Impact of sandstone slurry waste with calcium carbonate nanoparticles on geotechnical properties of clayey soil subgrade

The sustainable geotechnical approach for addressing the challenges associated with clayey soils at construction sites involves the modification of these soils’ mechanical and chemical characteristics using soil enhancement methods. The present study investigates the coupling effect of sandstone slu...

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Bibliographic Details
Main Authors: Amrit Singh Shekhawat, Suresh Kumar Tiwari
Format: Article
Language:English
Published: Elsevier 2025-08-01
Series:Journal of Rock Mechanics and Geotechnical Engineering
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Online Access:http://www.sciencedirect.com/science/article/pii/S1674775525001805
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Summary:The sustainable geotechnical approach for addressing the challenges associated with clayey soils at construction sites involves the modification of these soils’ mechanical and chemical characteristics using soil enhancement methods. The present study investigates the coupling effect of sandstone slurry waste (SSW) and calcium carbonate nanoparticle (CCN) as potential stabilizers to enhance the characteristics of clayey soil. A comprehensive investigation was conducted using compaction tests, plasticity index (PI) tests, California bearing ratio (CBR) tests, unconfined compressive strength (UCS) tests, and microstructural analyses of clayey soil, SSW and SSW-CCN-treated clay samples containing 5%, 10%, 15%, 20%, 25%, 30%, and 35% SSW and 0.3%, 0.6%, 0.9%, 1.2%, and 1.5% CCN mixed with clayey soil in different combinations of clay, SSW, and CCN. The findings reveal that incorporating 25% SSW with 0.9% CCN into clay soil results in an increase in the UCS from 132.2 kPa for untreated clayey soil without curing to 263 kPa after a 28-d curing period. Similarly, a rising trend in CBR results is observed up to 25% SSW addition in clay soil and up to 0.9% CCN addition in SSW-clay mixture. Initially, notable enhancements in UCS were attributed to a denser soil structure, followed by the formation of calcium–silicate–hydrate (CSH) gel, which intensified with prolonged curing. Gel patches were detected by scanning electron microscopy (SEM) in addition to particle aggregation. The results obtained from thermogravimetric analysis, Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) supported the presence of hydration products such as CSH. The experimental study indicates that SSW, in combination with CCN, offers a sustainable alternative to traditional soil stabilizers.
ISSN:1674-7755