Select geotechnical properties of a lime stabilized expansive soil amended with bagasse ash and coconut shell powder

Abstract

Lime stabilization has been and still is one of the most preferred methods for stabilization of expansive soils. However, in the recent times, utilization of solid waste materials in soil stabilization has gained prominence as an effective means to manage wastes generated from various sources. In this work, an attempt has been made to utilize waste materials from two sources as auxiliary additives to lime in the stabilization of an expansive soil. Bagasse ash (BA), a waste by-product from the sugar industry and Coconut shell powder (CSP), a processed waste obtained from left over coconut shells of oil extraction industry were used as auxiliary additives. An expansive soil obtained from a local field was subjected to chemical, mineral, microstructural and geotechnical characterization in the laboratory and stabilized using 3% lime. The waste materials were subjected to chemical, mineral and microstructural characterization. The stabilization process was amended with four different contents viz. 0.25%, 0.5%, 1% and 2% of BA and CSP separately and the effect of the amendment was studied on the unconfined compressive strength (UCS), plasticity, swell-shrink and microstructural characteristics of the expansive soil. The results of the study indicated that BA amendment of lime stabilization performed better than CSP in improving the UCS, plasticity, swell-shrink and microstructure of the lime stabilized expansive soil.

Blending Lime with Sugarcane Bagasse Ash for Stabilizing Expansive Clay Soils in Subgrade

“…This occurs through speeding up the stabilizing process by quickening the breakdown of the structure plus the creation of new reaction products [1,15,42]. The microstructural analysis as reported previously also confirms this role of SCBA [15,31,43]. In these findings, this SCBA stabilization process enhancement was also indicated by a reduction of unreacted soil zones.…”

“…The chemical analysis showed that the SCBA contained very high components of amorphous silica at 63.59% and alumina at 5.66%, which are needed to facilitate the chemical reaction with calcium oxide from hydrated lime to facilitate a pozzolanic reaction, as identified by [33]. In line with that, hydrated lime also contains the essential ingredient CaO, which is highly needed to produce hydrates in the pozzolanic reaction [31].…”

“…Chemical analysis of the sugarcane bagasse ash was performed using a X-ray fluorescence spectrometer machine (XRF) from the X-5000 series at the College of Geology and Petroleum Studies Laboratory of Makerere University. This characterization was done as adopted in [31]. The results were as tabulated in Table 1.…”

“…The effect on the plasticity can be attributed to the replacement of much of the plastic particles in the clay with less plastic ones in the SCBA-lime mixture and, again, the calcium for iron exchange and hence flocculation-aggregation occurs [12,31,40]. Therefore, it can be stated that the SCBA richness in SiO2 facilitated pozzolanic reactions, hence the expansive soil structure change and the resultant plasticity alteration [15].…”

Utilization of Sugarcane Bagasse Ash from Power Co-generation Boilers as a Supplementary Cementitious Material

“…However, given that the chemical contents do vary greatly due to difference in environmental conditions. For example, a combination of the three elements contributing to the pozzolanic reaction of Fe2O; Al2O3, and SiO2 can vary so widely, Srinivasan and Sathiya (2010) 90.5% for the three; 95.29% in Loganayagan et al, (2020); 73% in Venkatesh and Pradeepa (2019); 70.48% Anupam et al (2013) and as low as 40.66% (James and Pandian (2018), and 71.22% (Barasa et al, (2015) done in Kenya. Therefore, since there a paucity of literature in the East African region, more studies are still needed.…”