LL (%) = 43.202 e-0.015HL (1)
The best relationship between plasticity index (PI) and used hydrated lime content, as compared to the plastic limit (PL) and used hydrated lime content can be seen in Figure 4 in the form of polynomial equations with the coefficient of determination R2 equal to 0.8181 and 0.7204 respectively and the corresponding non-linear equations as follows: