Key parameters for tensile and compressive strength of silt-lime mixtures

A dosage methodology for lime-treated soils has previously been established based on rational criteria where the porosity/lime ratio plays a fundamental role in the assessment of the target unconfined compressive strength (q(u)). The present research extends this previous work by quantifying the influence of the amount of lime, the porosity and the porosity/lime ratio in the assessment on tensile strength (q(t)) of soil-lime mixtures, as well as in the evaluation of the q(t)/q(u) relationship. A programme of splitting tensile tests and unconfined compression tests considering three distinct dry unit weights and four lime contents, varying from 3 to 9%, was carried out in the present study. The results show that a power function fits q(t) and q(u) values well with increasing volumetric lime content and a power function fits q(t) and q(u) values well with reducing porosity of the compacted mixture. The porosity/lime ratio is demonstrated to be an appropriate parameter to assess both q(t) and q(u) of the silt-lime mixture studied. Finally, the q(t)/q(u) relationship is unique for the silt-lime studied, being independent of the porosity/lime ratio.