Soil Stabilization by Using Fly Ash and Rice Husk Ash

Abstract

A number of studies have been find out to investigate the effect of addition of waste materials on modifying the properties of soil. The present study shows the modification of soil properties by adding locally available materials such as rice husk ash and fly ash. The cost of stabilization may be reduced by replacing by a good proportion of stabilizing agent using rice husk ash. The soil used in the present study is clay with high compressibility, whichneeds to be strengthened to minimizevolume changes in the soil. The soil is stabilized by varying different percentages of rice husk ash and also fly ash. Observations are made for changes in compaction characteristics of the soil, unconfined compressive strength and California bearing ratio values of the soil. From the results, it is observed that the maximum dry density is increased with increase in percentages of rice husk ash, and the corresponding optimum moisture content is decreased and vice versa with the addition of fly ash to the soil. The optimum amount of rice husk ash and fly ash for improving the properties of the soil are discussed in detail. It can test by using some laboratory test like liquid limit , plastic limit and standard proctor test ( light compaction) , CBR test , Soil sample is mixing of fly ash as percentage of 5% , 10% , 15% , 20%and rice huskash of 10%, 15%, 20%, 25%, and the study of the work was to evaluate the effect of fly ash and rice husk ash to improve the performances of black cotton soil .

Introduction

The text discusses soil stabilization of Black Cotton soil using industrial waste materials like Fly Ash (FA) and Rice Husk Ash (RHA) to improve its engineering properties for construction.

Black Cotton soil is naturally fertile but highly problematic for construction because it is expansive, meaning it swells when wet and shrinks when dry, leading to low stability and poor load-bearing capacity. To overcome this, soil stabilization techniques are used to improve strength, durability, and volume stability.

The study focuses on using fly ash and rice husk ash as stabilizing agents, which help reduce swelling/shrinkage and improve properties such as bearing capacity, strength, and erosion resistance, while also lowering construction costs by utilizing waste materials.

The objectives include:

• Determining optimal moisture content (OMC) and maximum dry density (MDD)
• Improving strength of Black Cotton soil using FA and RHA
• Reducing shrink–swell behavior
• Recycling industrial waste for sustainable construction

The methodology involves collecting soil, mixing it with different percentages of FA and RHA, and conducting laboratory tests such as:

• Atterberg limits
• Standard Proctor test
• CBR (California Bearing Ratio)
• UCS (Unconfined Compressive Strength)

Key results show that:

• Increasing FA and RHA generally reduces MDD
• OMC increases with higher additive content
• CBR values significantly improve, indicating stronger soil and better load-bearing capacity

For example, CBR increases from about 2.26% (natural soil) to about 6.95% with higher FA and RHA combinations, showing clear improvement in strength.

Conclusion

The study on soil stabilization using fly ash and rice husk ash demonstrates that these waste materialscan effectively improve the engineering properties of weak soil. The addition of fly ash and rice husk ash reduced the plasticity characteristics of the soil and enhanced its compaction behavior by increasing the maximum dry density and reducing the optimum moisture content. The California Bearing Ratio (CBR) values also increased, indicating a significant improvement in the load-bearing capacity of the stabilized soil. The results show that the combined use of fly ash and rice husk ash provides better performance than untreated soil, making the soil more suitable for pavement subgrade and foundation applications. The optimum mix proportion produced the highest strength and stability, confirming that agricultural and industrial by-products can be used as cost-effective and environmentally friendly stabilizing agents.

References

[1] A. Kumar and D. Gupta, “Stabilization of clayey soil using fly ash and rice husk ash,” International Journal of Civil Engineering and Technology, vol. 8, no. 4, pp. 112–118, 2017. [2] M. Basha, R. Hashim, H. Mahmud, and A. Muntohar, “Stabilization of residual soil with rice husk ash and cement,” Construction and Building Materials, vol. 19, no. 6, pp. 448–453, 2005. [3] A. Muntohar and G. Hantoro, “Influence of rice husk ash and lime on engineering properties of a clayey subgrade,” Electronic Journal of Geotechnical Engineering, vol. 5, pp. 1–9, 2000. [4] S. Brooks, “Soil stabilization with fly ash and rice husk ash,” Journal of Materials in Civil Engineering, vol. 21, no. 4, pp. 123–130, 2009. [5] B. Prasad and K. Sharma, “Improvement in CBR value of expansive soil using industrial waste,” International Journal of Engineering Research and Applications, vol. 4, no. 8, pp. 95–101, 2014.

Copyright

Copyright © 2026 S. S. Balchatre, M. S. Howal, V. A. Mane, P. V. Kamble, K. W. Deshmukh, K. M. Dudhal, V. S. Bhakare. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.