Behavior of geocell-reinforced granular base under repeated loading

Major factors that influence the design of paved and unpaved roads are the strength and stiffness of the pavement layers. Among other factors, the strength of pavements depends on the thickness and quality of the aggregates used in the pavement base layer. The strength of pavement increases with increase in the thickness of the base which has a direct implication on construction cost whereas decreasing the thickness of the base makes it weak which results in low load bearing capacity especially for unpaved roads. Due to the lack of availability of aggregates, there is a need to identify alternative methods to minimize the thickness of the base without compromising on the strength of base. The use of geocell, a type of geosynthetics is a potential and reliable solution and studies are conducted in this direction. In the current study the performance of geocell reinforced base layer subjected to repeated loading is investigated. The results of the study are examined in terms of the resilient deformation and permanent deformation for different thicknesses of base layers under different repeated loading. The results showed that geocell reinforces the unbound aggregate thus reducing the deformation along with the reduction in the required thickness of the aggregate layer of unpaved roads. The amount of reduction of permanent deformation is found to be more for reinforced layer with higher thickness. The results also showed that the reinforced layers achieved maximum rut depth reduction compared to unreinforced section. The permanent deformation model modified for the geocell reinforced condition is calibrated using numerical analysis and the model can be used to predict the deformations for higher number of load cycles.