Soil stabilization is the permanent physical and chemical alteration of soils to enhance their physical properties. Stabilization can increase the shear strength of a soil and control the shrink-swell properties of a soil, thus improving the load-bearing capacity of a sub-grade to support pavements and foundations. Stabilization can be used to treat a wide range of sub-grade materials from expansive clays to granular materials. Stabilization can be achieved with a variety of chemical additives including lime, fly ash, and Portland cement, as well as by-products such as lime-kiln dust and cement-kiln dust. 1) Mechanical Soil Stabilization Technique: Dense and well graded material can be achieved by mixing and compacting two or more soils of different grades. Addition of a small amount of fine materials such as silts or clays enables binding of the non-cohesive soils which increases strength of the material. Factors affecting the mechanical stability of mixed soil may include: The mechanical strength and purity of the constituent materials  The percentage of materials and its gradation in the mix  The degree of soil binding taking place  The mixing, rolling, and compaction procedures adopted in the field  The environmental and climatic conditions 2) Compaction Soil Stabilisation Technique: Uses mechanical means for expulsion of air voids within the soil mass resulting in soil that can bear load subsequently without further immediate compression. Dynamic compaction is one of the major types of soil stabilization; in this procedure, a heavyweight is dropped repeatedly onto the ground at regular intervals to quite literally pound out deformities and ensure a uniformly packed surface. 1) Moisture Content. 2) Specific gravity of soil. 3) Atterberg’s limit. 4) Liquid limit. 5) Particle size distribution. 6) Preparation of reinforced soil sample. 7) Determination of shear strength. 1) Moisture Content Soil tests natural moisture content of the soil is to be determined. The natural water content also called the natural moisture content is the ratio of the weight of water to the weight of the solids in a given mass of soil. 2) Specific gravity of soil. The specific gravity of soil is defined as the unit weight of the soil mass divided by the unit weight of distilled water at 4°C. 3) Atterberg’s limit Atterberg's limits are a set of tests used in soil mechanics to determine the plasticity and compressibility characteristics of soil 1. It improves the strength of the soil, thus, increasing the soil bearing capacity. 2. It is a lot of economical each in terms of price and energy to extend. 3. Bearing capacity of the soil instead of going for deep foundation or raft foundation. 4. It offers more stability to the soil in slopes or other such places. 5. Sometimes soil stabilization is also stop soil erosion or formation of mud, which is extremely helpful particularly in dry and arid weather.

1. Plastic
As Soil Stabilizer
Ranit Sarkar

2. INTRODUCTION
 Soil stabilization is the permanent physical and chemical alteration of soils to enhance their
physical properties.
 Stabilization can increase the shear strength of a soil and control the shrink-swell properties of a
soil, thus improving the load-bearing capacity of a sub-grade to support pavements and
foundations.
 Stabilization can be used to treat a wide range of sub-grade materials from expansive clays to
granular materials.
 Stabilization can be achieved with a variety of chemical additives including lime, fly ash, and
Portland cement, as well as by-products such as lime-kiln dust and cement-kiln dust.
Plastic As Soil Stabilizer
Ranit Sarkar

3. Types of Soil Stabilization Techniques
1) Mechanical Soil Stabilization Technique:
 Dense and well graded material can be achieved
by mixing and compacting two or more soils of
different grades.
 Addition of a small amount of fine materials
such as silts or clays enables binding of the non-
cohesive soils which increases strength of the
material.
 Factors affecting the mechanical stability of
mixed soil may include:
• The mechanical strength and purity of the
constituent materials
• The percentage of materials and its
gradation in the mix
• The degree of soil binding taking place
• The mixing, rolling, and compaction
procedures adopted in the field
• The environmental and climatic conditions
2) Compaction Soil Stabilisation Technique:
 Uses mechanical means for expulsion of air voids
within the soil mass resulting in soil that can
bear load subsequently without further
immediate compression.
 Dynamic compaction is one of the major types of
soil stabilization; in this procedure, a
heavyweight is dropped repeatedly onto the
ground at regular intervals to quite literally
pound out deformities and ensure a uniformly
packed surface.
Ranit Sarkar

4. Types of Soil Stabilization Techniques
3) Chemical Soil Stabilisation Technique:
 Chemical stabilizers, also known as soil
binders or soil palliatives, provide temporary
soil stabilization.
 They are readily applicable to the surface of
the soil, can stabilize areas that cannot
establish vegetation, and provide effective
protection from wind and stormwater
erosion.
4) Polymer/Alternative Soil Stabilisation
Technique:
 Methods for introducing polymers into soils
include mixing, injecting, spraying, and
grouting.
 Liquid polymers, sold as concentrated
solutions, can be applied deep within the soil
through pressure injection or applied directly
to uncompacted soil.
 The prerequisites for polymer stabilization
include:
•The polymer must be adhesive to soil
particles in the presence of water
•Internal cohesion of the polymer is key
•Workability at high humidity and low
ambient temperatures
•Miscibility with water to produce a low
viscosity liquid

5. Types of Soil Stabilization Techniques
4) GRT’s Soil Stabilization Techniques
 Global Road Technology and its innovative polymer-based products are
helping organizations revolutionize the way they build their infrastructure.
 When it comes to the different soil stabilization methods, GRT products
simply stand head and shoulders above competing products.
 GRT’s engineered soil solutions work best for a wide range of applications that
include – soil stabilization for dirt roads, haul roads, stockpiles, highways, etc.

6. METHODOLOGY
1) Moisture Content. 2) Specific gravity of soil. 3) Atterberg’s limit.
4) Liquid limit. 5) Particle size distribution. 6) Preparation of
reinforced soil sample. 7) Determination of shear strength.
1) Moisture Content
Soil tests natural moisture content of the soil is to be
determined. The natural water content also called the natural
moisture content is the ratio of the weight of water to the
weight of the solids in a given mass of soil.
2) Specific gravity of soil.
The specific gravity of soil is defined as the unit weight of the
soil mass divided by the unit weight of distilled water at 4°C.
3) Atterberg’s limit
Atterberg's limits are a set of tests used in soil mechanics to
determine the plasticity and compressibility characteristics of
soil

7. METHODOLOGY
4) Liquid limit
The liquid limit of a soil is the water content at which the soil
behaves practically like a liquid, but has small shear strength.
5) Particle size distribution
Particle size distribution, also known as gradation, refers to the
proportions by dry mass of a soil distributed over specified particle-
size ranges.
6) Preparation of reinforced soil sample
1) Step 1) Excavate soil, 2) Step 2) Collect sand ,3) Step 3) Melt plastic, 4)
Step 4) Mix soil with sand, 5) Step 5) Mix melted plastic with soil and sand.
7) Determination of shear strength
Shear strength is a term used in soil mechanics to describe the magnitude of
the shear stress that a soil can sustain

8. 1. It improves the strength of the soil, thus, increasing the soil bearing capacity.
2. It is a lot of economical each in terms of price and energy to extend.
3. Bearing capacity of the soil instead of going for deep foundation or raft foundation.
4. It offers more stability to the soil in slopes or other such places.
5. Sometimes soil stabilization is also stop soil erosion or formation of mud, which is
extremely helpful particularly in dry and arid weather.
6. Stabilization is also done for soil water-proofing; this prevents the seepage in soil
and hence helps the soil from losing its strength.
7. It helps in reducing the soil volume modification because of modification in
temperature or wetness content.
8. Stabilization improves the workability and also durability of the soil.
Advantages of Plastic as a Soil Stabilizer

9. As we all know plastic releases many harmful chemicals into the surrounding soil, which can seep into
groundwater or other surrounding water sources, and also the ecosystem. This can cause a range of
potentially harmful effects on the species that drink the water. When plastic particles break down, they gain
new physical and chemical properties, increasing the risk that they will have a toxic effect on organisms.
 Non-biodegradableNon-biodegradable means it cannot decompose naturally which can have long-
lasting negative effects on the environment.
 Leaching of chemicalsPlastics releases many harmful chemicals into the soil, which can then
contaminate the surrounding groundwater and soil.
 Soil fertilityPlastic can prevent air and water from reaching the soil, which can make it difficult for
plants to grow and thrive.
 WildlifePlastic waste can also harm wildlife by causing entanglement, ingestion, and other types of
injury.
Overall, while plastic can be an effective soil stabilizer in some cases, it is important to consider the
potential environmental concerns associated with its use.
Environmental concern

10. Alternative materials and methods that are more sustainable and eco-friendly for promoting healthy
and sustainable soil ecosystems.
 Biodegradable natural fibres
 Geotextiles
 Natural materials
 Soil-binding agents
Some examples of successful projects :
 Geotextiles in road constructionIn India, a project was undertaken to construct a road using
geotextiles as the primary soil stabilizer. The geotextiles were made of a synthetic fabric that was
designed to break down over time
 Jute and coir in slope stabilization  In Sri Lanka, a project was undertaken to stabilize slopes using jute
and coir fibers. The fibers were used to reinforce the soil and prevent erosion.
 Gravel in soil stabilizationIn the United States, a project was undertaken to stabilize soil using gravel.
The gravel was used as a base layer to stabilize the soil and improve the load-bearing capacity of the soil.
 Enzymes in soil stabilizationIn Germany, a project was undertaken to stabilize soil using enzymes. The
enzymes were added to the soil to improve the soil's stability and prevent erosion.
Alternative to Plastic

12. Case study 1:
Plastic Waste as Soil Stabilizer for Rural Roads of Tamil Nadu, India.
• The study aimed to evaluate the effectiveness of plastic waste as a soil stabilizer for rural roads
• The researchers used shredded plastic waste, consisting of high-density polyethylene (HDPE) and low-
density polyethylene (LDPE), as a soil stabilizer.
laboratory tests conducted to determine the optimal
percentage of plastic waste to be added to the soil.
Conclusion:
adding 2% of shredded plastic waste to the soil improved the
soil strength and reduced the soil's susceptibility to moisture.
Field study by constructing a 1.5-kilometer stretch of road using a mix
and was subjected to traffic and weather conditions for six months.
Results:
The plastic waste-stabilized road had better stability, reduced
deformation, and improved resistance to moisture compared to the
control road constructed using only soil.
1
2
Ranit Sarkar

13. Benefits and Limitations
• it is an eco-friendly approach that helps to reduce plastic waste in the environment
• the use of plastic waste as a soil stabilizer is a cost-effective approach.
• Potential leaching of chemicals from the plastic into the soil. The long-term effects of plastic waste
on soil health and the environment are still unknown, and further research is needed to address this
concern

14. Case Study 2 :
Plastic Geocells for Soil Stabilization in a Residential Development, the A1 motorway in the United
Kingdom
Background
• A residential development in a
suburban area was facing
challenges due to soil instability
caused by heavy rainfall and soil
erosion
Solution
• The local authorities decided to
use plastic geocells for soil
stabilization. The geocells were
made of high-density
polyethylene (HDPE) and were
designed to stabilize the soil
and prevent erosion.
Ranit Sarkar

15. Implementation
Site Preparation: The area was cleared of any debris and the soil was levelled to
create a smooth surface. The soil was compacted to increase its stability.
Installation of Plastic Geocells:
1. laid over the soil in a grid pattern.
2. The geocells were anchored to the soil using stakes and then filled with gravel and
soil.
3. Distributed the load of the houses and the infrastructure evenly, which reduced the
risk of soil movement
Construction:
After the plastic geocells were installed, the construction of the houses and
infrastructure began.
The use of plastic geocells for soil stabilization proved to be effective. The plastic
geocells prevented soil erosion and provided a stable base for structure installation. The
geocells were cost-effective compared to traditional materials such as concrete or steel.
The construction crew was able to complete the project on time and within budget.

16. Plastic as a soil stabilizer has several advantages,
1. including its low cost,
2. availability, and
3. effectiveness in improving soil stability.
Plastic as a soil stabilizer has several disadvantages
1. The primary concern is the negative environmental impact of plastic.
2. Plastic is non-biodegradable, meaning it takes hundreds of years to decompose, and during
this time, it can cause significant damage to the environment.
The environmental impact of using plastic as a soil stabilizer must be considered when
selecting a method for a specific project.
Alternative methods of soil stabilization
1. using natural materials like lime, cement, and biodegradable fibers. Lime and cement are
effective in soil stabilization,
2. Biodegradable fibers, on the other hand, are a cost- effective and environmentally friendly
option that can be used as an alternative to plastic.

17. THANK
YOU