Cement grout transport within sand with fractal characteristics considering filtration

Abstract

Filtration effect exists widely in the process of turbid fluid seepage in porous media, which directly influence the whole diffusion and migration process of turbid fluid particle. To better understand the effects of grouting parameters on the transport rules (e.g. velocity, viscosity and effective distance) of cement-based particle considering filtration, laboratory tests were carried out on fractal characteristics’ sand, with different grouting pressure, confining pressure, water/cement and mass fractal dimension taken into account. In this study, the mechanism governing the transport of particles was investigated by analysing the variety of velocity and viscosity of slurry at the column outlet, as well as the porosity of specimens at different grouting parameters. The results indicated that (1)The viscosity of passed grouts and the effective range is increasing firstly and then decreasing with the grouting pressure; (2) The viscosity increases non-linearly when the water/cement ratio is less than 3.0, beyond which it decreases slowly; (3) The effective range presents non-linear increasing firstly and then decreasing with increase of water/cement ratio; (4) The viscosity increases non-linearly firstly, and then decreases rapidly with increase of mass fractal dimension; (5) The effective range decreases when the fractal dimension increases.

Keywords:

• Cement grout
• porous media
• particles transport
• central composite design
• filtration

Acknowledgements

The authors wish to acknowledge their financial support for this basic research.