Exploring sustainable construction: A case study on the potential of municipal solid waste incineration ashes as building materials in San Andres island

By 2024, San Andrés Island’s only sanitary landfill had reached full capacity, holding over 500,000 tons of waste. With limited storage options and an annual generation of 250,000 tons of municipal solid waste, incineration became a key waste management strategy. However, this process produces fly and bottom ash, which, despite reducing waste volume, still poses environmental risks and storage challenges due to its unique composition. This study explored alternatives for the beneficial reuse of bottom ash, including: 1) use as a supplementary cementitious material, 2) as an aggregate (sand) in conventional mortars, 3) as a constituent material for pavement (granular sub-base), and 4) in the production of prefabricated items such as pavers and urban furniture. The results indicated that the bottom ash does not exhibit pozzolanic activity per ASTM standards at 7 and 28 days. However, mortars and prefabricated concrete items incorporating bottom ash as aggregates showed compressive and flexural strength values greater than those set by the standards. Additionally, the ash met the performance specifications required for use in road construction materials, demonstrating its potential for use in different construction applications. These findings could potentially offer solutions to reduce the stockpiling of incineration by-products in San Andrés Island, minimize environmental risks associated with their storage, and contribute to a circular green economy by transforming waste into valuable resources for sustainable development. • Municipal Solid Waste Incineration Ashes are repurposed as subbase for pavements and aggregates for cementitious mixtures. • When stabilized through different methods, these residues pose no environmental risks in their use as construction materials. • Additional treatments compared to conventional materials are necessary for using these ashes as construction materials.