Compressional behaviour of various size/shape sand–clay mixtures with different pore fluids

Sand–clay mixtures can be considered as a composite matrix of coarser and finer particles. Nature of the interaction between coarser (sand) and finer (clay) particles can be demonstrated using intergranular void ratio (es), and transition fines content (FCt). The common aspect of the intergranular void ratio equations is based on the determination of an empirical relationship between es and effective stresses (σ′), fines content (FC), and void ratio (e). However, there is a lack of theoretical basis for determining consistent es and FCt values. This paper presents an investigation carried out to relate the various sizes (0.3 mm–0.6 mm; 1.0 mm–2.0 mm) and shapes (R = 0.43, S = 0.67; R = 0.16, S = 0.55) of sands with clay in different viscosity pore fluids (0.94 mm2/s; 10.65 mm2/s) to compressional behaviour by determining es and FCt values. Oedometer tests performed during this investigation indicate that the higher viscosity pore fluid in a specimen could cause a lower compressibility, and the sand with lower roundness (R) and sphericity (S) values exhibit higher FCt and Cc–s values.