Light burned magnesia-silica fume stabilized dredged sediments: A multiscale study on performance enhancement and failure analysis

Dredged sediments can be stabilized to improve their engineering applicability. This study developed a low-carbon stabilization system (LBM-SF) utilizing medium-grade light-burned magnesia (LBM) and silica fume (SF) for treating dredged sediment. The failure behavior and microscopic mechanism of stabilized sediment were investigated through multiscale approach. By combining the unconfined compressive strength (UCS) test and digital image correlation (DIC) technology, the mechanical response and full-field strain distribution of the stabilized sediments were accurately captured throughout the failure process. XRD, TG/DTG, and SEM analyses further revealed the microstructural evolution mechanism regulating the macroscopic mechanical behavior. The results indicated that as the stabilizer (MS) dosage increased from 5 % to 20 %, the magnesium silicate hydrate (M-S-H) gel gradually evolved from a discrete petal-like structure to a continuous interwoven network, enhancing the strength and increasing the tendency toward brittle failure. DIC-based strain analysis showed that strain distribution transitioned from uniform to localized during compression, and the local strain concentration coefficient, c , increased from 1.5 to 3.5, whereas the concentration area ratio, γ , decreased from 0.64 to 0.28, highlighting the role of strain localization in driving failure. Ultimately, a constitutive model integrating DIC-quantified strain localization parameters was developed, which provides a data-driven approach to accurately characterize and predict the failure process, advancing the methodological framework for failure analysis of similar cemented geomaterials.