitable soil is one
of the most common problems in many parts of the
world. The unsuitable soil (Black cotton Soil) can
be stabilized by performing soil stabilization. In
India black soil is the most problematic soil when it
comes to construction. In rainy season black cotton
soil swells and become sticky. Whereas in
summers the moisture present in the soil evaporates
and soil shrinks resulting in the crack of
approximate 10 to 15 cm wide and up to 1 meter
deep. The percentage covered by black cotton soil
in geotechnical areas of India is 16.6%, which says
huge amount of soil in India needs stabilization.
Mechanical, chemical, electrical, thermal and other
methods are in practice to improve the engineering
properties of soil.
In developing countries like India the
biggest handicap to provide a complete network of
road system is the limited finances available to
build road by the conventional methods. Therefore
there is a need for low cost road construction to
meet the growing needs of the road traffic. The
construction cost can be considerably decreased by
selecting local materials including local soils for
the construction of the lower layers of the
pavement such as the embankment and sub-base
course. If the stability of the local soil is not
adequate for supporting wheel loads, the properties
are improved by soil stabilization techniques. Thus
the principle of soil stabilized road construction
involves the effective utilization of local soils and
other suitable stabilizing agents.
1.2 Project Undertaken
The work presented in this paper is a
contribution to the application of chemical and
conventional stabilization techniques, by adding
terrasil and river sand for two different soil i.e. red
soil and black cotton soil. Initially, the chemical,
physical and geotechnical properties of the
untreated soils were determined. These tests were
complemented by direct measurements of the
properties of both the soil i.e. consistency limits,
heavy compaction, specific gravity and California
bearing ratio. Secondly, the study examined the
effects of different types of stabilization on the
physical properties of both the soils.
II. MATERIAL AND
METHODOLOGY
2.1 Introduction
Soil has various meaning, depending upon the
general professional field in which it is being
considered in general soil mean the top layer of the
earth surface in which plants can grow consisting
of rocks and minerals particles mixed with decayed
organic matter and having the capability of
RESEARCH ARTICLE OPEN ACCESS

retaining water. And thus stabilizing soil gives
better bearing capacity.
2.2 Types of Soil
a. Black cotton soil
In this study, the soil under scrutiny was
gathered from the vicinity of Flora Institute Of
Technology, Khopi, Pune. At first, so as to
distinguish the wide soil sorts in the field with no
research facility testing, a visual characterization is
done, which demonstrates that soil under scrutiny
is brown in shading, further examination is
completed with water to make a paste and rubbed
in middle of fingers leaves a stain which is not
watched for residues. When it is wet it doesn't get
to be dry soon. In like way, display swelling and
shrinkage and are described by a typical shrinkage
pattern. The soil has an expansive surface zone
because of level and lengthened molecule shapes
that stick together when wet, avoiding typical
waste procedures. When it is wet it doesn't get to be
dry soon. In like way, when completely dry, it is
not soon wetted and shrinks causing breaks.
b. Red soil
Red soil is derived from weathering of
ancient metamorphic rock of the Deccan plateau.
Red soil is any of a group of soil that grow in a
humid temperature, moist climate under deciduous
and mix forests and that have raw mineral. Thin
organic layers overlying a yellowish brown
leached deposit resting on an alluvial. Their colour
is mostly ferric oxides occurring a slight coatings
on the soil particle through the iron oxide arise as
hematite as hydrous ferric oxide, the colour is red
and when it happen in the hydrate system as
limonite the soil become to be yellow colour.
Generally the surface soils are red while the
horizon under gets yellowish colour.
c. River sand
Sand is natural occurring granular material
composed of finely divided rock & mineral
particles. It is defined by size, being finer than
gravel & coarser than silt. Sand can also refer
toward textural class of soil or soil type that is a
soil containing more than 85% sand size particles
(by mass).
The composition of sand varies, depending on the
local rock sources and conditions, but the most
common constituent of sand in inland continental
settings and non-tropical coastal settings
is silica (silicon dioxide, or SiO2), usually in the
form of quartz. The second most common type of
sand is calcium carbonate, for example aragonite,
which has mostly been created, over the past half
billion years, by various forms of life,
like coral and shellfish. It is, for example, the
primary form of sand apparent in areas where reefs
have dominated the ecosystem for millions of years
like the Caribbean.
2.3 Tests On Soil
Test to know the engineering properties of soil can
be carried out on site as well laboratory. On-site
test are as follows:
1.Standard Penetration Test.
2.Cone Penetration Test, etc.
laboratory test are as follows:
1. Atterberg Limits Test.
2. California Bearing Ratio.
3. Direct Shear Test.
4. Expansion Index Test.
5. Soil Compaction Test.
6. Unconfined Compression Test etc.
2.4 Types of stabilization
1. Mechanical stabilization
2. Lime stabilization.
3. Cement stabilization.
4. Lime-fly ash stabilization.
5. Using Bitumen.
6. Other chemicals like Stabling, RBI-81, Soil fix and
Zydex etc.
2.5 Type of Chemical
a. Terrasil
Terrasil is nanotechnology based 100
percent organo silane, water dissolvable, bright and
warmth steady, receptive soil modifier to
waterproof soil subgrade. The Characteristics of
Terrasil is such that it wipes out narrow ascent and
water entrance from top, decreases water
penetrability of soil bases (10-5 cm/s to 10-7 cm/s)
while keeping up 100% vapor porousness,
diminishes expansively and free swell, keeps up
dry CBR under wet conditions, holds quality of
road bases and expands imperviousness to
deformation by keeping up frictional values
between residue and controls disintegration of soils
. TERRASIL is anything but difficult to utilize and
safe to handle item that renders treated soils very
water repellant. Terrasil conveys demonstrated
results with a wide range of soils and doesn't
modify their appearance. Terrasil is a think that
blends with water. Once connected, it attempts to
bond with the soil's silica and oxygen atoms. This
implanted synthetic response makes the treated soil
98% water safe. The holding procedure starts
inside of 3 hours of the beginning application till
the procedure is finished (72 hrs.), Terrasil turns
into a changeless piece of every soil particle and
won't separate or filter into groundwater .

Table 1 Chemical composition of terrasil.
Chemical Compound Value in Range(%)
Hydroxyalkyl-alkoxy-alkylsilyl 65-70%
Benzyl Alcohol 25-27%
Ethylene Glycol 3-5%
2.6 Engineering Property of Soil
Table 2 General properties of soil.
Properties Black cotton soil Red soil
Liquid limit 75% 41%
Plastic limits 35% 20.15%
Plasticity index 40 19.85%
Free swelling index 17.50% 0
Specific gravity 2.51 2.64
Dry density gm/cc 1.34 1.775
Moisture content 25.54% 15%
III. LABORATORY WORK
3.1 General
Performed various laboratory test on soil
i.e Red and Black cotton soil to find out their basic
properties such as liquid limit, plastic limit, specific
gravity, modified proctor & CBR tests.And soil
stabilization by using conventional stabilisation for
both red and black cotton soil by using natural river
sand(10%) & chemical stabilisation for both red &
black cotton soil by using Terrasil(0.041%) from
Zydex Industries.
3.2 Conventional Method Engineering
Properties
In conventional method 10% of natural
river sand is used as an additives to the soil i.e.
both red and black cotton soil by weight of soil. All
the test such as liquid limit, plastic limit, specific
gravity, modified proctor & C.B.R test were
performed on respective soils.
Red soil
Liquid limit
Table 3 LL of Red soil with 10% sand.
No I II III
No. Of blows 24 25.5 28
Container no 1 2 3
Mass of container + wet soil(g) 25 33 27
Mass of container + dry soil(g) 22.5 28.5 24
Mass of water (g) 2.5 4.5 3
Mass of container (g)(W1) 16 16 16
Mass of oven dry soil (g)(W2) 6.5 12.5 8
Water content (%) 38.46 36 37.5
Fig. 1 Flow curve for Red Soil with 10% sand.

Liquid Limit:- 38.5
Plastic limit
Table 4 PL of Red soil with 10% sand.
No I II III
CONTAINER NO 1 2 3
Wt of container 16.5 16.5 16.5
Wt of cont+ wet of soil 23.5 22 22.6
Wt of cont. + dry soil 21 20.5 20
Wt of water 2.5 1.5 2.6
Wt of dry soil 7 6 6.5
Water content 35 25 40
Plastic Limit:-33.33
Specific gravity [IS: 2720 (Part-III/SEC-I)]
Table 5 Specific Gravity Test for Red soil with 10% sand.
Determination I II III
Density bottle no 1 (250gm) 2 (350 gm) 3 (300 gm)
Mass of density bottle 681 681 681
Mass of density bottle + dry soil 932 1032 982
Mass of density bottle + soil + water 1653 1684 1668
Mass of bottle +water 1506 1506 1506
Specific gravity 2.41 2.02 2
Average Specific Gravity=2.14
Modified proctor test (Heavy Compaction)
Table 6 Proctor Test for Red soil with 10% sand.
Determination no I II III IV V
Wt of mould + compacted soil 5136 9096 10560 10120 9560
Wt of mould 5546 5546 5546 5546 5546
Volume of mould 2250 2250 2250 2250 2250
Wt of compacted soil 2567 3550 5014 4574 4014
bulk density 1.4 1.57 1.80 2.032 1.784
Dry density 1.29 1.42 1.56 1.722 1.48
Percentage of water use 6 10 15 18 20
Fig. 2 Compaction Curve for Red soil with 10% sand.

OMC: - 15% and MDD:- 1.7125 g/cm3
CBR
Table 7 Standard load used in C.B.R test.
Penetration Unit std. Load (kgf/cm2) Total std. Load (kgf)
2.5mm 70 1370
5mm 105 2055
7.5mm 134 2630
10mm 162 3180
12.5mm 183 3600
Table 8 C.B.R test of red soil with 10% sand.
Soil type Penetration CBR
Native 10% sand
Red soil @ 2.5 mm 6.5 8.37
@ 5.0 mm 7.99 9.47
Fig. 3 Load Penetration Curve for C.B.R test of Red soil with 10% Sand
Black cotton soil
Liquid limit
Table 9 LL B.C soil with 10% sand.
N0 I II III
No. Of blows 21 26 31
Container no 1 2 3
Mass of container + wet soil(g) 26 27.5 27
Mass of container + dry soil(g) 22.5 23.5 23
Mass of water (g) 3.5 4 4
Mass of container (g)(W1) 16.5 16.5 16.5
Mass of oven dry soil (g)(W2) 6 6 6.5
Water content (%) 58.3 61.63 66.66

Fig. 4 Flow curve for B.C soil with 10% sand.
Liquid Limit:-60.9
Plastic limit
Table 10 PL for B.C soil with 10% sand.
NO I II III
CONTAINER NO 1 2 3
Wt of cont+ wet of soil 24.5 23.5 23
Wt of cont. + dry soil 23 22 21.5
Wt of water 1.5 1.5 1.5
Water content 18.75 21.14 20
Plastic Limit:- 19.96
Specific gravity [IS: 2720 (Part-III/SEC-I)]
Table 11 Specific gravity test for B.C soil with 10% sand.
Determination I II III
Density bottle no 1 2 3
Mass of density bottle 681 681 681
Mass of density bottle + dry soil 932 1033 980
Mass of density bottle + soil + water 1640 1714 1677
Mass of bottle +water 1506 1506 1506
Specific gravity 2.14 2.44 2.33
Average Specific Gravity:-2.30
Modified proctor test(Heavy Compaction)
Table 12 Proctor Test for B.C soil with 10% of Sand.
Determination no I II III IV
Wt of mould + compacted soil 8966 9331 9790 9565
Wt of mould 5546 5546 5546 5546
Volume of mould 2250 2250 2250 2250
Wt of compacted soil 3420 3785 4244 5546
bulk density 1.52 1.68 1.88 1.78
Dry density 1.43 1.55 1.70 1.56
Percentage of water use 6 8 10 13

Fig. 5 Compaction Curve for B.C soil with 10% Sand.
OMC:- 10.125% and MDD:- 1.7 g/cm3
CBR
Table13 Standard load used in C.B.R test.
Penetration Unit std. Load (kgf/cm2) Total std. Load (kgf)
2.5mm 70 1370
5mm 105 2055
7.5mm 134 2630
10mm 162 3180
12.5mm 183 3600
Table 14 C.B.R Test for B.C Soil with 10% sand.
Soil type Penetration CBR
Native 10% Sand
Black cotton soil @ 2.5 mm 1.64 2.05
@ 5.0 mm 1.42 1.8
Fig. 6 Load Penetration Curve for C.B.R Test of B.C soil with 10% sand.
4.3 Chemical Method Engineering Properties
In chemical method 0.041% of Terrasil is used as
an additive to the red & black cotton soil by weight
of soil. All the test such as liquid limit, plastic
limit, specific gravity, modified proctor & C.B.R
test were performed on respective soils.

Red soil
Liquid limit
Table 15 LL Red soil With 0.041% Terrasil.
N0 I II III
Container no 1 2 3
Mass of container + dry soil(g) 25 26.5 29
Mass of water (g) 1 1.5 1
Mass of oven dry soil (g)(W2) 8.5 10 12.5
Water content (%) 11.76 15 8
Fig. 7 Flow curve for Red Soil with 0.041% Terrasil.
Liquid Limit:-11.7
Plastic limit
Table 16 Plastic Limit of Red Soil with 0.041% Terrasil.
NO I II III
CONTAINER NO 1 2 3
Wt of cont+ wet of soil 33.5 32.5 31.2
Wt of cont. + dry soil 30 29.5 28
Wt of water 3.5 3 3.2
Wt of dry soil 13.5 13 11.5
Water content 25.9 23.07 27.8
Table 17 Proctor Test Compaction Test of Red soil with 0.041% Terrasil
Determination no I II III IV V
Wt of mould + compacted soil 7707 8446 9458 8458 5671
Wt of mould 5546 5546 5546 5546 5546
Volume of mould 2250 2250 2250 2250 2250
Wt of compacted soil 2161 2900 3912 3125 2912
bulk density 0.96 1.28 1.73 1.38 1.29
Dry density 0.91 1.16 1.50 1.16 1.075
Percentage of water use 6 10 15 18 20

Fig. 8 Compaction Curve for Red Soil with 0.041% Terrasil.
OMC:-10.18% and MDD:-1.91g/cm3
CBR
Table 18 Standard Load used in C.B.R Test.
Penetration Unit std. Load
(kgf/cm2)
Total std. Load
(kgf)
2.5mm 70 1370
5mm 105 2055
7.5mm 134 2630
10mm 162 3180
12.5mm 183 3600
Table 19 C.B.R test of Red soil with 0.041% Terrasil.
Soil Type Penetration C.B.R
Native 0.041% Terrasil
Red Soil @2.5 mm 1.64 2.79
@5 mm 1.42 2.46
Fig. 9 Load Penetration Curve for C.B.R Test of Red soil with 0.041% Terrasil.

Black cotton soil
Liquid limit
Table 20 LL B.C Soil with 0.041% Terrasil.
N0 I II III
Container no 1 2 3
Mass of container + dry soil(g) 25 26.5 23
Mass of water (g) 4 5.5 3
Mass of oven dry soil (g)(W2) 8.5 10 6.5
Water content (%) 47 55 46
Fig. 10 Flow Curve for B.C soil with 0.041% Terrasil.
Liquid Limit:- 51.14
Plastic limit
Table 21 PL B.C soil with 0.041% Terrasil.
NO I II III
CONTAINER NO 1 2 3
Wt of cont+ wet of soil 25 26 26.5
Wt of cont. + dry soil 23.5 24.5 24.3
Wt of water 1.5 1.5 1.5
Water content 21.42 `18.75 23.80
Table 22 Compaction Test of B.C soil with 0.041% Terrasil.
Determination no I II III IV
Wt of mould + compacted soil 9543 9728 9941 9812
Wt of mould 5546 5546 5546 5546
Volume of mould 2250 2250 2250 2250
Wt of compacted soil 3997 4182 4395 4266
bulk density 1.77 1.85 1.95 1.89
Dry density 1.63 1.68 1.69 1.61
Percentage of water use 8 10 15 17

Fig. 11 Compaction Curve of B.C soil with 0.041% of Terrasil.
OMC:- 14.5 and MDD:-1.692
CBR
Table 23 Standard Load Used in C.B.R Test.
Penetration Unit std. Load
(kgf/cm2)
Total std. Load
(kgf)
2.5mm 70 1370
5mm 105 2055
7.5mm 134 2630
10mm 162 3180
12.5mm 183 3600
Table 24 C.B.R test of B.C soil with 0.041% Terrasil.
Soil Type Penetration C.B.R
Native 0.041% Terrasil
Black Cotton
Soil
@2.5 mm 1.64 10.641
@5 mm 1.42 20.175
Fig. 12 Compaction Curve of B.C soil with 0.041% of Terrasil

IV. RESULTS AND DISCUSSION
4.1 General
This chapter includes the comparison between
conventional and chemical stabilisation for both
red and black cotton soil and all the comparison are
shown in the form of tables and graph.
4.2 Red Soil
Liquid limit
Table 25 Comparison Between Conventional &
Chemically Treated Red soil For LL.
Red soil Liquid
limit
Conventional 38.5%
Chemical 11.7%
Fig. 13 Comparison Of Flow Curves Between
Conventional & Chemically Treated Red soil For
LL.
Plastic limit
Chemically Treated Red soil For PL.
Red soil Plastic
limit
Conventional 33.5%
Chemical 25.59%
Chemically Treated Red soil For Proctor Test.
Red soil OMC MDD
Conventional 15.5% 1.17
gm/cm3
Chemical 10.18% 1.91
gm/cm3
Fig. 14 Comparison of Compaction Curves
between Conventional & Chemically Treated Red
soil for Proctor Test.
CBR
Chemically Treated Red soil For C.B.R.
Red soil C.B.R
Conventional
@2.5mm 8.37%
@5mm 9.47%
Chemical C.B.R
@2.5mm 16.1%
@5mm 21.6%
Fig. 15 Comparison of Load Penetration Curves
between Conventional & Chemically Treated Red
soil For C.B.R.
Black Cotton Soil
Liquid limit
Chemically Treated B.C soil For LL.
Black cotton
soil
Liquid
limit
Conventional 66.56%
Chemical 51.5%

Fig. 16 Comparison of Flow Curves Between
Conventional & Chemically Treated B.C soil For
LL.
Plastic limit
Chemically Treated B.C soil For PL.
Red soil Plastic
limit
Conventional 19.96%
Chemical 21.39%
Table 31 Comparision between Conventional &
Chemically Treated soil for Proctor Test.
Black cotton
soil
OMC MDD
Conventional 10.25% 1.7
gm/cm3
Chemical 14.5% 1.692
gm/cm3
Fig. 17 Comparison of Compaction Curve between
Conventional & Chemically Treated B.C soil for
Proctor Test.
C.B.R
Chemically Treated B.C. soil For C.B.R.
`Black cotton
soil
C.B.R
Conventional
@2.5mm 8.69%
@5mm 7.78%
Chemical C.B.R
@2.5mm 10.84%
@5mm 20.17%
Fig. 18 Comparison of Load Penetration Curves
between Conventional & Chemically Treated B.C
soil for C.B.R.
V. CONCLUSIONS
From laboratory results it was concluded that
1. Chemical stabilization had more CBR value
than conventional method of soil stabilization.
2. Chemical stabilization required lesser
thickness of subgrade in comparison with
conventional stabilization.
3. By adding terresil plasticity index reduced and
dry density increases.
4. Chemical stabilization was more economical
than conventional stabilization.
REFERENCES
[1]. P. Venkaramuthyalu et al “ study on
performance of chemically stabilized
expensive soil ‘’ IJAET jan 2012
[2]. R. saravan et al “A study on soil
stabilization of clay soil using flyash ‘’
International Journal of research in civil
engineering architecture & Design ‘’ vol. 1
Issue 2 oct -dec 2013 pp 333
[3]. Ankit negi et al “Soil stabilization using
lime ,International Journal of Innovative in
Science Engineering & Technology vol. 2
Issue -2 feb. 2013
[4]. Waseim azzam et al “Durability of
expansive soil using advanced nano
composite stabilization , International
journal of Gemate sept 2014 vol 7 no. 1 pp.

927 geotech const. mat. & Envirnonment
ISSN 2186 -2982(P) 2186-2990 . Japan
[5]. Nandan A. Patel, Prof.C. B. Mishra, Mr.
Vasu V. Pancholi, “Scientifically Surveying
the usage of terrasil chemical for soil
stabilization”, International Journal of
Research in Advent Technology, Vol.3,
No.6, June 2015
[6]. Monika Malhotra et al “ stabilization of
expansive soil using low cost material’’,
International Journal of engineering &
Innovative Technology (IJEIT) VOL. 2
Issue 11 may 2013
[7]. Olanlyan et al “ soil stabilization techniques
using sodium hydroxide additives ‘’
International Journal of Civil &
Environment engineering IJCEE vol . 2 No.
6
[8]. M. K. Gueddouda et al “ Chemical
stabilization of expansive days from Algeria
‘’ Global journal of researches in
engineering vol. II Issue 5 july 2011
[9]. Onyelowe ken c’ et al “ A Comparitive
review of soil modification Method ‘’ A
PRN journal of Earth sciences vol. 1 no. 2
nov. 2012
[10]. Faisal ali “ stabilization of Residual soil
using Liquid chemical” EJGW volume 17
(2012) bund -B
[11]. Soil Mechanics and Foundations . By-
Dr.B.C Punmia, Ashok Kumar Jain & Arun
Kumar Jain.

Efficient Way to Improve Subgrade Property of Pavement by Chemical Stabilization

More Related Content

What's hot (20)

Viewers also liked (15)

Similar to Efficient Way to Improve Subgrade Property of Pavement by Chemical Stabilization (20)

Recently uploaded (20)

Efficient Way to Improve Subgrade Property of Pavement by Chemical Stabilization