Experimental Study on Strength Behaviours of Clayey Soils by Using
Lime and Bagasse Ash
Wint Thiri Maw#1, Htay Win*2, Nu Nu Win#3
#
Department of Civil Engineering, Yangon Technological University
Insein Township, Yangon, Myanmar
1wintthirimawytu@gmail.com
Abstract – In this paper, two different natural clayey soils –
CL, CH are mixed with lime only and lime-bagasse ash to
analyse the improvement of the strength of soils. Yangon
Technological University (YTU) soil is CL – Lean Clay and
North Dagon (ND) soil is CH – Fat Clay. Bagasse, the fibrous
residue of sugarcane straws, is cheap and eco-friendly. By
using bagasse ash, disposal problems can be reduced. A lot of
admixture of soils with different percentages of lime and
bagasse ash were defined and modelled. The various
laboratory tests for this research are physical tests such as
moisture content, free swell ratio, specific gravity, sieve
analysis, hydrometer, Atterberg’s limit tests- liquid limit,
plastic limit and shrinkage limit and mechanical tests such as
standard proctor compaction test, California bearing ratio
test (CBR). This research includes lime and bagasse ash ratio
of 4%lime-6%bagasse ash (L4B6), 4%lime-8%bagasse ash
(L4B8), 4%lime-10%bagasse ash (L4B10), 6%lime6%bagasse ash (L6B6), 6%lime-8%bagasse ash (L6B8),
6%lime-10%bagasse ash (L6B10) for YTU soil and 4%lime6%bagasse ash (L4B6), 4%lime-8%bagasse ash (L4B8),
4%lime-10%bagasse ash (L4B10), 6%lime-4%bagasse ash
(L6B4), 6%lime-6%bagasse ash (L6B6), 6%lime-8%bagasse
ash (L6B8) for ND soil. At first, two different soils are mixed
with L4, L6, L8 and L10. The CBR strengths are very low at
natural condition. The CBR values increase remarkably by
adding lime content but CBR values decrease at L10. At 8%
addition of lime, the CBR strengths of two soils are the best.
Therefore, B6 and B8 were added to L4 and L6 to reduce the
lime per cent and to get the same strengths of L8. The CBR
strengths of lime and bagasse ash ratio are better than
original soils. However, CBR strength of ND soils - L6B8 does
not develop like L6B6. Therefore, B4 was re-mixed to this L6
of ND soil. This study gives the effective ratio of lime –
bagasse ash to stabilize the clayey soils.
bad smell, breeding ground for insects and clogging of
drainage system. Bagasse ash is re-use and re-cycle of
waste and then it can reduce harmful traditional stabilizers.
Bagasse ash can be reduced emitting of additional CO2
because bagasse ash is already available and making
cement emit CO2 from the industry into the atmosphere.
Today, using waste materials - Bagasse ash as partial
replacement of cement making eco efficient concrete is
called Green Concrete.
The combination of bagasse ash and hydrated lime is
more effective than bagasse ash only in controlling the
strength characteristics of clay. Moreover, geotechnical
engineering constructions such as pavement foundations,
lightweight fill in road embankments, lightweight backfill
behind retaining walls, highway construction and fibre
reinforcing materials as a replacement for foundation will
be used. This paper aims to analyse the physical and
mechanical properties of local clayey soils, to get better
knowledge of optimum lime and bagasse ash content and to
improve the strength of local clayey soils.
II. MATERIALS AND EXPERIMENTAL PROGRAM
The two soils are taken as disturbed samples from the
depth of 2 feet. The two soils are burnt 24hrs in oven to
know moisture content. And Free Swell Ratio test (FSR)
was performed. The natural soils were performed Specific
Gravity test, Sieve analysis test, Hydrometer test and Index
Properties test such as Liquid limit, Plastic limit and
shrinkage limit. From the results, these two soils can be
analysed whether they are different soil samples or not.
Soils are classified by Unified Soil Classification System
(USCS). After this, the natural soils are mixed with lime
and lime-bagasse ash. These natural soils and treated soils
were performed Standard Proctor Compaction test. By
using Optimum Moisture Content from compaction test,
CBR (unsoaked) and (soaked) was carried out to determine
the strength behaviours of clayey soils. Finally, physical
tests of treated soils were performed.
Keywords – Clayey Soils, Lime, Bagasse ash, Strengths,
Compaction, CBR, UCS
I. INTRODUCTION
Weak deposits such as clayey soils are characterized by
low bearing strength and shear strength. Clay may cracks
and damage on pavement, road ways, building foundations
or any other civil engineering construction projects and
need maintenance cases. So, to ensure safety and stability
for the buildings, infrastructures, roads and dam, preconstruction treatment of this soil is essential.
At present, the stabilizing chemicals like lime and
cement are becoming expensive. Generally, the properties
of clay are researched by mixing lime and cement with
different ratios and tests. So, we should test cheap bagasse
ash which will be one of the good stabilizing agents for
clay. In addition, the clayey soil strengths will improve by
using waste materials like bagasse ash for soil stabilization.
Sugarcane is abundantly available in tropical region.
Bagasse ash, by-product from sugar mills, has a substantial
amount of amorphous silica which can react with lime. If
sugarcane straws are stockpiled, this can cause serious
environmental hazard problems such as causing fire and
A. Soil
Clayey soils are easy to shrinkage and more difficult to
have its strength, hold a lot of water and it can become
waterlogged. The first soil sample was taken from Yangon
Technological University (YTU) campus, Insein Township
and the second soil sample was taken from North Dagon
(ND) Township. YTU soil is yellow colour and ND soil is
light black colour. The soils retained on #200 sieve are
tested with EDX. Main per cents of quantitative results of
EDX are shown in Table І and Table ІІ. The major oxide
forms of both soils are same and YTU soil has higher SiO 2
than ND soil.
1
for 24hr. The bagasse ash burnt with 110 ̊ C gives lowest
loss of carbon content – 5.28% and more SiO2. Therefore,
this ash is acceptable for test. Quantitative results of EDX
are shown in Table V.
TABLE I
YTU SOIL
Analyte
SiO2
Fe2O3
Al2O3
K2O
Result
37.467%
29.346%
18.702%
11.696%
TABLE V
110 ̊ C, 24HR BURNT BAGASSE ASH
Analyte
SiO2
K2 O
Al2O3
CaO
Fe2O3
SO3
MnO
ZnO
TiO2
Rb2O
SrO
CuO
Y2 O3
TABLE IIІ
ND SOIL
Analyte
Al2O3
SiO2
Fe2O3
K2O
Result
35.057%
32.009%
17.929%
12.669%
Characteristics of natural soils are shown in Table ІІІ
and Table ІV. Classifications of two soils are carried out
Unified Soil Classification System (USCS).
Result
43.392%
24.594%
17.910%
8.980%
1.916%
1.528%
0.726%
0.342%
0.214%
0.206%
0.103%
0.076%
0.012%
TABLE IIIІІ
CHARACTERISTICS OF YTU SOIL
Characteristics
Gravel (%)
Sand (%)
Silt/Clay (%)
Natural water content (%)
Liquid limit (%)
Plastic limit (%)
Plasticity index (%)
Linear shrinkage (%)
Specific gravity
Free Swell Ratio
Group Symbol
Group Name
Value
1.06
6.48
92.46
25.17
48
22.64
25.36
6.03
2.69
1.38
CL
Lean Clay
C. Lime
Lime, one of the traditional and chemical stabilizers, is
the effective method for ground improvement. It is widely
used in construction. It stabilized bases and sub-bases form
a water resistant barrier which stops penetration of rain
water. The lime amount of 5 to 10% is generally used for
more than 50% of silt-clay fraction. Therefore, 4, 6, 8, 10%
of lime was used in this study. Quantitative results of EDX
are shown in Table VІ.
TABLE VІ
LIME
Analyte
CaO
Al2O3
Fe2O3
SrO
TABLE IVV
CHARACTERISTICS OF ND SOIL
Characteristics
Gravel (%)
Sand (%)
Silt/Clay (%)
Natural water content (%)
Liquid limit (%)
Plastic limit (%)
Plasticity index (%)
Linear shrinkage (%)
Specific gravity
Free Swell Ratio
Group Symbol
Group Name
Value
0.24
4.02
95.74
38.33
51.8
21.03
30.77
6.8
2.7
1.39
CH
Fat Clay
Result
79.456%
20.331%
0.146%
0.067%
III. TEST RESULTS AND DISCUSSION
Treated specimens were prepared by mixing the soil
with lime and bagasse ash with various ratios.
A. Atterberg’s limit Test
The comparison of various results - Liquid limit(LL),
Plastic limit(PL), Plasticity Index(PI) and Shrinkage
limit(SL) of YTU soil and ND soil are shown in Fig.1 and
2.
YTU soil has lower water content, shrinkage and PI
value than ND soil. Moreover, specific gravity and FSR are
nearly same. As a result, two soils are high plasticity and
low FSR.
B. Bagasse Ash
The natural sugarcane ash was obtained from the local
sugar mills and put in the open atmosphere. The bagasse
ash was burnt in oven with different temperatures and
different hours – 800 ̊ C for 4hr, 850 ̊ C for 5min, 110 ̊ C
2
Fig. 1 Atterberg’s limit test results of YTU soil
MDD and OMC of L8 of two soils are not very different
too much.
Fig. 2 Atterberg’s limit test results of ND soil
Fig. 4 Lime Vs Water content
According to the Figures, the liquid limit (LL) and
plastic limit (PL) values are flocculation. LL of L4 for two
soils is the highest and that of L6 is the lowest. This shows
that L4 absorbs a lot of water. The PL of L4 for YTU soil
and L8 for ND soil are higher than any other. The PI of
both soils decreases steadily with the addition of lime
content. This shows that they are more fragile and increase
workability. The SL of YTU soil rises rapidly from L0 to
L10. The SL of ND soil increases from L0 to L4 and then
becomes stable. The reduction in PI increases SL, in other
word, increases volumetric changes.
B. Specific Gravity Test
The comparison of Specific Gravity (sp.gr) test results is
described in Fig. 3. In general, sp.gr results of clayey and
silty soils are ranging from 2.6 to 2.9. Therefore, sp.gr of
natural CL and CH soil are 2.69 and 2.7. The common
mineral for two soil is Montmorillonite. The other sp.gr of
two soils mixed with lime content lies around 2.0.
Fig. 5 Lime Vs Dry density
2) Soils mixed with lime – bagasse ash
The OMC and MDD results of L0B0, L4B6, L4B8,
L4B10, L6B6, L6B8 and L6B10 for YTU soil can be
compared in Fig. 6 and 7. The addition of bagasse ash has a
remarkable effect on compaction. The OMC of L4B6 and
L6B6 increases slightly but L4B8 and L6B8 decreases
significantly. Again, the OMC of L4B10 and L6B10 soil
rocketed to nearly 29% and 27%. But MDD drops
dramatically to 88lb/cu.ft.
Fig. 3 Sp.gr results of YTU soil & ND soil
C. Standard Proctor Compaction Test
Compaction test results of maximum dry density (MDD)
and optimum moisture content (OMC) are shown in Figure.
1) Natural soil and Soils mixed with lime
The MDD and OMC in Fig. 4 and 5 have flocculation
with the addition of lime content from 0% to 10%. The
natural two soils have peak MDD of over 100 lb/cu.ft. The
lowest OMC of YTU soil is L8 and ND soil is L6. But both
soils have highest OMC at L10 with the lowest MDD. The
Fig. 6 Lime-Bagasse Ash Vs Water content
3
D. California Bearing Ratio (CBR test)
The CBR results of (unsoaked and soaked) of the two
soils are shown in Fig. 10 to 15.
According Fig. 10 and 11, the CBR strengths (unsoaked)
of natural two soils are above 5%. By mixing lime, CBR
strengths (unsoaked) increase with the maximum strength
observed at L8. The soaked conditions also rise with
flocculation. The peak values of CBR (soaked) are L10 for
YTU soil and L6 for ND soil. Therefore, L4 and L6 are
mixed with bagasse ash (4% to 10%).
Fig. 7 Lime-Bagasse Ash Vs Dry Density
The variation results of ND soils for L4B6, L4B8,
L4B10, L6B4, L6B6 and L6B8 can be shown in Fig. 8 and
9. The OMC of L0B0 and L4B6 have no change. However,
the OMC of L4B6 to L4B10 increases rapidly but MDD
decreases significantly. The OMC of L4B4 to L4B8 is
stable. The OMC of L6B6 to L6B10 rises sharply but MDD
has same behaviour of YTU soil.
Fig. 10 CBR of YTU soil mixed with lime
Fig. 11 CBR of ND soil mixed with lime
The YTU soil mixed with lime-bagasse ash content has
its peak value at L6B8 as shown in Fig. 12 and 13. The ND
soil mixed with lime-bagasse ash content also has optimum
value at L6B6 as shown in Fig. 14 and 15. The CBR
strengths (soaked) of both soils gain higher values than
CBR (unsoaked).
Fig. 8 Lime-Bagasse Ash Vs Water content
Fig. 12 CBR (unsoaked) of YTU soil mixed with lime-bagasse ash
Fig. 9 Lime-Bagasse Ash Vs Dry Density
4
2.
3.
4.
5.
Fig. 13 CBR (soaked) of YTU soil mixed with lime-bagasse ash
6.
7.
Fig. 14 CBR (unsoaked) of ND soil mixed with lime-bagasse ash
8.
Sp.gr values of soil mixed with lime are lower
than that of natural soil.
It is found that natural YTU and ND soils are low
CBR values whereas L8 is the best for both CL
and CH soil. For unsoaked condition, CBR
strengths of L8 are about 2.5 times greater than
that of L0. For soaked condition, CBR strengths of
L8 are about 9 times greater than that of L0.
It is also investigated that two soils mixed with
bagasse ash to L4 do not have effective value like
L6.
However, L6B8 for CL soil and L6B6 for CH soil
have better remarkable results than L8 for CL, CH
soil. For unsoaked condition, CBR strengths of
L6B8 are about 3 times greater than that of L0.
CBR strengths of L6B6 are about 2.5 times greater
than that of L0.For soaked condition, CBR
strengths of L6B8 are about 5 times greater than
that of L0. CBR strengths of L6B6 are about 12
times greater than that of L0.
Moreover, CBR strengths (soaked) of L6B8 and
L6B6 are better than that of L8. However, CBR
strengths (unsoaked) of two soils mixed with lime
and mixed with lime-bagasse ash are nearly same.
This analysis shows that the natural soils are
suitable only for subgrade but soils mixed with
lime-bagasse ash can be used for subbase.
As a result, Bagasse ash can be partially replaced
and reduced lime content to improve strength in
clayey soil stabilization.
ACKNOWLEDGMENT
The author wishes to acknowledge Dr. Nyan
Myint Kyaw, Professor and Head of Civil Engineering
Department, Yangon Technological University, for
providing encouragement. Special thanks are also owed to
U Htay Win, Associate Professor, Department of Civil
Engineering, Yangon Technological University, for giving
helpful advices and comments in doing this paper. The
author also thanks to Daw Nu Nu Win, lecturer,
Department of Civil Engineering, Yangon Technological
University. I would like to acknowledge all the people who
encouraged and supported to me to complete successfully
during undertaking of this paper.
Fig. 15 CBR (soaked) of ND soil mixed with lime-bagasse ash
The peak CBR values of two soils mixed with lime-ash
are shown in Table VVІ and VVIІІ.
TABLE VVIIVIII
COMPARISON OF CBR STRENGTHS FOR YTU SOIL
REFERENCES
[1]
Unsoaked
Soaked
Natural
5.33
3.67
L8
14.33
18.44
L6B8
17.83
19.33
TABLE VIXІX
COMPARISON OF CBR STRENGTHS FOR ND SOIL
Unsoaked
Soaked
Natural
6.5
2.58
L8
16
20.11
[2]
L6B6
15.78
31.5
[3]
[4]
IV. CONCLUSIONS
The following can be concluded from this research.
1. Plasticity index (PI) for CL and CH soil slightly
decreases with the addition of lime. PI is inversely
proportional to SL for two soils.
[5]
5
Liet Chi Dang, Enhacing the Engineering Propertiesof Expansive
Soil Using Bagasse Ash and Hydrated Lime, International Journal
of GEOMATE, Sept., 2016, Vol. 11, Issue 25, pp. 2447-2454
Geotec., Const. Mat. & Env., ISSN: 2186-2982(Print), 21862990(Online), Japan
Liet Chi Dang, Influence of Strength and Mechanical Behaviour of
Bagasse Ash and Hydrated Lime Stabilized Expansive Soil, PhD
Candidate, School of Civil and Environmental Engineering,
University of Technology Sydney (UTS), Ultimo, NSW 2007,
Australia
Sadeeq, J. A, Effect of Bagasse Ash on Lime Stabilized Lateritic
Soil, Jordan Journal of Civil Engineering, Volume 9, No. 2, 2015
Eberemu, Adrian O., Compressibility Characteristics of Compacted
Lateritic Soil Treated with Bagasse Ash, Jordan Journal of Civil
Engineering, Volume 9, No. 2, 2015
A.T.Manikandan,
CONSOLIDATION
AND
REBOUND
CHARACTERISTICS OF EXPANSIVE SOIL BY USING LIME
AND BAGASSE ASH, IJRET: International Journal of Research in
Engineering and Technology, eISSN: 2319-1163 | pISSN: 23217308