Expansive Clay Mineralogy Effect on the Subgrade Stabilization Efficiency

Understanding of factors affecting unsuccessful road projects is a valuable experience to avoid their repetition in future. So, in this paper the reason of pavement failure of a road in north part of Hamedan province was studied. Also, the macro and micro structure tests were used to monitor the impact of quality and quantity of the clay mineral on the chemical stabilization efficiency of expansive soil. The results indicate that the presence of montmorillonite and anisotropy in the mineralogy of subgrade cause the road destruction. As can be seen in Fig.1, the soil samples obtaining from the site have different swelling potential due to variation in their mineral compositions and the differential heave in the pavement subsoil is grater than 80%. This condition contributes to uneven ground deformation and tension stress which has made pavement failure.