Alkali-Activated Dredged-Sediment-Based Fluidized Solidified Soil: Early-Age Engineering Performance and Microstructural Mechanisms
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View abstract on PubMed
Summary
This summary is machine-generated.This study optimized fluidized solidified soil (FSS) for marine pile scour repair by adding silica fume (SF). An 8% SF addition with a 0.525 water-solid ratio (WSR) balances workability and early strength for effective remediation.
Area Of Science
- Geotechnical Engineering
- Marine Civil Engineering
- Materials Science
Background
- Fluidized solidified soil (FSS) shows promise for marine pile scour remediation.
- Current limitations include a narrow construction window and susceptibility to erosion before curing.
Purpose Of The Study
- To systematically evaluate FSS formulations using dredged sediment, varying silica fume (SF) content (0-12%), and quicklime activation.
- To determine optimal mix designs balancing flowability and early-age mechanical properties for marine pile scour repair.
Main Methods
- Experimental assessments included flowability, unconfined compressive strength (UCS), and direct shear tests.
- Microstructural analysis utilized X-ray diffraction (XRD) and scanning electron microscopy (SEM).
- Evaluated three water-solid ratios (WSR: 0.525, 0.55, 0.575) and four SF replacement levels (0%, 4%, 8%, 12%).
Main Results
- Silica fume (SF) substitution extended the operational period by mitigating flowability loss.
- Optimal performance was observed at 8% SF replacement and WSR = 0.55, yielding a 22.78% increase in 3-day UCS and improved cohesion and friction angle at 7 days.
- Microstructural analysis confirmed SF's pozzolanic reaction producing C-S-H gel, but levels above 8% led to unreacted particles disrupting the matrix.
Conclusions
- An 8% SF substitution and WSR of 0.525 represent the optimal mix for marine pile scour repair.
- Achieving a balance between flowability and early-age strength is crucial for stable FSS remediation.
- The findings provide critical insights for developing durable and effective marine infrastructure repair solutions.
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