Steel slag was utilized in both the Pavement Quality Concrete (PQC) layer and the stabilized base, offering a sustainable alternative to conventional materials. To determine the optimal mix, extensive site and lab trials were conducted, and the final design was approved by the competent authority.
The process began with a thorough assessment of the existing road, considering traffic, soil, climate, and material properties. The subgrade was leveled, cleaned, and compacted to ensure a stable base. As per IRC:120-2015, the stabilized layer was prepared using 7% OPC and 2% NovoCrete (by weight of cement), with steel slag as coarse aggregate and slag dust as fine aggregate. Mixing was done in situ, ensuring proper gradation per MoRTH Table 400-4.
Compaction was carried out using an 8–10 ton vibratory roller, followed by quality control tests including UCS (min 4.75 MPa), flexural strength (≥20% of UCS), durability (≥80% retained strength), and gradation checks.
A 150 mm PQC layer was laid over the stabilized base with 1.2 m × 1.2 m joints. A 150-micron polythene sheet was placed as a bond breaker. Curing was done using moisture-retaining covers and water spraying for at least 7 days. This method provided a durable, eco-friendly pavement structure with improved strength and performance.