Performance evaluation of geocell-reinforced reclaimed asphalt pavement (RAP) bases in flexible pavements

Reclaimed asphalt pavement (RAP) materials have been considered as one of the most sustainable options in the pavement industry. However, the low shear strength and high permanent deformation behaviour of RAP materials often limit their application in road bases. Stabilisation of RAP bases using high-density polyethylene (HDPE) geocell was hence attempted in this study to assess the efficacy of three-dimensional geosynthetic reinforcements in improving the resilient properties of RAP materials and mitigating permanent deformation of them. The present paper discusses the results from a series of large-scale repeated load box tests conducted to study the effectiveness of HDPE geocell-reinforced RAP bases (GRRB). The performance of the geocell reinforcement was evaluated based on various parameters including resilient deformation, cumulative permanent deformation, resilient modulus, traffic benefit ratio (TBR), and rut depth reduction (RDR) factors. Test results show that HDPE geocell layer increased the resilient modulus of the RAP base layer by 2.5–3.3 times and reduced the permanent deformation of RAP base by 70–80% when compared to the unreinforced RAP bases. Test results were then used to perform pavement design to quantify the base thickness reduction with geocell reinforcement.