Behaviour of the Pavement Subgrade Reinforced with Coir Geocells Under Repeated Loads

Abstract

This study investigates the performance of natural coir geocell–reinforced sandy subgrades through repeated plate loading tests. Key parameters were evaluated under simulated traffic loading, including load-settlement behaviour, elastic rebound, and cumulative permanent deformation (CPD). Coir geocell reinforcement reduced CPD by 42%, improved resilient modulus by nearly 67%, and achieved a traffic benefit ratio (TBR) of 23 at a rut depth of 33 mm. Mechanistic-empirical pavement analysis demonstrated a 40% reduction in base course thickness and a 22% reduction in overall granular layers for pavements designed for 10 million standard axles. These results demonstrate the effectiveness of three-dimensional coir geocells in improving subgrade resilience under repeated loading conditions. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2025.