Utilizing Grasspaver-Geocell as a Recycled Reinforcement Material in Flexible Pavement Base Layers: A Field Investigation

Geosynthetic materials, predominantly made from virgin synthetic polymers like high-density polyethylene (HDPE), are widely used to enhance pavement performance. However, growing environmental concerns surrounding plastic waste accumulation and pollution necessitate sustainable alternatives. This study investigates the application of the grasspaver-geocell, a recyclable geosynthetic material produced from HDPE waste, to address the problems of plastic waste and advance sustainable civil infrastructure. The investigation involved constructing three full-scale pavement sections in Dholera, Gujarat, India, including one reinforced with grasspaver-geocells, another with virgin HDPE-based geocells, and an unreinforced section. All sections comprised three layers, i.e., a lime-treated subgrade (6% lime), a subbase, and a base layer. The reinforcement materials (grasspaver-geocell and geocell) were placed within the base course. Plate load testing and falling weight deflectometer analysis were performed on all sections. Results indicate that the grasspaver-geocell reinforced section achieved a 40% higher load-bearing capacity, a 34% reduction in subgrade stress, and a 40%–60% improvement in the modulus of subgrade reaction compared to the unreinforced section. However, compared to the geocell-reinforced section, the grasspaver-geocell exhibited a 13% lower load-bearing capacity, 14% higher subgrade stress, 15% lower modulus of subgrade reaction, and 30% higher strain value at cell wall due to differences in height, seam strength, and surface texture. Despite these disparities, grasspaver-geocell reinforcement still demonstrated notable performance improvements over weak subgrades. The modulus improvement factor was 1.79 for the grasspaver-geocell and 1.98 for geocell-reinforced sections. Also, the annual greenhouse gas emissions ratio for the grasspaver-geocell reinforced sections was 46% lower than the unreinforced section and 2% lower than the geocell-reinforced section. The outcomes highlight the potential of grasspaver-geocell reinforcement as a viable and sustainable alternative for enhancing pavement performance on weak subgrades.