Tuesday, 21 August 2018

5 Methods of Soil Stabilization-Mechanical,Chemical,Cement,lime,Bitumen

5 Methods of Soil Stabilization

Following 5 method are commonly used-
1.Mechanical soil Stabilization.
2.Soil-Cement Stabilization.
3.Soil-lime Stabilization.
4.Soil-Bitumen Stabilization.
5.Chemical Stabilization.
Methods of Soil Stabilization Are Described Below

1. Mechanical Soil Stabilization

5 Methods of Soil Stabilization
 In this method the stability of the soil is increased by blending the available soil with imported soil or aggregates so as to obtain a desired particle size distribution and by compaction of the mixture to achieve the desired density.

⇰ This method is generally adopted for construction of sub-base and base-course. It is also useful for construction of surface course of low cost roads such as village roads when the traffic and rainfall are low.

2. Soil-Cement Stabilization 

⇰ Soil-cement is an intimate mix of soil, cement and water which is well compacted to form a strong base course. Addition of cement in small proportion to soil improves its strength and modifies the properties of soil. 

⇰ Soil-cement stabilization can be used as a sub-base or base-course of all types of payments.But this method can not be used as surface course due to its poor resistance to abrasion and impact .

⇰ This method is costly and needs high degree of quality control as compared to soil-lime stabilization.

3. Soil-lime Stabilization

⇰ Soil-lime is widely used either as modifier for clayey soil or as a binder.When clayey soil with high plasticity are treated with lime,the plasticity index is decreased and the soil becomes brittle and easy to be pulverized having less attraction with water.Lime also imparts some binding action.
In find grained soil lime imparts pozzolanic action which increases the strength.All these modifications are considered desirable for stabilization work.

⇰ Soil lime is quite suitable as sub-base course for high type of pavements with low traffic.But this method can not be used as surface course due to its poor resistance to abrasion and impact.This method is quite suitable in warm regions, but not very suitable under freezing temperature.

4. Soil-Bitumen Stabilization

⇰ The basic principles in bituminous stabilization are water proofing and binding.Generally both the binding and water proofing actions are provided to the soil by adding bituminous material.Most  commonly used bituminous materials are cutback and emulsion.

⇰ Bituminous stabilized layer can be used as a sub-base or base course of ordinary roads and even as a surface course for roads with low traffic in low rainfall region.

5. Chemical Stabilization

⇰ Granular soils lack stability when they are too dry.If their moisture content is stabilized by addition of some chemicals,then these soils can be used successfully.Chlorides of calcium and sodium are the most popular salts used for this purpose.A number of other chemicals/materials such as sodium silicate,lignin,resins,molasses etc,are used for chemical stabilization of soils.

Addition of chemicals with the soil helps to retain moisture and to impart some cohesion and thus retain the stability.These chemicals also reduce the dust nuisance in un-surfaced roads.