Empirical Relationships with Unconfined Compressive Strength and Split Tensile Strength for the Long Term of a Lime-Treated Silty Soil

Abstract

Fine-grained soils have a low load-bearing capacity that hinders their use in pavement construction, slope protection, or foundation support. Therefore, the chemical stabilization of a soil with the addition of lime is a viable technique that could enable its use in civil construction. Unconfined compressive strength (UCS) and split tensile strength tests were performed to evaluate the improvement of a soil with lime and the existing correlation between these two tests. This study aims to determine the empirical relationships between the split tensile strength (qt) and UCS (qu) of a silty soil artificially cemented with hydrated lime (L). To calculate the qt/qu ratio, soil–lime specimens are molded by controlling the dry unit weight, lime content, porosity, and water content, followed by curing for 15, 3, 6, 9, and 18 days. The voids/lime relationship determined by the porosity/volumetric lime content ratio (η/Lv) plays an essential role in this study, and it is the principal parameter used to assess the increases in qt and qu and determine their empirical relationship. The results demonstrate that qt/qu=.16 for all curing times (15–18 days), so that it is an overall constant relationship (qt/qu). Moreover, with the addition of 9% lime, maximum resistances of qt (7 kPa) and qu (3,75 kPa) are obtained for the soil–lime mixtures after 18 days of curing. Moreover, two dosage equations that can be used as mix design relationships are obtained to determine the qt and qu of the lime-treated soils.