The use of lime as additive to soil is a very
common technique in engineering projects. The purposes of
this proceses are the increase in strength and a decrease in
plasticity behaviour of the soil. The results of this research
indicate that in the chemical interaction process of soil
minerals with lime, a part of minerals, specifically clay
minerals, transform to other minerals. In fact, this
transformation is the base for the different mechanical
response of soil. In the present study, attention is made to the
tri-calcium-silica-hydrate (CSH), tetra-calcium-alumnahydrate
(CAH), and ettringite, as the three major minerals
formed in this process. This transformation is monitored by
use of scanning electron microscope and x-ray diffraction
testing.