Al-Qadisiyah Journal for Engineering Sciences

Effect of ground granulated blast furnace slag–stabilized bentonite soils on flexible pavement design and cost analysis

Document Type : Research Paper

Authors

Bahadır Karabaş 1
Ali Ulvi Uzer 2

1 İnönü University, Department of Civil Engineering, İnönü University, Malatya, Turkey.

2 Kayseri University, Department of Construction, Vocational School of Technical Sciences, Kayseri University, Kayseri, Turkey.

https://doi.org/10.30772/qjes.2026.169263.1896
Abstract
In this study, the effects of ground granulated blast furnace slag (GGBFS) stabilization of subgrade soil on flexible pavement layer thicknesses and initial construction costs were investigated. For this purpose, Proctor compaction tests were conducted on bentonite (BT) soil samples prepared by adding GGBFS at rates of 5%, 10%, 15%, and 20% by weight. Following these tests, unconfined compressive strength specimens were prepared and tested after curing periods of 3 and 7 days. The results indicated that the highest compressive strength was obtained in mixtures containing 15% GGBFS. In addition, untreated soil and soil samples stabilized with 15% GGBFS were subjected to the California Bearing Ratio (CBR) test after 3 and 7 days of curing. It was determined that the CBR values of the samples containing 15% GGBFS increased by 2.09 and 2.85 times, respectively. Using the CBR values obtained, pavement layer thicknesses were calculated based on the AASHTO 1993 flexible pavement design guidelines, and cost analyses were performed. The results showed that stabilization with 15% GGBFS reduced the initial construction costs by 23.03%.

Keywords

Ground granulated blast furnace slag
Bentonite clay
Soil stabilization
Flexible pavement design
Transportation geotechnics
Crossmark
Subjects
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Al-Qadisiyah Journal for Engineering Sciences
Volume 19, Issue 2
Summer 2026
Pages 195-202

  • Receive Date 06 February 2026
  • Revise Date 25 February 2026
  • Accept Date 26 February 2026

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