Quantifying Geogrid Benefits in Highway Pavements with In Situ Testing and Bender Element Field Sensors

Geogrids can enhance pavement performance by forming a mechanically stabilized layer (MSL). There is a lack of detailed data quantifying geogrid benefits and load-related stress effects on MSL stiffness distribution in highway pavement sections. This study utilizes state-of-the-art in situ testing equipment, i.e., the Automated Plate Load Testing (APLT), and embedded sensors, e.g., Bender Element (BE) field sensors, to assess the benefits of geogrid-stabilized unbound aggregate layers in highway pavements. The paper reports on three 250-ft long pavement sections during the reconstruction of the US-20 highway in Elkhart, Indiana. The sections included one control section and two sections with geogrids installed at different depths. Results indicate that the sections with geogrids showed higher resilient modulus and reduced deformation, with local stiffness enhancements observed near the geogrids. These findings provide crucial insights for moving towards a mechanistic design of geogrid-stabilized highway pavement base layers.