Study on the Rheological Properties and Microstructural Evolution Mechanism of Multicomponent Solid Waste...

Area of Science:

• Materials Science
• Geotechnical Engineering
• Waste Management

Background:

• Traditional cement-based slurries pose environmental and cost challenges.
• Utilizing solid waste in filling slurries is crucial for sustainable construction.
• Iron tailings and industrial by-products offer potential as alternative construction materials.

Purpose of the Study:

• To enhance the rheological properties and engineering applicability of fully solid waste filling slurry.
• To investigate the synergistic effects of steel slag and desulfurization ash on slurry performance.
• To develop a cost-effective and sustainable alternative to cement-based slurries.

Main Methods:

• Central composite design experiment to optimize steel slag (10-30%) and desulfurization ash (10-30%) content.
• Rheological property measurement using expansion tests and L-tube models (Bingham fluid model).
• Micro-mechanistic analysis including isothermal calorimetry and microscopic image processing.

Main Results:

• Optimal mix (20% steel slag, 20% desulfurization ash) achieved 5.90 MPa uniaxial compressive strength at 28 days.
• Yield stress and plastic viscosity optimized to 146.71 Pa and 3.04 Pa·s, respectively.
• Desulfurization ash reduced yield stress by 38% and increased fractal dimension to 1.906; steel slag enhanced stability and regulated hydration.

Conclusions:

• The optimized solid waste filling slurry demonstrates excellent rheological and mechanical properties.
• Synergistic use of steel slag and desulfurization ash effectively modifies slurry performance.
• This approach offers significant cost savings (up to 65%) and environmental benefits compared to cement-based systems.