By Tanisha Nayak

1. 1 | P a g e
Chapter 1
INTRODUCTION

2. 2 | P a g e
INTRODUCTION
1.1 GENERAL
Soil stabilisation means the improvement of stability or bearing power of the soil by the use of
controlled compaction, proportioning and/or the addition of suitable admixture or stabilisers. The basic
principles of soil stabilisation are:
 Evaluating the properties of given soil.
 Deciding the lacking property of soil and choose effective and economical method of soil
stabilisation.
 Designing the stabilised soil mix for intended stability and durability values.
Stabilisation can increase the shear strength of a soil and/or control the shrink-swell properties of a soil, thus
improving the load bearing capacity of a sub-grade to support pavements and foundations. Stabilisation can
be used to treat a wide range of sub-grade materials from expansive clays to granular materials. In wet
weather, stabilisation may also be used to provide a working platform for construction operations. These
types of soil quality improvement are referred to as soil modification. Benefits of soil stabilisation are higher
resistance values, reduction in plasticity, lower permeability, reduction of pavement thickness, elimination
of excavation, material hauling and handling, and base importation, aids compaction, provides all-weather
access onto and within projects sites. The determining factors associated with soil stabilisation may be the
existing moisture content, the end use of the soil structure and ultimately the cost benefit provided.
Soil stabilization using raw plastic bottles is an alternative method for the improvement of subgrade
soil of pavement. It can significantly enhance the properties of the soil used in the construction of road
infrastructure. Results include a better and longer lasting road with increased loading capacity and reduced
soil permeability. This new technique of soil stabilisation can be effectively used to meet the challenges of
society, to reduce the quantities of waste, producing useful material from non-useful waste materials that
lead to the foundation of sustainable society. It can be effectively used in strengthening the soil for road
embankments and in preparing a suitable base for the upper pavement structure. Since it increases the bearing
capacity of soil considerably, the land use can be increased. It can lower the road construction and
maintenance costs while increasing the overall quality of its structure and surface.

3. 3 | P a g e
Chapter 2
MATERIALS
AND
METHODOLOGY

4. 4 | P a g e
2.1 MATERIALS USED
To conduct this study, various materials such as
I. Lateritic soil
II. Plastic bottles (both cut and uncut)
III. Sea sand
IV. Synthetic threads
2.2 METHODOLOGY
For this study we have to do three test. They are
 Standard Proctor Compaction Test
 CBR test
 Plate Load test
The Standard Proctor Compaction tests were done to assess the amount of compaction and the water content
required in the field. The California Bearing Ratio test was conducted to determine the optimum amount of
plastic strips in soil. This is done by mixing soil with varying percentages (0.0%, 0.2%, 0.4% etc.) of plastic
strips in soil and the 4 day soaked CBR Value is obtained. Plate load tests were conducted with plain lateritic
soil, soil stabilised with full bottles, soil stabilised with bottles cut to two halves and soil stabilised with
optimum percentage of plastic strips. Load-settlement graphs for each plate load test were drawn. For each
load-settlement graph, the load corresponding to 4mm settlement was noted. The ultimate load and
corresponding settlement of the plate is also determined from the load- settlement graph plotted for various
test arrangements.
𝒅 𝒘 𝒘
Optimum Amount of
Plastic Strips
Plate load
test
CBR
Standard
Proctor
Compaction

5. 5 | P a g e
Chapter 3
RESULTS
AND
DISSCUSSION

6. 6 | P a g e
3.1 COMPACTION RESULTS
FIG-1 COMPACTION CURVE (source: Indian Geotechnical journals, page 490)
From the compaction curve, the maximum dry density and optimum moisture content were obtained
as 18.95kN/𝑚 and 11.22 % respectively. This is used for finding the bulk density of the soil filled in the
tank for plate load test. The California Bearing Ratio test was also carried out by mixing the soil with
optimum moisture content.
3.2 CBR RESULT
TABLE 1
FIG 2 ( Relation between CBR Value and percentage of plastic content )
% of Plastic
Content
CBR
Value
0 1.9
0.2 1.7
0.4 1.8
0.6 2.5
0.8 1.3
1 1.3
0, 1.9
0.2, 1.7
0.4, 1.8
0.6, 2.5
0.8, 1.3 1, 1.3
0
0.5
1
1.5
2
2.5
3
0 0.2 0.4 0.6 0.8 1 1.2
CBRVALUE
% OF PLASTIC CONTENT
CBR Value
CBR…

7. 7 | P a g e
It is observed from the test results that for soil mixed with waste plastic strips, soaked CBR values increased
from 1.967 to 2.479 with 0.6% of plastic and there after decreased. Hence the optimum percentage of plastic
strip in soil is found to be 0.6%. It was also observed that there was a reduction in the CBR value from 1.967
for plain soil to 1.687 on adding 0.2% plastic this is because the addition of small amount of plastic into soil
lead to a dispersed and disturbed structure to soil than that it was in its compact form. Also the optimum
moisture content was maintained the same so it also affected the decrease in the value.
3.3 PLATE LOAD TEST
TABLE 2
Tests done on
Settlement
(mm)
Corresponding
Load (kg)
Percentage variation
of load from plain soil
Plain soil 4 440
Sand filled bottles at D/B=0.67 4 585 33
Sand filled bottles at D/B=1 4 680 54.5
Bottles cut to halves at D/B=0.67 4 740 68.1
Bottles cut to halves at D/B=1 4 900 104.5
Soil mixed with optimum
percentage(0.6%) of Plastic strips 4 1200 172.7

8. 8 | P a g e
FIG 4 FIG 5
From Table 2, it can be inferred that the load carried corresponding to 4mm settlement is much more
for soil stabilised with plastic than that of plain soil and thus the there is considerable increase in bearing
capacity of the soil. The plastic bottles and bottle cut to halves gave more strength when kept at D/B=1 than
that at D/B=0.67.When load is applied, the distribution of load takes place as shown in Fig. 4.16 It is clear
that at D/B=0.67,only a portion of the plastic bottles become effective in carrying the load, while at D/B=1,
the whole layer contributes in taking the load. This may be the reason for the above phenomenon noted.
TABLE 3
Tests done on Final load (kg)
Final
settlement
(mm)
Percentage
variation of
settlement from
plain soil
Plain soil 1344.1 18.1 0
Sand filled bottles at D/B=0.67 1344.1 14.1 22%
Sand filled bottles at D/B=1 1344.1 13.8 23.70%
Bottles cut to halves at D/B=0.67 1344.1 13.4 26%
Bottles cut to halves at D/B=1 1344.1 10 44.70%
Soil mixed with optimum percentage(0.6%)
ofPlastic strips 1344.1 5.26 70.90%
0
100
200
300
400
500
600
700
800
ULTIMATELOAD(Kg)
Variations of ultimate
load for various test
arrangements
0.00
0.50
1.00
1.50
2.00
SETTLEMENT
Variations of settlement
corresponding to the
ultimate load for various test
arrangements

9. 9 | P a g e
From Table 3, it is evident that the final settlement for all cases of soil stabilised with plastic is much
less than that of plain soil. Decrease in settlement points to the increase in the bearing capacity of the soil.
The factors contributing to this increase are the position of bottles, arch action etc. While comparing the
percentage variations, it is clear that the maximum percentage decrease in settlement is that for the soil mixed
with optimum amount of plastic strips. In the case of soil stabilised with plastic bottles minimum settlement
is noted for the plastic bottles cut to halves at D/B=1; this may be due to arch action. It can also be noted that
there is not much difference in final settlements for the soil stabilised with sand filled bottles at D/B=0.67
and D/B=1, whereas there is considerable difference comparing the final settlements of the soil stabilised
with bottles cut to halves kept at the respective position.
The ultimate load and corresponding settlement of the plate is determined from the load- settlement
graph plotted for various test arrangements. It is obtained from the load and settlement corresponding to the
intersection of the tangents drawn to the initial and final straight portions of the curve obtained.
TABLE 4
Tests done on Ultimate load(kg) Corresponding settlement(mm)
Plain soil 360 1.60
Sand filled bottles at D/B=0.67 480 1.20
Sand filled bottles at D/B=1 560 1.60
Bottles cut to halves at D/B=0.67 600 1.20
Bottles cut to halves at D/B=1 760 1.60
Soil mixed with optimum
percentage(0.6%) of Plastic strips 720 0.60
From Table 4 and Fig. 4, it can be noted that the ultimate load increased for the various cases of the
soil stabilized with plastic than that for the plain soil. This increase in load carrying capacity is due to the
efficiency contributed by the bottles that was intermixed to the plain soil. The reason for increased load for
D/B=1 when compared to D/B =0.67 is due to the variation in the distribution of load as stated earlier. It can
also be noted that when compared to plastic bottles filled with sand, bottles cut to halves carried much higher
load; this may be due to arch action.
It can also be noted from Table 4 and Fig.5 that, though the ultimate load carried by the soil stabilised
with bottles filled with sand and bottles cut to halves at D/B= 1 is higher than that for the plain soil, its
corresponding settlement remained same as that for the plain soil. This is due to the reason that in both cases
the soil is being filled similar to that of plain soil to a depth of 30cm (half the depth of tank). Thus the
immediate settlement of the soil remains the same. It is also seen that the ultimate load for soil mixed with
optimum amount of plastic strip is less than that of bottles cut to halves kept at D/B= 1, but when comparing
the corresponding settlements, the former one showed only 3/8th the settlement of that of the latter case.

10. 10 | P a g e
While comparing the test results, the arrangement which carried the maximum load with minimum settlement
is that for soil mixed with optimum amount of plastic. At the same time it can also be noted that soil stabilized
with bottles cut to halves kept at D/B=1 also carried considerable load. If we compare the quantity of waste
plastic required to get the desired results only a few bottles is sufficient when the soil is stabilised with sand
filled bottles (about 18 bottles for our test set up) and also for soil stabilised with bottles cut to halves (about
9 bottles for our test set-up). Whereas, the number of bottles which is necessary to stabilise the soil with
optimum amount of plastic strips were much higher (about 200 bottles for our test set-up). Thus the plastic
content in the soil is very much high when the strips are used.

11. 11 | P a g e
Chapter 4
CONCLUSION

12. 12 | P a g e
4.1 CONCLUSION
I. Using plastic bottles as a soil stabiliser is an economical and gainful utilization since there is
scarcity of good quality soil for embankments and fills.
II. Thus this project is to meets the challenges of society to reduce the quantities of plastic waste,
producing useful material from non-useful waste materials that lead to the foundation of
sustainable society
Use of plastic products such as polythene bags, bottles, containers and packing strips etc. is increasing day
by day. The disposal of the plastic wastes without causing any ecological hazards has become a real challenge
to the present society. Thus using plastic bottles as a soil stabiliser is an economical and gainful utilization
since there is scarcity of good quality soil for embankments and fills. Thus this project is to meets the
challenges of society to reduce the quantities of plastic waste, producing useful material from non-useful
waste materials that lead to the foundation of sustainable society.

13. 13 | P a g e
REFFERENCE
1 Joseph Mariamma, “SOIL STABILIISATION USING RAW PLASTIC BOTTLES” proceedings of
Indian Geotechnical Conference, December 15-17, 2011, Kochi (Paper No. H-304)
2 Dr. H Babitharani, “Soil Stabilization using Plastic”, International Journal of Engineering
Technology Science and Research, Volume 4, Issue 9, ISSN 2394 – 3386
3. Arora, K. R. (2004). “Soil Mechanics and Foundation Engineering”. Standard Publishers
Distributors.
4. Kumar, M. A., Prasad, D. S. V. And Prasadaraju, G. V. R. (2009). “Utilisation of industrial waste in
flexible Pavement construction”. Electronic Journal of Geotechnical Engineering, Vol. 13
5. IS: 1888(1982), “Method of Load Test on Soils”. Indian Standards Institutions, New Delhi.