Abstract
Geogrids are beneficial in providing a stiffer pavement granular base/subbase by restraining lateral movement of aggregate particles, which improves pavement performance and/or extends pavement lifespan. The effectiveness of improvement due to geogrid depends on the interaction between geogrids and aggregates, involving various factors such as particle size and shape, geogrid geometry, and geogrid mechanical properties. This paper presents a comprehensive experimental study aimed at quantifying modulus improvement due to geogrid stabilization through shear wave measurements using bender element (BE) sensor technology. The experiments were conducted in both large-scale laboratory testbed and triaxial test setups. Two extruded geogrids were tested to evaluate modulus enhancement levels achieved through mechanical stabilization of a dense-graded aggregate base course material. The results from both experimental setups were compared, offering a comprehensive insight into geogrid stabilization effectiveness from two testing scales. The modulus enhancements presented herein are intended to provide mechanically stabilized aggregate layer inputs for different geogrid inclusions within the mechanistic-empirical (M-E) pavement design framework.