ABSTRACT
Climate change is demanding cleaner industrial processes besides new techniques. Waste materials, such as water treatment sludge (WS), biomass ashes (BA), mining wastes (MW), and iron slags (IS) are largely produced around the world from varied industrial activities, they represent a hazardous when incorrectly disposed due to contamination potential of soils and waters, highlighting the necessity to find new applications for them. Geotechnical engineering has been a major area for employing new materials to improve current methods. Regarding geotechnical applications, soils can have problems like high volumetric variation, high plasticity, and elevated water absorption/retention capacity, causing fissures, cracks, and low mechanical strength. Several researches have exposed the above-mentioned residues’ value while improving overall aspects of the soils, successfully mitigating undesired characteristics, and making them feasible for geotechnical applications. Therefore, this paper aims to present and evaluate physical characteristics of residues alone, granular soils and mixtures of wastes-soils using varied introduction percentages of the residues into the soil, to assess their feasibility for improving the soil towards a geotechnical material for varied applications. Found results have shown all mixtures were considered as material for subgrade, according to AASHTO. Residues impacted the soil differently, WS, BA and MW led the granular soil to a finer material, while IS to a more granular material. Plasticity reduction up to 100% was achieved by WS, BA, and IS. Density was considerably increased by IS while MW sustained, and WS and BA have shown susceptibility into being light-weight materials.
