Pore size distribution measurements in swell‐shrink soils

Abstract

AbstractA method for the determination of pore size distribution in swell‐shrink soils was described. Undisturbed core samples, saturated and drained at 1.5 MPa suction, were filled with a non‐polar liquid (xylol), and its retention at suctions lower than 1.5 MPa was measured. Oven dry samples were analyzed in the same way. Derived pore size distributions were compared with those obtained by water desorption.Pore size distributions and their relative changes as a function of water content were related to some soil constituents and properties. Stability factor and sum of montmorillonite and vermiculite significantly influenced the pore size distribution by water release, A higher stability factor resulted in lower relative changes (ratios) in the pore size classes <10 μm and 0.2–10 μm when the samples were drained from saturation to 1.5 MPa suction, however, at extreme dryness, the relative changes were positively correlated to the sum of montmorillonite and vermiculite.