Pavement Design and Cost Analysis of Mine Waste Stabilized Low Volume Roads

The extraction of minerals from the earth through mining has been one of the human activities since prehistoric times. These mining activities conducted through surface or sub-surface method leads to the generation of mine waste during the processing and extraction of minerals. The lack of storage space for mine waste and the environmental impact caused due to its storage has also been a major issue for the mining agencies. Black cotton soil (BC soil), on the other hand, is considered problematic due to its swell–shrink behavior during seasonal changes. The subgrade constructed on Black Cotton soil undergoes settlement and causes the pavement structure to fail. In the current study, efforts were made to resolve the issue of storage space of Mine Waste generated from mining activity to strengthen the weak subgrade soil such as BC soil. The engineering properties of Mine Waste stabilized soil samples were carried out and the optimum BC soil–Mine Waste mix was determined. Further, Granulated Blast Furnace Slag (GBFS) was blended with optimum BC soil–Mine Waste to enhance the engineering property. Pavement design was carried out using IITPAVE software. Cost Analysis was performed for the pavement section using the latest schedule of rates of the Dharwad region. Results indicated that 60% BC soil: 40% Mine Waste mix improved CBR strength from 2.3% to 5.6% and hence was considered as an optimum mix. The addition of 30% of GBFS to the optimum BC soil–Mine Waste mix further improved CBR strength to 10%. The same mix resulted in total cost savings of 41%.