The lack of a good foundation ground layer in some areas that could be used for construction proposes is a common problem all over the world. Today, more and more researches are focused on finding new solutions to improve the soil parameters in order to obtain a stabilized foundation layer. Finding an optimal admixture between the local soils, needed for construction purposes, hydraulic binders and the precise amount of water, may be the future of a revolutionary discovery in this field. The experimental study based on the admixture of a sandy silty clay with hydraulic binders from the Viacalco© [1] range, produced by Carmeuse Romania, in a percentage of 2%, 4% and 6% led to a significant improvement of the geotechnical parameters of the soil. The aim of this experimental study is to determine the optimal binder mixture in order to improve local soils and to obtain low investment costs.