[9] Main methods of soil stabilization with different materials use

What is soil stabilization?

The soil stabilization is the system of improving the dependability or bearing limit of soil by the utilization of controlled compaction, proportioning and additionally the option of reasonable admixtures or stabilizers is named as Soil adjustment or "The strategy for improving the building properties of soil by embracing different adjustment procedures is named as Soil adjustment." 
In the process of soil stabilization, the soil is treated in such a manner so as to improve or alter its physical conditions or properties to make it more stable and durable. Soil stabilization becomes necessary when a highway and any type of structure is required to be built over weak soil or soil of poor bearing capacity. It is a necessary part of increase the durability and stability of the structure and building.

What is the need for soil stabilization?

1. To increase the compressive strength of the soil.
2. The stabilization also increases the shear strength and bearing capacity of the soil.
3. To increase resistance to softening action of water. reduction in plasticity
4. The stabilization also improves the strength of soil against the adverse effects of moisture.
5. The stabilization also increases the flexibility of soil to bear the wheel loads without deformation and cracking.
6. To allow clay or other soft soils to be used as subgrade material after treatment.
7. To improve the stability and durability of any type of structure.

What are the Methods of soil stabilization?

The different methods are mainly used for soil stabilization depend upon the type of soil. The soil stabilization is a very important role to start constructing any type of structure and highways. Soil Stabilization Methods with Different Materials are the following given below.

1. Soil stabilization by mechanical method
2. Soil Stabilization by Cement
3. Soil Stabilization by Lime
4. Soil Stabilization with Bitumen
5. Chemical Stabilization of Soil
6. Soil Stabilization by Grouting
7. Electrical Stabilization of Soils
8. Soil Stabilization with fly ash
9. Soil Stabilization by Geotextiles and Fabrics

1. Mechanical stabilization

The method of adding deficient material in the soil or proportioning the soil properly to make it a well-graded soil is termed as mechanical stabilization. It is generally properly done with the machine. If the soil is sandy in nature, clay particles are added to it whereas if the soil is fine-grained, the requisite quantity of sand is added. The simple way,  the strength & durability can be increased without adding any chemical through the following methods are given below points use in mechanical stabilization of soil.

• Compaction 
• Consolidation
• Well Grading (mixing of coarse-grained & fine-grained.)

2. Cement stabilization

In this method of stabilization, cement is used in small proportions to modify its properties. To increase the strength and durability of all types of soil except organic clays cement slurry can be injected under pressure in the pores of soil which is called cement grouting. The cement requirement is nearly 5% for sands and 15% for clays of the volume of soil.


3. Lime stabilization

In this technique, lime is used for soil stabilization instead of cement. Hydrated lime is used to stabilize highly plastic clays (Black Cotton Soils). Lime may be used alone or in also combination with cement, bitumen, or fly ash. The sandy soils can also be stabilized with these combinations. Lime has been a wide range of used for stabilizing the road base course and the subgrade. The lime is mainly altering the nature of the adsorbed layer and provides pozzolanic action. The volume of lime required is (4% to 6%) of the volume of the soil. In Lime Stabilization liquid limit decreases and plastic limit increases thus plasticity index decreases. Soil becomes more friable and workable, there is an increase in the OMC and a decrease in the maximum compacted density, but the strength and durability increase. Lime increases Unconfined compressive also increases substantially. 

4. Bitumen stabilization

In this method, the soil is treated with commonly used bituminous binders like cut back or emulsions. The object is to glue the soil particles together and improve the binding and waterproofing properties of soil. The bitumen, Tar, and Emulsion are used to stabilize granular soil deposits. It acts as a binding as well as a water repulsing agent. It is generally more used for pavement construction It is often used to stabilize the surface course of roads. 

5. Chemical stabilization

The chemical stabilizer methods, strength, and durability are increased by adding chemical admixtures compounds mixed with soil to improve the properties of soil. The main chemical and many other superplasticizers used for this method are following the given below.

Use of Calcium Chloride (CaCl₂) - It acts as a water repulsing agent, it is used to stabilize sands in base & sub-base course of roads.

Use of Sodium Silicate (NaSiO2) - Sodium silicate with calcium chloride is known as water glass. The mixture is injected in the soil which forms precipitation of silica get within pores of soil which reduces permeability & increases shear strength. Used in the sands.


6. Soil Stabilization by Grouting

It is a method of injecting a suitable grout or stabilizer in a liquid state into hard soils or rock formations. Grouting reduces permeability and compressibility and increases the strength of the soil. The holes are drilled into the soil at regular intervals and grouting materials like cement slurry, liquid bitumen or chemicals may be used for injection. 


7. Electrical stabilization

It is also known as electro-osmosis. In this method, soil properties are altered by passing a direct current through them. With the current flow, the ion-exchange phenomenon occurs, fine particles of soil are damaged and the soil is consolidated. 


8. Flyash stabilization

In this method, the soil is treated with coal ash or fly ash obtained from thermal power plants to modify its properties. Flyash particles are fine-grained in nature and are very useful for the stabilization of granular soil. This technique of soil stabilization also comes to our rescue for providing an alternative way of solving the biggest problem of fly ash disposal. 

9. Geotextiles and (Membranes) stabilization

Geotextiles are artificial geosynthetics products of the poly materials having a small thickness (few mills). (1 Mill = 1/1000 inch) geotextiles are used to stabilize sloppy landfills. These are often used in earthen dams & retaining walls and other this type of structure.

Geosynthetics are human-made materials made from various types of polymers (Polyethylene, Polypropylene, Polyester, Nylon, Polyvinyl Chloride) used to enhance, augment and make possible cost-effective environmental, transportation and geotechnical engineering construction projects.

These products have a good vary of applications and are presently utilized in several civil, geotechnical, transportation, geoenvironmental, as well as roads, airfields, railroads, embankments, holding structures, reservoirs, canals, dams, erosion management, sediment management, lowland liners. lowland covers, mining, cultivation, and agriculture.

Know more about stabilization watch this video