Sustainable use of Fly Ash and used Face Masks for the Improvement of Engineering Characteristics of Expansive Clays.

The paper explores challenges arising from the existence of expansive clay soils, renowned for causing structural damage and exhibiting detrimental environmental effects. Implementing a novel approach, this study introduces the use of fly ash (Class F) and shredded face masks (FMs) to enhance soil properties. Fly ash (FA), known for its pozzolanic properties, is combined with shredded waste FMs to reinforce the soil. Remolded specimens underwent comprehensive laboratory testing, including Unconfined Compressive Strength (UCS), California Bearing Ratio (CBR), Swell Test, Consolidation Test, and Triaxial Test. The optimal blend identified as 0.9% FMs + 20% FA achieves an optimal equilibrium of strength, stability, and reduction in swelling. The UCS exhibited an increase with the addition of FA, and this improvement was further enhanced with the inclusion of 0.9% FMs, surpassing the specified subgrade CBR values. The percentage of swell exhibited a notable decrease from 5.9% to 1.8% with the incorporation of FA + FMs. This sustainable approach aims to conserve valuable resources and mitigate challenges associated with waste disposal along with the economic benefits to contribute to achieve UN SDGs 2030. [ABSTRACT FROM AUTHOR]