Resilient Modulus as a Technical Parameter for Evaluating the Cement-Stabilized Soil

The design and construction of road pavement substructures involves compacting aggregate in conditions close to optimum moisture content. The recommendation introduced by AASHTO, obliges designers to use mechanistic-empirical design methods by using the resilient modulus. The value of cyclic resilient modulus is determined based on cyclic triaxial tests, in which elastic axial strain and cyclic deviator stress are measured. Laboratory tests were performed on natural (gravelly sand) and chemically stabilised (CEM I 42.5 R) soil. The study compared the effect of different cement additives (1.5, 3.0, 4.5, 6.0%) on the resilient modulus tested on samples which were compacted using the Standard Proctor method. The addition of cement increased the stiffness of the soil and the resilient modulus, while the elastic axial strain has decreased. The samples were tested after 7 and 28 days of care. A longer period of treatment increased the resilient modulus. The gravelly sand stabilised with cement obtained high values of resilient modulus.