Assessing Failure Envelopes of Soil-Fly Ash-Lime Blends

This study aims to establish the influence of curing time and the amount of lime and porosity in the assessment of the Mohr-Coulomb failure envelope of fly ash-lime-treated soils based on unconfined compressive strength (sigma c) and splitting tensile strength (sigma t) of such materials. Founded on the concept that the sigma t/sigma c relationship is unique for each specific fine-grained soil, fly ash, and lime blends, it is shown that the angle of shearing resistance of a given lime-treated soil is independent of the porosity and the amount of lime of the specimen and that cohesion intercept is a direct function of sigma c (or sigma t) of the improved soil, which depends of the porosity and volumetric amount of lime of the soil-fly ash-lime blends. Finally, the concepts are tested with success for a sandy soil treated with fly ash and lime at distinct curing time periods, considering moderate to strong cementation levels.