A Study on the Use of Crusher Dust and Pond Ash as Sub Grade and Fill Materials in Pavement

The construction of civil engineering structures such as roads, embankments, and ground reclamation require large quantities of natural soils and rock materials. However, the presence of plastic materials like silt and clay in these soils often leads to excessive deformations, compromising the durability and increasing maintenance costs. To address these challenges, this study explores the potential use of industrial wastes such as crusher dust and pond ash as geotechnical materials for road and embankment construction, specifically as sub-grade and fill materials. Crusher dust, a by-product of stone crushing plants, and pond ash, sourced from thermal power plant ash ponds, were combined in varying proportions to assess their suitability. The study evaluated the gradation, compaction, strength, and seepage characteristics of crusher dust and pond ash mixes. The results indicated that the mixes attained high densities (>1.6 g/cc), substantial California Bearing Ratio (CBR) values (>10%), high shear strength parameters (>36°), and maintained adequate permeability (k > 10^-3 cm/sec). Additionally, the mixes were found to be non-plastic and incompressible. Optimal performance was achieved with 30-40% pond ash added to crusher dust, making these mixes suitable for use as sub-grade and fill materials in line with MORTH specifications.