Engineering properties and mechanistic insights of fluid fill material derived from multi-source solid wastes

Area of Science:

• Environmental Engineering
• Materials Science
• Sustainable Construction

Background:

• Synergistic utilization of solid waste is a key environmental engineering challenge.
• Multi-source solid wastes like DWTR, MSS, RFA, and mud possess diverse physicochemical properties.
• Developing effective methods for solid waste valorization is crucial for resource management.

Purpose of the Study:

• To propose and investigate a novel solid waste-based fluid-filled material (FFM).
• To address the challenges posed by physicochemical differences in multi-source solid wastes.
• To optimize FFM properties for excellent mechanical performance and durability.

Main Methods:

• Precisely controlling fluidity, water-to-solid ratio, and wet density of FFM.
• Systematic optimization of mix ratios, including Lime, DWTR, MSS, RFA, mud, and LCCCM.
• Utilizing micro-characterization techniques such as SEM and XRD for structural analysis.

Main Results:

• FFM with controlled fluidity (160-200 mm), water-to-solid ratio (0.52-0.87), and wet density (1.47-1.68 g/cm³).
• Achieved 7-day and 28-day compressive strengths of 0.20-1.20 MPa and 0.40-1.40 MPa, respectively.
• Optimal mix ratio (1:5:5:10:67:12) yielded 0.70 MPa 28-day compressive strength, meeting engineering standards.

Conclusions:

• The developed FFM exhibits excellent mechanical properties and durability.
• Increasing LCCCM and RFA proportions enhances mechanical properties.
• Microstructural analysis confirms dense packing and effective pore filling, guiding low-carbon flowable solidified soil development.