Performance of coir geocell reinforced construction and demolition waste as a base course material

The construction of the base course relies heavily on conventional aggregates, leading to a significant depletion of natural resources. This study explores the use of construction and demolition waste (CDW) as an alternative to natural aggregate as a base course material in low-volume roads. Furthermore, the impact of using cashew nut shell liquid treated coir geocell reinforcement as a sustainable, durable and high-performance reinforcement to enhance the structural performance of the base course is also studied. The research involved conducting monotonic and repeated plate load tests on a flexible pavement model, revealing that coir geocell reinforcement significantly improved bearing capacity and modulus of subgrade reaction, with CDW performing better than natural aggregates. The Modulus Improvement Factor (MIF) ranged from 1.21 to 1.7 for natural aggregates and from 1.33 to 1.88 for CDW. Reinforcement with coir geocell was highly beneficial under repeated loads too. This reduced the plastic deformation and increased the elastic settlement of the pavement by facilitating better stress redistribution and particle interlocking. The study also proposed an analytical formulation to determine the effect of coir geocell wall flexibility on load-carrying capacity.