Amending excavated soft marine clay with fine incineration bottom ash as a fill material for construction of transportation infrastructure

• Main Authors: Sun, Xinlei, Yi, Yaolin
• Other Authors: School of Civil and Environmental Engineering
• Format: Article
• Language: English
• Published: 2022
• Subjects: Engineering::Civil engineering; Transportation Infrastructure; Marine Clay
• Online Access: https://hdl.handle.net/10356/162333
• Institution: Nanyang Technological University

The fast development of transportation infrastructure has increased the consumption of construction materials, resulting in overexploitation and depletion of natural aggregates. Meanwhile, the increasing amount of solid wastes is another rising problem due to the growing economy and rapid urbanization. Instead of using natural aggregates as fill materials for transportation infrastructure, the solid wastes can be treated and reused as alternatives, which can reduce the reliance on natural resources and landfill. Therefore, in this study, the mixture of two solid wastes, i.e., excavated soft marine clay (MC) and fine incineration bottom ash (IBA) of municipal solid waste, was studied as a fill material for construction of transportation infrastructure. Mixtures of IBA and MC (IBA-MC) with different IBA/MC mass ratios (0/10, 1/9, 2/8, 3/7, 4/6, 5/5, 6/4, and 10/0) were prepared. The Atterberg limits, compactability, unconfined compressive strength (UCS), leaching of heavy metals, mineralogy, and microstructure of IBA-MC were studied. The results showed that, as the content of IBA/MC ratio increased, the water content, liquid limit, and plastic limit of IBA-MC decreased, changing it from plastic paste to semi-solid/solid granular material. The compactability and UCS of IBA-MC were improved when the IBA/MC ratio increased from 1/9 to 5/5. For the IBA-MC with IBA/MC ratio of 1/9 to 5/5, the leaching of heavy metals satisfied the criteria for construction material. In summary, IBA improved the compactability and strength of MC, while MC reduced the leaching of heavy metals from IBA, and IBA-MC with proper ratio could be compacted as a fill material for construction of transportation infrastructure.