Sustainable Utilization of Dredged Sediments and Water Treatment Sludges as Construction Materials through Combined Dewatering and Cement Stabilization Techniques

This study investigates the sustainable use of seabed dredged slud‬ge and water treatment sludges as construction materials using combined dewatering and cement stabilization techniques. Dredged sediments and water treatment sludges, typically considered waste, were evaluated for their suitability in construction through a series of dewatering and stabilization processes. Dewatering significantly reduced initial moisture content, while cement stabilization improved mechanical properties, including strength and stiffness. Unconfined compressive strength (UCS), shear modulus, and microstructural changes were evaluated using various analytical techniques, including unconfined compression testing, X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDX). The results show a direct correlation between reduced water-cement ratios and increased UCS, confirming the potential of treated sludge as a sub-base layer for roads and landfill liners. Chemical analysis revealed the formation of calcium silicate hydrate (CSH) and ettringite, which are critical for strength enhancement. This approach not only mitigates environmental issues associated with sludge disposal, but also supports sustainable construction practices by reusing waste materials. The study concludes that cement-stabilized dredged sediments and water treatment sludges provide an environmentally friendly and effective alternative for use in civil engineering projects.