Use of Geosynthetics for Sustainable, Economical, and Durable Road Pavement Structures

Traditional road pavement construction methods rely heavily on quarried gravel. Thicker layers of granular material are often required when dealing with weak or soft ground conditions to mitigate the stresses exerted on the underlying soft subgrades. The depletion of natural resources, environmental issues associated with quarrying processes, and the global shift toward achieving net-zero emissions compel researchers and practitioners to investigate innovative materials and technologies that can enable the construction of sustainable, resilient, cost-effective, and environmentally friendly road pavements while reducing reliance on quarried gravel. In pursuit of this objective, this study focuses on the utilization of geosynthetics to stabilize soft subgrades, thereby diminishing the need for substantial granular cover thickness. and enhancing the overall performance of the pavement structure. To achieve this aim, a series of model pavements were constructed within a 1 m x 1 m × 1.2 m steel box (referred to as the model box). Various parameters, including subgrade stiffness, capping layer thickness, and geosynthetic types, were systematically altered during the construction of these models. Subsequently, the static plate load tests were conducted in a controlled laboratory environment. The test results provided valuable insights into the overall modulus/stiffness of the improved subgrade. The enhanced subgrade modulus, in turn, was integrated into the Australian granular pavement design chart to illustrate the advantages of geosynthetic embedment in soft subgrade stabilization. The findings from this study suggest that the incorporation of geosynthetics can reduce the overall granular cover thickness by approximately 20%.