The effect of lime pile parameters on the improvement of the swelling potential of expansive clay


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Çokça E., Özkan İ.

ARABIAN JOURNAL OF GEOSCIENCES, pp.1-13, 2022 (Peer-Reviewed Journal)

  • Publication Type: Article / Article
  • Publication Date: 2022
  • Doi Number: 10.1007/s12517-022-10807-x
  • Journal Name: ARABIAN JOURNAL OF GEOSCIENCES
  • Journal Indexes: Science Citation Index Expanded, Scopus, Aquatic Science & Fisheries Abstracts (ASFA), Geobase, INSPEC
  • Page Numbers: pp.1-13

Abstract

Expansive clay found especially in the semi-arid or arid regions of the world is a problematic soil that causes much damage to the lightweight structures built by civil engineers. The Lime pile technique is one of the improvement techniques applied for the stabilization of the expansive clay subgrade layer of highway constructions. The achievement of this technique depends on lime diffusion into expansive clay which is affected by some parameters related to the lime pile such as the height of the lime pile, the surrounding area of all lime piles, area ratio, total lime pile volume, water percentages of the water-lime mixture, lignosulphonate added to the water-lime mixture and curing time. In this study, the heights of the lime piles are equal to 2/3 of active zone depth or full height of active zone depth, two different lime pile diameters which are 4.5 mm and 6.5 mm are selected and three different water percentages of lime-water mixtures are prepared as 0%, 18%, and 30%, respectively. Finally, sodium lignosulphonate (NaLS) and calcium lignosulphonate (CaLS) are added separately to the lime-water mixture. Thus, the lime pile parameters mentioned above have been investigated in this study and the most effective lime pile installation model has been developed. The Lime pile technique with NaLS and CaLS addition prevented the formation of ettringite minerals. The swell potentials of lime pile-treated soil with NaLS and CaLS addition were much lower than the swell potential of lime pile-treated soil. Calcium lignosulphonate is more effective than sodium lignosulphonate as calcium ions are more prone to ion exchange than sodium ions. The best lime pile model is obtained when the heights of the lime piles are equal to the full height of active zone depth and when the water content of the water- lime- CaLS mixture is equal to 30%.