Waste to Resource: Enviro-Mechanical Suitability of MSW Incineration Bottom Ash in Flexible Pavements and Embankments

• Published in: International journal of geosynthetics and ground engineering 2024-04, Vol.10 (2), Article 17
• Main Authors: Bansal, Deepesh, Ramana, G. V., Datta, Manoj, Ramaiah, B. J.
• Format: Article
• Language: English
• Subjects: Abrasion; Aggregates; Bottom ash; Building Materials; Combustion; Cyclic loads; Durability; Embankments; Emissions; Engineering; Environmental Science and Engineering; Flexible pavements; Foundations; Geoengineering; Greenhouse gases; Hydraulics; Incineration; Leaching; Literature reviews; Original Paper; Roads & highways; Rural roads; Shear modulus; Shear strength; Stiffness; Subbases; Subgrades; Water absorption
• ISSN: 2199-9260; 2199-9279
• DOI: 10.1007/s40891-024-00528-4

The study investigated the potential of incineration bottom ash (IBA) as an alternative to natural aggregates in pavement subbase, subgrade, and embankments. An extensive literature review indicated that a comprehensive study characterizing bottom ash as fill material in pavements is missing. Additionally, IBA properties vary based on waste composition worldwide. In India, IBA is currently disposed in landfills because of a lack of technical exposure and this is the first detailed study of Indian IBA for use in pavements. Strength (bearing, shear), stiffness (secant, resilient, and shear modulus), durability, drainage, abrasion, and toughness characteristics of IBA collected from two incineration plants in India were evaluated. Furthermore, the study assessed the environmental suitability and economic feasibility of using IBA. The experimental results indicate that IBA offers high bearing (soaked CBR values of 40–48%) and shear strength (angle of shearing resistance of 46.3º–47.9º). The secant and resilient moduli of IBA are comparable to conventional material, suggesting its ability to withstand deformation under static and cyclic loading. Higher water absorption and abrasion values preclude its application in subbases of highways and urban roads. However, high strength, stiffness, permeability, durability, and leaching characteristics make IBA suitable for rural roads. IBA also fulfils the standard guidelines for use as fill material in road embankments and subgrades. Reusing IBA in constructing one km of flexible pavement conserves approximately 47 tons of natural aggregates and reduces cost by 20–40%. Additionally, it contributes to a 20% reduction in greenhouse gas emissions, making it a viable alternative to conventional materials.