Article Sidebar

Submitted
3 August 2026
Accepted
8 August 2026
Published
18 September 2026
Download
PDF
Statistic
Read Counter : 3 Download : 3

Main Article Content

Abstract

Peat soil is characterized by high water content and low bearing capacity, making it unsuitable for use as a road subgrade without stabilization treatment. This study aims to analyze the physical characteristics of natural peat soil from Kenan Sandan, East Kotawaringin, and evaluate the California Bearing Ratio (CBR) values after stabilization using lime and fly ash. Laboratory tests included physical properties, Modified Proctor compaction, and soaked CBR tests with lime variations of 10%, 15%, 20%, and combinations of lime (15% and 20%) with 10% fly ash at 1 and 3-day curing periods. The results showed that the peat soil has a moisture content of 97.54%, specific gravity (Gs) of 2.22, liquid limit (LL) of 69.25%, plasticity index (PI) of 38.61%, and pH of 5, classifying it into the A-8 group (organic soil) based on AASHTO M145. The 3-day soaked CBR of natural soil was only 2.26%, failing to meet the minimum 6% requirement of MDPJ 2024. The 10% lime addition was ineffective, yielding a CBR of only 2.44%. However, 15% and 20% lime additions significantly increased CBR values to 20.22% and 22.59%, respectively. The highest performance was achieved by the 20% lime + 10% fly ash combination with a CBR of 27.04% at 3-day curing. Pavement thickness analysis indicated that stabilization with 15% lime or more can reduce the required Class C Aggregate Base (LFA) thickness to 150 mm. In conclusion, the combination of 20% lime and 10% fly ash is the most effective mixture for improving the bearing capacity of peat soil for road subgrades.

Keywords

CBR fly ash lime peat soil stabilization subgrade

Article Details

References

  1. Badan Pusat Statistik Kabupaten Kotawaringin Timur, Kabupaten Kotawaringin Timur Dalam Angka 2025. Sampit: BPS Kabupaten Kotawaringin Timur, 2025.
  2. A. Ahmad et al., "Physio-chemical properties, consolidation, and stabilization of tropical peat soil using traditional soil additives—A state of the art literature review," KSCE Journal of Civil Engineering, vol. 25, no. 10, pp. 3662-3678, 2021.
  3. K. C. Onyelowe et al., "Estimating the strength of soil stabilized with cement and lime at optimal compaction using ensemble-based multiple machine learning," Scientific Reports, vol. 14, no. 1, p. 15308, 2024.
  4. R. Renjith et al., "Optimization of fly ash based soil stabilization using secondary admixtures for sustainable road construction," Journal of Cleaner Production, vol. 294, p. 126264, 2021.
  5. V.-L. Nguyen, V. T.-A. Phan, and H.-B. Tran, "Potential of fly ash, cement, and enzyme stabilized soil for road construction," Transportation Infrastructure Geotechnology, vol. 10, no. 6, pp. 1050-1071, 2023.
  6. Direktorat Jenderal Bina Marga, Manual Desain Perkerasan Jalan No. 03/M/BM/2024. Jakarta: Kementerian Pekerjaan Umum dan Perumahan Rakyat, 2024.
  7. American Association of State Highway and Transportation Officials, Standard Specification for Classification of Soils and Soil-Aggregate Mixtures for Highway Construction Purposes, 2021.
  8. B. M. Das, Advanced Soil Mechanics. Boca Raton: CRC Press, 2019.
  9. Y. Yudhyantoro, "Pengaruh Penambahan Kapur terhadap Kepadatan dan Nilai CBR Tanah Gambut Abu Tinggi," Jurnal Teknik Sipil, vol. 2, no. 2, pp. 137-146, 2013.
  10. A. M. Abdelbaset et al., "Mechanical properties stabilization of low plasticity Kaolin soil using fly ash and hydrated lime," Case Studies in Construction Materials, vol. 21, p. e03662, 2024.
  11. ASTM International, Standard Test Method for California Bearing Ratio (CBR) of Laboratory-Compacted Soils, 2021.
  12. E. O. Tastan et al., "Stabilization of Organic Soils with Fly Ash," Journal of Geotechnical and Geoenvironmental Engineering, vol. 137, no. 9, pp. 819-833, 2011.
  13. T. E. Wulandari and R. Surbakti, "Stabilisasi Tanah Gambut Menggunakan Kapur dengan Pengujian CBR," Agregat: Jurnal Ilmiah Teknik Sipil, vol. 3, no. 2, pp. 96-103, 2023.
  14. M. K. Muwaffa, "Pengaruh Campuran Kapur terhadap Kepadatan Tanah Lempung dengan Pengujian CBR," Jurnal Tugas Akhir Teknik Sipil, vol. 5, no. 2, pp. 32-41, 2021.
  15. E. Mina, R. I. Kusuma, and Z. I. Sausan, "Pemanfaatan Semen Slag Sebagai Campuran Stabilisasi Tanah dan Pengaruhnya terhadap Nilai CBR Terendam (Soaked California Bearing Ratio)," Jurnal Teknik Sipil, vol. 28, no. 3, 2021.
  16. T. Sambre, M. Endait, and S. Patil, "Sustainable soil stabilization of expansive soil subgrades through lime-fly ash admixture," Discover Civil Engineering, 2024.
  17. D. O. Dwina et al., "Stabilisasi Tanah Gambut Dengan Penambahan Kapur dan Fly Ash Sisa Pembakaran Cangkang Sawit Sebagai Subgrade Jalan," Jurnal Fondasi, vol. 10, no. 1, 2021.
  18. N. Mohd Zambri and Z. Md. Ghazaly, "Peat soil stabilization using lime and cement," in E3S Web of Conferences, 2018.
  19. B. B. K. Huat et al., Geotechnics of Organic Soils and Peat, 1st ed. Boca Raton, Florida: CRC Press, 2014.
  20. M. S. Sutarno and H. M. Mohamad, "Peat soil compaction characteristic and physicochemical changes treated with Eco-Processed Pozzolan (EPP)," Civil Engineering Journal, vol. 9, no. 1, pp. 86-103, 2023.
  21. M. T. Mohamad Zulkifley et al., "Definitions and Engineering Classifications of Tropical Lowland Peats," Bulletin of Engineering Geology and the Environment, vol. 72, no. 3-4, pp. 547-553, 2013.
  22. P. Utkarsh, "Enhancing the properties of swelling soils with lime, fly, ash, and expanded polystyrene—A Review," Heliyon, vol. 10, p. e32908, 2024.