Filtration and penetrability of cement-based grout: Study performed with a short slot

Filtration of cement-based grout during penetration through fractures in rock is an important issue while sealing the rock around tunnels. Whether a type of grout could be designed to penetrate a fracture of a certain aperture without filtration is an interesting question that needs to be further investigated. This study examines the question of whether grout penetration can be measured using our designed measuring method as well as which factors and processes influence the penetrability and filtration of the grout.The penetration and filtration of grout are complex processes influenced by many factors such as the grain-size curve of the cement, hydration and flocculation, pressure, grain concentration, and the geometry of constriction.The measured results were in agreement with the predicted results, indicating that the filtration process in the given geometry describes correctly.

► Penetration and filtration of cement-based grout has been studied with a short slot.
► Grouts based on cements with a d95 of 32 μm had the best penetrability.
► A high w/c ratio and high pressure improve penetrability.