This article addresses the results of an experimental study on the behavior of soil; this soil was exposed to long -term treatment with lime and numerous wetting-drying cycles. This research investigated the effect of a wide range of lime contents on the soil volume, soil water content evolution and durability (unconfined compressive strength (UCS), plasticity index (PI) and cation exchange capacity (CEC)) for stabilized s oil in contact with water. This experimental study was performed on soil treated with lime (varying from no lime to 8%) corresponding to three levels of improvement: soil improvement only, stabilization and insensitivity to water, and long-term stabilization during wetting-drying cycles. The results indicated that the UCS increases, PI and CEC decreases with the lime level. For lime levels above 4%, the behavior of the treated soil under wetting -drying was satisfactory. Mineralogical analyses indicated that the formation of calcium silicate hydrate C-S-H, ettringite C-S-A-H is responsible for the increased or decreased strength of the treated soil. CaO, SiO2 and Al2O3 were three important minerals responsible for the increase or decrease in soil sample stabilization. Simple model executed in JMP statistical software was proposed and validated. We note that CaO and SiO2 have the most influential effects by very low values of probability for the responses studied, which confirms the hypothesis of that these models can be used to model UCS and PI in curing time and wett ing-drying cycles.

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Soil treatment technique with lime is widely applied in the world in the field of earthworks. It allows reuse of materials useless for implementation embankments. But the lack of knowledge of behavior of cycles, drying/wetting in terms of volume and water change, the mechanical performance of the treated soils, the optimal lime dosage are the origin of the limited application of this technique to embankment and the no mentioned in the GTS (technical Guide soil treatment with lime and/or hydraulic binders) of this technique. The soil studied is A-4. Lime dosages are chosen based on two objectives: the amelioration and stabilization to cycles drying/wetting of soil.

This article addresses the results of experimental study behavior of recycled soil treated with lime and exposed to wettingdrying cycles at the long term. The object of this research is to focus on effect of a wide range of lime content on evolution of volume and durability of stabilized soils, when exposed to wetting-drying cycles. In this work, an experimental study was performed on soils which were treated with 8 percentages (0-8%) of lime. Treated soils were conserved for three different periods of cure: 7, 28 and 180 days, and then exposed to 12 wetting-drying cycles of 48 hours for each cycle. However, the behavior under wetting-drying cycles was only satisfactory for lime percentages above 6%. The formation of C-S-H and C-A-H responsible for the increased strength of stabilized soil samples are showed and the expensive ettringite was also responsible for the decreased strength of stabilized soil samples.

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