Use of Geocell for Reinforcing CDW in GSB of Flexible Pavements: An Experimental Investigation

In recent years, the surge in construction and demolition waste (CDW) has created significant disposal challenges. This study focuses on addressing the disposal challenges associated with the growing CDW by utilizing recycled materials reinforced with geocells. It aims to assess the performance of recycled concrete aggregates (RCA) and recycled asphalt pavement (RAP) for application in granular sub-base (GSB). Model pavement sections were constructed in the laboratory to compare the performance of conventional aggregates (CA), RCA, and RAP as infill materials under unreinforced and geocell reinforced conditions. The pavement sections were tested under repeated loading using haversine loading pattern to simulate the real-world traffic loading conditions. The research employed a comprehensive experimental approach, including instrumentation to measure settlement, pressure distribution, and strain along the reinforcement walls. Results demonstrated that geocell reinforcement significantly enhances the pavement performance, reducing plastic settlement by 27 to 41% compared to unreinforced sections. RCA exhibited comparable performance to CA, attributed to the self-cementation effect offered by the fine mortar present in RCA. However, RAP pavement sections exhibited premature failure due to the lower load-bearing capacity of RAP caused by the presence of adhered asphalt mortar and lack of support from weak subgrade. The provision of geocell reinforcement improved the rutting resistance of all the infill materials used in comparison with their respective unreinforced pavement sections. Geocell reinforcement reduced the accumulated residual pressure at the subgrade level by 28.6, 33.5, and 19.2% in the case of CA, RCA and RAP respectively. In geocell reinforced pavements, maximum strain is observed with RAP infill followed by RCA and CA infill materials. Life cycle cost analysis revealed substantial long-term economic benefits of geocell-reinforced pavements, with maintenance costs reduced by approximately 50% over a 20 year period. Overall, the study advances the geocell reinforcement technique to use RCA in bulk quantity in GSB application, offering sustainable, eco-friendly, economical, and long-lasting pavements.