Rutting performance of geosynthetic reinforced unbound pavements subjected to repetitive loading: A review

The growing demands on global infrastructure highlight the critical need for durable and efficient pavement systems, particularly under the stress of repetitive heavy traffic loads. The use of Geosynthetics within the pavement structure increases the load-carrying capacity of unbound pavement layers by providing lateral restraint, improving vertical stress distribution, and enhancing bearing capacity. Such reinforcement typically aims to either improve the service life of pavements or achieve equivalent performance with a reduced granular cover. Previous and ongoing research quantifies geosynthetic performance in pavement reinforcement using various testing methods. Among these, Laboratory Model Box Tests subjected to cyclic loading are pivotal, as they closely replicate real-world traffic conditions. Hence, these studies are essential for understanding how geosynthetics distribute loads and enhance pavement durability. This facilitates the development of optimized geosynthetic design and installation practices, accelerating the loading process to simulate years of traffic wear in a shorter period. This review discusses the improved rutting resistance of unbound pavements reinforced with geosynthetic materials, specifically drawing on data from cyclic plate load tests conducted on laboratory model boxes, as highlighted in the literature. Key variables such as optimum geosynthetic placement, geosynthetic material properties, performance of different geosynthetic materials and the effects of aperture shape and size on rutting resistance are discussed. Furthermore, the review assesses various predictive rutting models, analysing their applicability and accuracy in forecasting the rutting performance of geosynthetic-reinforced unbound pavements. This comprehensive literature review aids pavement engineers and researchers, in guiding the selection and design of geosynthetics to optimize pavement durability and functionality under repetitive traffic loads.