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The process of filling self-compacting cement grout (SCCG) into granular packing without disturbing the granular skeleton culminates in the formation of a well-defined cemented granular materials (CGMs). The inherent attributes of both the cementing matrix and granular packing critically dictate the adhesion behavior and mechanical performance of CGMs. A succession of cement grout flow tests was conducted to elucidate the influence of particle size and the SCCG flowability on SCCG adhesion mechanism within granular packing. Furthermore, the influence of particle size and the cementing matrix volume on the mechanical characteristics of CGMs was scrutinized via uniaxial compressive testing. The results illuminate that the adhesion behavior of SCCG within granular packing is predominantly dependent on the yield stress of SCCG and the average particle size. Additionally, it is established that the peak strength of CGMs is intimately intertwined with the cementing matrix volume and the average particle size, as corroborated by a substantial aggregate of 135 uniaxial compression tests. • Cement matrix and particle size crucially impact CGMs' adhesion and mechanics. • SCCG flowability and particle size effects on SCCG adhesion in granular assessed. • Matrix volume and particle size effects on CGMs mechanics studied by uniaxial test. [ABSTRACT FROM AUTHOR]

Experiments on fluid flow in porous media, using fluids loaded with solids of various grain sizes, have been conducted in a modified Hele-Shaw setup. This setup utilised weakly cemented porous media with specific hydraulic and mechanical properties. Fluid injection in coarse granular media with clean or low-concentration fine particles, results in infiltration only, with pressure close to the material tensile strength, while injection in finer granular material causes damage alongside infiltration, with the fluid pressure still close to the material tensile strength. When larger particle sizes or higher particle concentrations are used in the mixture, the fluid travels further within the porous medium, primarily influenced by the grain size of the granular medium. In the latter case, the Darcy flow equation with an effective permeability term can be employed to determine the pressure differential. For the largest particle sizes included in the fluid, the equation is still applicable, but the effective permeability requires adjustment for particle size within the fluid rather than the granular medium. This is crucial when the injection point is locally clogged. The experiments show that fracturing conditions are controlled by different mechanisms. Dimensional and statistical analysis was used to classify the injection pressures to regimes predicted by fracturing theory or by Darcy law with modified effective permeabilities. The findings show that both the material properties and fluid composition are important designing parameters. • Fluid flow experiments are conducted in a modified Hele-Shaw setup. • The porous materials are generated via microbially induced carbonate precipitation. • Injection results in infiltration, damage, or a zone of lower permeability. • Fluids with solids of large particles and high concentrations promote infiltration. • Darcy flow equation with effective permeability determines pressure differential. [ABSTRACT FROM AUTHOR]