The rapid depletion of natural aggregate resources and the increasing generation of industrial waste materials have become major challenges in the road construction sector. Large quantities of aggregates are required for pavement construction, resulting in excessive quarrying, crushing, and transportation activities, which consume significant energy and harm the environment. At the same time, industrial by-products such as steel slag and locally available marginal materials like moorum create disposal and environmental problems. Therefore, the use of such alternative materials in pavement construction is an important step toward sustainable transportation infrastructure. This study focuses on the mechanical characterization of cement stabilized moorum-steel slag systems for use in pavement base and sub-base layers. Steel slag obtained from the steel industry and locally available hard moorum were used as alternative aggregate materials. The study evaluates their suitability through various laboratory investigations related to physical, mechanical, mineralogical, and environmental properties. Different tests were conducted to determine gradation, specific gravity, water absorption, compaction characteristics, California Bearing Ratio (CBR) and Unconfined Compressive Strength (UCS). Advanced analytical techniques such as X-Ray Fluorescence (XRF), X-Ray Diffraction (XRD) and Toxicity Characteristic Leaching Procedure (TCLP) were also performed to identify the chemical composition, mineral phases and environmental safety of steel slag. Conventional crushed aggregates were blended with slag and moorum to satisfy the grading requirements specified by the Ministry of Road Transport and Highways (MoRTH). The experimental results indicated that steel slag possesses excellent engineering properties and can be effectively utilized up to 80% in pavement sub-base applications. Hard moorum was found suitable up to 50% when stabilized with cement. The cement stabilized moorum-steel slag mixtures showed satisfactory strength and durability characteristics for pavement construction. The toxicity analysis further confirmed that the concentration of heavy metals in slag and its leachate water remained within permissible environmental limits.

Keywords: Steel Slag, Hard Moorum, Cement Stabilization, Mechanical Characterization, Sustainable Transportation Infrastructure, XRD Analysis, Unconfined Compressive Strength.