Suitability of Fly Ash-Cement Kiln Dust Columns for Stabilizing Expansive (Black Cotton) Soils

Abstract

The paper focuses on the potential use of industrial wastes, which are fly ash (FA) and cement kiln dust (CKD), to stabilize expansive soils like black cotton (BC) soil for construction purposes. Although many soil stabilization methods exist, the placement of columns consisting of industrial wastes has yet to be tested. Knowing the pozzolanic action and mechanism between the waste product and the soil, this method of placing the industrial waste as a remedy should be trialled. Therefore, this paper proposes and investigates the placement of FA-CKD columns into the soil via a series of laboratory experiments using myriad mixtures and combinations of placement of such columns. The effect of molding water content and curing time on the BC soil’s consolidation and strength behavior was also assessed here. Through the experiments, it is found that the optimum mixture of FA-CKD for the columns is at 90–10%, respectively. This column mixture has been evidenced to improve the unconfined compressive strength of the soil significantly, where its performance improves with curing time. The highest strength improvement can be found at optimum moisture content, followed by wet of optimum and dry of optimum, respectively. By placing the columns in the soil with 4.5D spacing, better consolidation behavior with a reduced swelling potential of BC soil can be found. Based on the above findings, using FA-CKD columns can improve the BC soil’s engineering behavior, contributing to waste-to-wealth and sustainable soil stabilization approaches.

Received: 28 July 2023 | Revised: 9 August 2023 | Accepted: 19 October 2023

Conflicts of Interest

The authors declare that they have no conflicts of interest to this work.

Data Availability Statement

Data sharing is not applicable to this article as no new data were created or analyzed in this study.

Author Contribution Statement

B. S. Pankaja: Conceptualization, Methodology, Validation, Formal analysis, Investigation, Writing - original draft; N. H. Ranjita: Methodology, Validation, Formal analysis, Investigation, Writing - original draft; H. N. Ramesh: Conceptualization, Formal analysis, Investigation, Writing - review & editing, Visualization, Supervision; Jun Cheng Kho: Formal analysis, Investigation, Writing - review & editing; Mavinakere Eshwaraiah Raghunandan: Conceptualization, Formal analysis, Investigation, Writing - review & editing, Visualization, Supervision.