Development of a Material Based on Shale and Blast Furnace Slag for Use in Road Construction

Abstract:

This research investigates the progressive substitution of natural aggregates, conventionally used in road construction, with alternative materials derived from industrial co-products. Specifically, the study focuses on developing an innovative material that combines shale aggregates and blast furnace slag for road construction applications. The experimental procedure involved preparing various mixtures with slag content ranging from 10% to 50%, followed by comprehensive laboratory characterization through standardized mechanical and road performance tests. The results demonstrate that these composite materials exhibit highly promising characteristics. Mixtures containing 30–50% slag meet all current standard requirements, showing particularly excellent performance in bearing capacity (with CBR values reaching 62.15 for the 50% slag mixtures), while maintaining outstanding water stability (with variations of less than 4% after immersion).These mechanical properties, combined with consistent dry density values above 2.1 g/cm³ and a maximum internal friction angle of 43.53°, make these materials especially suitable for pavement layers. Beyond their technical performance, the shale–slag composites offer a sustainable solution with dual benefits: they significantly reduce pressure on depleting alluvial deposits while effectively valorizing abundant industrial by-products.Based in these findings, it is strongly recommended that such materials be integrated into conventional pavement construction, particularly for low to medium traffic. This circular economy approach therefore represents both a high-performance and environmentally responsible alternative to traditional materials.

• Periodical: International Journal of Engineering Research in Africa (Volume 77)
• Pages: 51-66
• DOI: https://doi.org/10.4028/p-z9AdAv
• Online since: December 2025
• Authors: Idir Amara*, Omar Boudlal, Ahmed Benamar, Mohamed Tahar Ammami, Abdelkader Iddir, Yahya Messani
• Keywords: Blast Furnace Slag, Environment, Road Construction, Shale, Valorization

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