Calcium carbide residue-based material for the stabilization of dredged sludge and its use in road subgrade construction

Abstract

Addressing the dual environmental challenges of dredged sludge disposal and the repurposing of industrial by-products, this study pioneers the application of Calcium Carbide Residue (CCR)-based materials for stabilizing dredged sludge in road subgrade construction. The proliferation of dredged sludge, characterized by high moisture content and pollutants, presents a significant environmental hazard, while CCR, a by-product of acetylene production, poses disposal and pollution challenges. This research endeavors to mitigate these issues by exploring the stabilization potential of CCR when mixed with dredged sludge, aiming to enhance the mechanical properties of materials used in road subgrade construction. Through comprehensive laboratory testing, including unconfined compressive strength assessments, scanning electron microscope analyses, and X-ray diffraction examinations, the study reveals the intricate physicochemical interactions between CCR and sludge. These interactions lead to notable improvements in material strength and moisture reduction, substantiating the efficacy of CCR-based binders in sludge stabilization. The CCR-based binder can make the strength of the stabilized sludge reach 215.4kPa and the water content drop to 32 %. Field tests conducted to assess real-world applicability confirm the laboratory results, demonstrating the treated material's suitability for road construction as per secondary road design criteria and its environmental safety. The research highlights the environmental and engineering benefits of using CCR-based materials for sludge stabilization, offering a sustainable solution to the challenges of dredged sludge management and industrial waste utilization. The findings represent a step forward in waste-to-resource conversion, promoting environmental sustainability in civil engineering practices.