In-situ modulus assessment of geosynthetic-reinforced flexible pavements

In Surat, India, a total of 15 full-scale test sections were constructed to examine the performance of geosynthetic-reinforced flexible pavement. The impact of different factors, including the types of geosynthetics, their characteristics, and their placement locations, on the in-situ modulus of the pavement layer was assessed through Falling Weight Deflectometer (FWD) testing. The Modulus Improvement Factors (MIF) established from the three-year field study were found between 1.30 and 1.60 for the geocell-reinforcement, and Layer Coefficient Ratios (LCR) were found between 1.27 and 1.40 for the geogrid-reinforcement. FWD testing revealed an increasing trend in average base layer modulus values in February 2021 compared to initial readings from November 2019, indicating improved stiffness due to traffic compaction and reinforcement effects. However, a slight reduction in modulus was observed in July 2022, attributed to seasonal moisture infiltration from pre-monsoon rainfall. Additionally, deflection basin parameters were analyzed to assess the structural benefits of geosynthetic reinforcement.