Air Permeability and Microstructure of a compacted silt treated with different binder dosages

Treating silt with hydraulic binders induces significant changes in soil microstructure, leading to changes in air permeability. The microstructure changes can be investigated using Mercury Intrusion Porosimeter (MIP), and the air permeability can be measured using the method proposed by Yoshimi and Osterberg. In this study, the evolution of air permeability in treated silt samples, compacted at the optimum Proctor density and cured for 7 days, was measured for varying binder dosages. These measurements were coupled with MIP observations to analyse and characterize the corresponding changes in microstructure. Results indicate that a marked population of macropores is formed with binder addition, which is more pronounced as the binder content increases. This macropore rise slightly increases the air permeability of soil. These findings shows that air permeability can be used as an indicator for the formation of fissures induced by the binder addition.