Soil stabilization by using bio-polymers

Published on 03 Jul 2021. Written by Akshay

Just like other construction materials soil has its own scientific analysis with regards to its abilities in dealing with forces. Soil is one of the most complex materials in civil engineering to the point that when it comes to the factor of safety in designing structures like foundations, or soil-based constructions.

We know that when it comes to designing in soil, the uncertainty is very high because it involves many risks and various factors to be considered in the soil analysis because even a small mistake results in higher design values and it leads to failure of the structure.

In this project, the attempt is to use biopolymers to improve the soil properties. The biopolymers used here are Xanthan gum and guar gum which are friendly to the environment and used as additives for soil stabilization

Study on expansive soil

Expansive clay: It is a clay soil that shows large volume changes that directly depends on the change in water content. The more the amount of expansive mineral in the soil leads to more cracks in dry seasons. This behavior is attributed to the presence of a clay mineral called montmorillonite.

Expansive soil covers more than twenty percentage geographical area of India

Soil stabilization

Soil stabilization is a method of changing the properties of natural soil such that it satisfies the design requirements.

Mainly our project is to strengthen the expansive soil using stabilizer which is environmental friendly and easily available.

Principles of soil stabilization

Evaluate the properties of a given soil
Deciding the effective and economical method of stabilization.
To design the stabilized soil mix with values of stability and durability.
Following the procedure adequately and compacting the stabilized layers.

Methods of soil stabilization

Cement stabilization
Lime stabilization
Bitumen stabilization
Chemical stabilization

Needs and Advantages

Stabilization improves the workability and the durability of the soil.
Soil stabilization is also used to prevent erosion of soil or dust formation, which is helpful in dry and arid weather.

Various materials used for soil stabilization

Geopolymers
Nylon fibers
Bitumen
Biopolymers

Bio-polymers

Xanthan gum (C₃₅H₄₉O₂₉)
A polysaccharide that has many industrial uses, including as a common food additive
It is produced by the fermentation of glucose and sucrose
It is prepared by the bacteria being inoculated into a sterile aqueous solution of carbohydrates, a source of nitrogen,di-potassium phosphate and some trace elements
Xanthan gum solutions are non-Newtonian and highly pseudoplastic
Xanthan gum is also stable over a wide range of temperatures
These are alkaline and salty mixtures.

2) Guar Gum

These have thickened and stabilizing properties
India produces about 2.5 - 3 million tons of guar annually, making it the largest producer
Guar gum is more soluble than locust bean gum due to its extra galactose branch points
Guar gum retards ice crystal growth by slowing mass transfer across the solid/liquid interface

Results

Xanthan gum showed a 631% increase in strength at an optimum value of 1% at 28days. This increase is due to polysaccharides
Gaur gum showed a 101% increase in strength at an optimum value of 1.5% at 0 days
The Mixture of Xanthan and Guar gum showed a 303% increase in strength at an optimum value of 1% at 28 days

Conclusion

Xanthan gum is preferable when compared to the other two because it forms the hydrogen bonds which is considered as the strongest bond that may be the reason for binding the soil particles by producing cementious property.

Kit required to develop Soil stabilization by using bio-polymers:

Technologies you will learn by working on Soil stabilization by using bio-polymers:

Soil stabilization

Soil stabilization by using bio-polymers

Study on expansive soil

Soil stabilization

Principles of soil stabilization

Any Questions?

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