Abstract:
The geotechnical properties of soils differ from area to area, depending on the origin
of soil, environmental conditions of a region, and soil treatment processes. As a subgrade
material in pavement construction, however, the soil is required to meet specific standards for
its engineering properties, such as plasticity, deformability, strength, and durability parameters.
For this purpose, soil undergoes a stabilization process, in which it is treated with chemical
additives. This paper studies the potential of limestone powder as a stabilizer in combination
with cement in the stabilization of sulfate-contained saline soil. For this purpose, silty sand (A2-4(0) according to AASHTO soil classification system) containing high sulfate and sodium
contents was stabilized with 6% and 8% cement by dry weight, 2% and 4% limestone powder
at fixed 4% cement content, and 2% limestone powder by dry weight at 6% cement content.
Series of tests were performed to determine the improvement of geotechnical properties of
these mixtures, such as unconfined compressive strength, Atterberg limits, three-dimensional
(3-D) swelling, and dielectric constant. Experimental results show that the addition of
limestone powder to the cement-treated saline soil decreases soil plasticity, increases
maximum dry density, improves strength parameter, reduces volumetric swelling and moisture
susceptibily of soil.