碳化养护对矿渣-活性MgO-脱硫石膏固化疏浚淤泥耐久性能的影响OA

This study explores the influence of carbonation treatment on the durability of dredged sludge so-lidified with slag,active magnesium oxide(MgO)and desulphurization gypsum,under the conditions of wet-dry and freeze-thaw cycles.By establishing two distinct groups of control samples(namely,carbonised and non-carbonised)and integrating unconfined coressive strength testing with analytical techniques such as X-ray diffraction(XRD)and scanning electron microscopy(SEM),it systematically evaluates the effects of these two environmental cycles on both the macroscopic mechanical properties and the microscopic morphol-ogy of the solidified dredged sludge.The findings reveal that the mass variations of both carbonised and non-carbonised specimens exhibited relative stability throughout the wet-dry cycling process;conversely,during freeze-thaw cycling,both declined with the increase in cycle numbers.Furthermore,the strength of both specimen types demonstrated a consistent deterioration under the influence of both environmental cy-cling conditions.At an equivalent number of cycles,the residual strength of the carbonised samples was sig-nificantly greater than that of the non-carbonised counterparts,thereby indicating that carbonation treatment substantially enhances the material's capacity to withstand multifaceted environmental disturbances.Micro-structural analysis elucidated that with increasing cycles,the internal porosity of both sample types progres-sively escalated,leading to the formation of microcracks that markedly compromised the interparticle bond-ing forces.Consequently,this culminated in the deterioration of the material's mechanical properties and a concomitant reduction in the strength of the solidified sludge.